nx nastran 11 release guide - smart-fem.de · pdf filenx nastran 11 release guide. contents...

SIEMENSSIEMENSSIEMENS

NX Nastran 11Release Guide

Contents

Proprietary & Restricted Rights Notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

NX Nastran 11 summary of changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

NX Nastran 11 summary of changes to default settings and inputs . . . . . . . . . . . . . . . . . . . . . 1-1

Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Shell and solid composites in random analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1Modal frequency response improvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Performing multiple random analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Exterior acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1Microphone mesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Modal and panel contributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16Support for one-way acoustic coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16Acoustic coupling data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19Adding pre-computed enforced vibrations at fluid-structure interface . . . . . . . . . . . . . . . . . . 3-23Support for porous materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23System cell to revert acoustic behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25New Acoustics User's Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26

Rotor dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Mode filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1MODTRK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Complex eigenvalue and frequency response analysis enhancements . . . . . . . . . . . . . . . . . . 4-5Load specification options for maneuver load analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9Synchronous modes in complex modal solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13Expanded support for coupled solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19Expanded support for superelement style reduction of rotors . . . . . . . . . . . . . . . . . . . . . . . . 4-19Superelement reduction of support structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22

Multi-step nonlinear solution 401 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

Cyclic symmetric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1Fourier harmonic solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27Parallel solution options with SOL 401 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-34Bolt preload . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-35Sliding glue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-44Contact improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-52User defined materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-67Initial stress-strain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-86Time-varying added stiffness for generalized plane strain elements . . . . . . . . . . . . . . . . . . . 5-97

NX Nastran 11 Release Guide 3

Contents

Chocking elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-99Cohesive elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-117Progressive failure analysis in solid composites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-129Element performance enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-145SOL 401 Caveats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-145

Advanced nonlinear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Advanced nonlinear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

GPU Computing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

GPU and MIC computing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

RDMODES improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

RDMODES automatic NREC computation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1RDMODES restart improvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

Optimization enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

Topology Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

NX Nastran Topology Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1

LP-64 and ILP-64 executables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1Convert 64-bit XDB file to 32-bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1Support for MAT11 with axisymmetric elements and 2D solid elements . . . . . . . . . . . . . . . . . 11-2Element geometry checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-8NX Nastran value-based licensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-15

Documentation changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1

Removing documentation for legacy axisymmetric elements . . . . . . . . . . . . . . . . . . . . . . . . 12-1Removing documentation for axisymmetric acoustic cavity modeling . . . . . . . . . . . . . . . . . . 12-1Removing documentation for p-elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2Removing documentation for curved elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2Addition of element utilization summary tables in the QRG . . . . . . . . . . . . . . . . . . . . . . . . . 12-2

Upward compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1

Updated data blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1CASECC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1CLAMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3CONTACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-4DYNAMIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-5EDOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-6EDT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-7EPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-8EPT705 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-9

4 NX Nastran 11 Release Guide

Contents

Contents

GEOM2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-10GEOM3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-13GEOM4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-14GEOM4705 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-15MPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-15OCCORF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-21OCPSDF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-21OEE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-21OES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-22OESVM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-51OESXRMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-64OGF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-66OPRESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-67OQG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-67OUG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-68SETMC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-68

New data blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-69ELRSCALV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-69OACCQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-70OACINT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-72OACPRES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-73OACPWR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-75OACVELO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-76OBOLT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-78OCCORFC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-79OCKGAP1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-81OCPSDFC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-83ODAMGCZD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-85ODAMGCZR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-86ODAMGCZT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-88ODAMGPFD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-89ODAMGPFE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-90ODAMGPFS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-92OUMAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-93

Updated modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-104ACMG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-104CASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-104CNTMAPTR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-105CNTSTAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-105CNTXTRAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-106CONSTF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-107CONTOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-108DLT2SLT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-108DOM10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-109DOM12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-109DOPR1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-110DPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-110ELTPRT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-111EMG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-111


Contents

Contents

EXTSEIDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-112FOCOEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-112FOELCS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-113FOGLEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-114GP4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-114GP5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-114GPFDR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-115IFP1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-115MATMOD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-116MODACC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-119NLTRD3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-120OPRESSDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-123OUTPRT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-124OUTPUT2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-124RANDOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-125ROTCZG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-125SDR2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-126TOPOPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-127UPGLSTF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-127VDRMC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-128

New modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-128CNTSLIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-128CYC_MPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-129EMAAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-131GPAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-132INITOES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-134INITSNCR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-135MODUSETF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-136MPPARV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-137MPPOST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-138MPPRES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-139MPSHAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-139RFRCCHK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-140SAMDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-140SPCSTRU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-141UMATDBL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-142

Problem Report (PR) fixes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-1

Problem Report (PR) fixes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-1

6 NX Nastran 11 Release Guide

Contents

Proprietary & Restricted Rights Notice

© 2016 Siemens Product Lifecycle Management Software Inc. All Rights Reserved.

This software and related documentation are proprietary to Siemens Product Lifecycle ManagementSoftware Inc. Siemens and the Siemens logo are registered trademarks of Siemens AG. NX is atrademark or registered trademark of Siemens Product Lifecycle Management Software Inc. or itssubsidiaries in the United States and in other countries.

NASTRAN is a registered trademark of the National Aeronautics and Space Administration. NXNastran is an enhanced proprietary version developed and maintained by Siemens Product LifecycleManagement Software Inc.

MSC is a registered trademark of MSC.Software Corporation. MSC.Nastran and MSC.Patran aretrademarks of MSC.Software Corporation.

All other trademarks are the property of their respective owners.

TAUCS Copyright and License

TAUCS Version 2.0, November 29, 2001. Copyright (c) 2001, 2002, 2003 by Sivan Toledo, Tel-AvivUniversity, [email protected]. All Rights Reserved.

TAUCS License:

Your use or distribution of TAUCS or any derivative code implies that you agree to this License.

THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED ORIMPLIED. ANY USE IS AT YOUR OWN RISK.

Permission is hereby granted to use or copy this program, provided that the Copyright, this License,and the Availability of the original version is retained on all copies. User documentation of any codethat uses this code or any derivative code must cite the Copyright, this License, the Availability note,and "Used by permission." If this code or any derivative code is accessible from within MATLAB, thentyping "help taucs" must cite the Copyright, and "type taucs" must also cite this License and theAvailability note. Permission to modify the code and to distribute modified code is granted, providedthe Copyright, this License, and the Availability note are retained, and a notice that the code wasmodified is included. This software is provided to you free of charge.

Availability (TAUCS)

As of version 2.1, we distribute the code in 4 formats: zip and tarred-gzipped (tgz), with or withoutbinaries for external libraries. The bundled external libraries should allow you to build the testprograms on Linux, Windows, and MacOS X without installing additional software. We recommendthat you download the full distributions, and then perhaps replace the bundled libraries by higherperformance ones (e.g., with a BLAS library that is specifically optimized for your machine). If youwant to conserve bandwidth and you want to install the required libraries yourself, download thelean distributions. The zip and tgz files are identical, except that on Linux, Unix, and MacOS,unpacking the tgz file ensures that the configure script is marked as executable (unpack with tarzxvpf), otherwise you will have to change its permissions manually.


Chapter 1: NX Nastran 11 summary of changes

NX Nastran 11 summary of changes to default settings and inputs

Default setting changes

Note

The following table lists changes to default settings that may produce differences inresults between NX Nastran 10 and NX Nastran 11. Default setting changes that produceadditional output only are not included in this table.

Input type Default changeKeywords

Nastran statement The nastran.exe and nastranw.exe commands run the ILP-64executable rather than the LP-64 executable

File management statementsExecutive control statementsCase control commandsParameters The default for WRTMAT has changed to 1

The default for PRGPST has changed to NO

Bulk entries The default for CONV1 on the DOPTPRM bulk entry has changedfrom 0.001 to 0.0001The default for CRCERAT on the NLCNTL bulk entry has changedfrom 0.1 to 0.4The default for CRTECO on the NLCNTL bulk entry has changedfrom 0.01 to 1.0E-4

Nastran statement changes

Systemcell System cell name System cell description Description of change

462 - - - Methods for SOL 111. Automatic selection of performancemethods.

617 ACFORM Reverts to previous acousticsbehavior. New system cell

635 Q8T6_ANG

Controls the maximum allowableangle between normals to cornergrids for CQUAD8 and CTRIA6elements. USER WARNINGMESSAGE 5276 is issued if themaximum allowable angle isexceeded.

New system cell

NX Nastran 11 Release Guide 1-1


Systemcell System cell name System cell description Description of change

636 TET_EPIAGEOMCHECK check value forCTETRA – edge point includedangle.

New system cell

637 HEX_EPIAGEOMCHECK check value forCHEXA – edge point includedangle.

New system cell

638 PEN_EPIAGEOMCHECK check value forCPENTA – edge point includedangle.

New system cell

639 PYR_EPIAGEOMCHECK check value forCPYRAM – edge point includedangle.

New system cell

File management statement changes

No changes to file management statements.

Executive control statement changes

Executive controlstatement Executive control statement description Description of change

GEOMCHECK Specifies tolerance values for (optional)finite element geometry tests.

Added edge-point-included-angle(EPIA) geometry tests for CTETRA,CHEXA, CPENTA, CPYRAM,CHEXCZ, and CPENTCZ elementswith midside grids.

Added cohesive elements CHEXCZand CPENTCZ, and chockingelements CCHOCK3, CCHOCK4,CCHOCK6, and CCHOCK8 to thetable of test keywords.

Case control command changes

Case controlcommand Case control command description Description of change

ACINTENSITY Requests acoustic intensity output atmicrophone points. New case control command

ACPOWER Requests acoustic power output forAMLREGs. New case control command

ACVELOCITY Requests acoustic velocity output atmicrophone points. New case control command

1-2 NX Nastran 11 Release Guide


NX Nastran 11 summary of changes


ANALYSIS Specifies the type of analysis beingperformed for the current subcase.

Cyclic normal modes subcaseis available in SOL 401for models which includeaxisymmetric elements. Thesubcase is designated with theANALYSIS=CYCMODES.

Fourier normal modes subcaseis available in SOL 401for models which includeaxisymmetric elements. Thesubcase is designated with theANALYSIS=FOURIER.

A bolt preload subcase requiresANALYSIS=PRELOAD andBOLTLD=n commands.(ANALYSIS=STATICS doesno longer support bolt preloadsubcases.)

Random analysis subcase isavailable in SOLs 108 and 111.The subcase is designated with theANALYSIS=RANDOM case controlcommand in the subcase.

BCSET Selects the contact set for SOLs 101, 103,105, 111, 112, 401, 601 and 701.

BCSET can now be defined in astatic subcase for SOL 401 only.

BCRESULTS Contact Result Output Request (SOLs 101,103, 111, 112, 401, 601, and 701).

SEPDIS describer is now supportedby SOLs 601 and 701.

BGRESULTS Glue Result Output Request (SOLs 101,103, 105, 401, and 601).

Added new SEPDIS describer torequest slide distance output.

Added support for Sol 601.BOLTRESULTS Requests bolt results output in SOL 401. New case control command

CKGAP Requests gap result output for chockingelements in SOL 401. New case control command

CYCFORCESRequests MPC force output at the gridpoints selected for the automatic coupling ina SOL 401 cyclic symmetry analysis.

New case control command

CYCSET Selects a cyclic symmetric boundarycoupling in SOL 401. New case control command

CZRESULTS Requests results output for cohesiveelements in SOL 401. New case control command

DTEMPSelects a time-assigned temperature set tobe used for temperature dependent materialproperties and thermal loading.

Added support for SOLs 601 and701.





FLSTCNT Miscellaneous control parameters forfluid-structure interaction.

Describer SKINOUT has beenenhanced to write out coupling datato OACCQ output data block in an.op2 file.

HARMONICSRequests the solution harmonics for cyclicsymmetry and axisymmetric models insolutions 114, 115, 116, 118, and 401.

Case control has been enhanced tosupport SOL 401.

Describer h and NONE have beenremoved.

HOUTPUTRequests harmonic output for cyclicsymmetry and axisymmetric models insolutions 114, 115, 116, 118, and 401.

Case control has been enhanced tosupport SOL 401.

INITS Selects an initial stress or strain set. New case control command

MODCON Requests modal contribution results for theresidual.

Case control has been enhancedto support results for MICPNTmicrophone points (0D microphoneelements).

MONVARSelects degree-of-freedom for adisplacement monitor plot in a SOL401 run with Simcenter Multiphysics.


OLOAD Requests the form and type of applied loadvector output.

Added support for SOLs 601 and701.

OSTNINI Requests initial strain output in SOL 401. New case control command

PANCON Requests acoustic panel contribution resultsfor the residual.

Case control has been enhancedto support results for MICPNTmicrophone points (0D microphoneelements).

PFRESULTS Requests progressive failure results outputfor composite solid elements in SOL 401. New case control command

SETMCNAMESpecifies the title of a displacement monitorplot in a SOL 401 run with SimcenterMultiphysics.


STATVAR Requests output of state variables with SOL401. New case control command

Parameter changes

Parameter Parameter description Description of change

AFZERO

Frequency threshold in units of hertz usedby the SOL 401 cyclic and Fourier subcasetypes to determine if a mode is a rigid bodymode when AF normalization is requested.

New parameter

FRUMIN Allows frequency-dependent elements to beconnected to o-set degrees-of-freedom. New parameter

MODTRK Specifies mode tracking algorithm forcomplex eigenvalue rotor dynamic analysis. Added MODTRK = 4 option.

ODSRequests an efficient RDMODES restartmethod which reduces the amount ofeigenvector restart data.

New parameter




Parameter Parameter description Description of change

RLOOPNEW

For complex eigenvalue and frequencyresponse rotor dynamic analysis, includesgyroscopic and circulation terms in mass,damping, and stiffness matrices when theanalysis is performed in the fixed referencesystem.

New parameter

SEOP2CV

Overrides the effect of PARAM,OP2FMTwhen the .op2 file is created by theEXTSEOUT case control command onILP64.

New parameter

SPCSTRConstrains structural DOFs in the analysisset, but only after the structural excitation istransferred over to the fluid.

New parameter

Item code changes

No changes to item codes.

Degree-of-freedom set changes

No changes to degree-of-freedom sets.

Bulk entry changes

Bulk entry Bulk entry description Description of change

ACMODLDefines modeling parameters forthe interface between the fluidand the structure.

Added option for turning on strong or weakacoustic coupling.

AMLREGDefines automatically matchedlayer region for acousticsanalysis.

New bulk entry

BCRPARA Defines parameters for a contactface or edge region.

For subcases which have a constant time, thesoftware automatically increments the contactoffset using the number of increments. Thenumber of increments is defined with either theNinc field on the TSTEP1 entry, or with the Nincfield on the BOLTSEQ entry.

BCTPARMSurface-to-Surface ContactParameters (SOLs 101, 103,111, 112, and 401).

Added option to delay contact friction to helpalleviate convergence problems.

BGPARM Control parameters for the gluealgorithm. Added SLIDE parameter for sliding glue.

BOLTFRCDefines bolt preload force,displacement, or strain in SOL401.

New bulk entry

BOLTSEQ Specifies a bolt preloadsequence in SOL 401. New bulk entry





CCHOCK3

Defines a 2D chocking triangularelement connection. Valid forSOL 401 axisymmetric analysisonly.

New bulk entry

CCHOCK4

Defines a 2D chockingquadrilateral element connection.Valid for SOL 401 axisymmetricanalysis only.

New bulk entry

CCHOCK6

Defines a 2D chocking triangularelement connection. Valid forSOL 401 axisymmetric analysisonly.

New bulk entry

CCHOCK8

Defines a 2D chockingquadrilateral element connection.Valid for SOL 401 axisymmetricanalysis only.

New bulk entry

CHEXA Six-Sided Solid ElementConnection. Added PMIC to the PID list.

CHEXCZ

Defines the connections of thesix-sided cohesive element witheight to twenty grid points. Validfor SOL 401 only.

New bulk entry

CPENTA Five-Sided Solid ElementConnection. Added PMIC to the PID list.

CPENTCZ

Defines the connections of thefive-sided cohesive element withsix to fifteen grid points. Valid forSOL 401 only.

New bulk entry

CPYRAM Five-Sided Solid ElementConnection. Added PMIC to the PID list.

CQUAD4 Quadrilateral Plate ElementConnection. Added PMIC to the PID list.

CRODDefines atension-compression-torsionelement.

Added PMIC to the PID list.

CTETRA Four-Sided Solid ElementConnection. Added PMIC to the PID list.

CTRIA3 Triangular Plate ElementConnection. Added PMIC to the PID list.

CYCSET Defines pairs for cyclic symmetryin SOL 401. New bulk entry.

CYCADD Combines cyclic symmetry setsin SOL 401. New bulk entry.

CYCAXISDefault cylindrical coordinatesystem for a SOL 401 cyclicmodel.

New bulk entry.

DOPTPRMOverrides default values ofparameters used in designoptimization.

Added new EDVOUT parameter.





DVEREL1 Automatic shell elementthickness design variable. New bulk entry.

DTEMP Defines a time dependenttemperature set. Added support for SOLs 601 and 701.

INITADD Combines multiple initial stressor initial strain sets in SOL 401. New bulk entry.

INITS Defines initial stress or strainstate in SOL 401. New bulk entry.

IPLANE Defines infinite plane foracoustics analysis. New bulk entry

MAT3

Defines linear orthotropicmaterials for the axisymmetricelements CQUADX4,CQUADX8, CTRAX3,CTRAX6; the plane strainelements CPLSTN3, CPLSTN4,CPLSTN6, CPLSTN8; and theplane stress elements CPLSTS3,CPLSTS4, CPLSTS6, CPLSTS8.

Added note that except for axisymmetric models inSOL 601, 701, the use of MAT11 is recommendedfor defining orthotropic materials for axisymmetricelements and 2D solid elements.

The MAT3 bulk entry is scheduled to beundocumented in the next version of NX Nastran.

MAT11

Defines the orthotropic materialproperties for axisymmetricelements, 2D solid elements,3D solid elements, and 3D solidcomposite elements.

Added support for axisymmetric elements, 2Dsolid elements, and 3D solid composite elements.

MATCZDefines damage model andmaterial properties for cohesiveelements. Valid for SOL 401 only.

New bulk entry

MATDMG

Defines damage-related materialproperties for progressiveply failure in composite solidelements. Valid for SOL 401only.

New bulk entry

MATPORDefines material propertiesfor porous materials used asacoustic absorbers.

New bulk entry

MICPNT Defines microphone point foracoustic analysis. New bulk entry

MUMATDefines the material propertiesfor the user defined materialsubroutine in SOL 401.

New bulk entry

NLCNTL Defines solution controlparameters for SOL 401.

Added new parameters:

AUTOTIM, CNTMDIV, EQMFMIN, EQMFMX,FRICDLY, FSYMTOL, KSYM, KSYMTOL, LVAR,MISFBLT, MSGLVLB, MSGLVLC, TSCEQ,TSCUMAT, UMFMIN, UMFMX, USOLVER, andZERBOLT.

PCHOCK Defines properties for CCHOCKielements. Valid for SOL 401 only. New bulk entry





PCOMPS

Defines the properties of an n-plycomposite material laminatefor CHEXA and CPENTA solidelements.

Added progressive ply failure option.

PGPLSN

Defines the properties ofgeneralized plane strainelements. Valid for SOL401 only.

Added capability to define time-varying addedstiffness.

PMICDefines dummy property formicrophone elements foracoustic analysis.

New bulk entry

PSOLCZDefines the properties ofcohesive elements. Valid forSOL 401 only.

New bulk entry

RCROSSC

Defines a pair of responsequantities for computing thecross-power spectral densityand cross-correlation functionsin random analysis for laminatecomposites.

New bulk entry

RFORCEDefines a static loading conditiondue to an angular velocity and/oracceleration.

Describer RACC is supported by SOLs 601 and701.

RFORCE1Defines a static loading conditiondue to an angular velocity and/oracceleration.

Describer RACC is supported by SOLs 601 and701.

RFORCE2

Defines a static loading conditiondue to an angular velocityand/or angular acceleration formaneuver load rotor dynamicanalysis. Valid for SOL 101 only.

New bulk entry

ROTORD Defines rotor dynamics solutionoptions.

Added option for selecting synchronous modesonly in a SOL 107 or SOL 110 complex eigenvaluerotor dynamic analysis.

ROTPARM

Defines solution controlparameters for complexeigenvalue and frequencyresponse rotor dynamic analysis.

New bulk entry

ROTSE

Defines the modal reduction typeand additional a-set grids for arotor superelement. Valid forSOLs 107, 108, and 109.

Expanded solution support for superelement stylereduction of rotors to include SOL 108 directfrequency response rotor dynamic analysis andSOL 109 direct transient rotor dynamic analysis.



Chapter 2: Dynamics

Shell and solid composites in random analysisBeginning in NX Nastran 10, you could include shell and solid element composites in the frequencyresponse solutions 108 and 111 for a random analysis. However, cross-power spectral density andcross-correlation functions were not supported.

In NX Nastran 11, a new RCROSSC bulk entry is available to request cross-power spectral densityand cross-correlation functions for shell and solid element composites. With the new RCROSSC bulkentry, you can:

• Define the type of response quantities between which NX Nastran calculates the cross-powerspectral density function or cross-correlation function.

• Specify the element, grid point, or scalar point and the corresponding component code that NXNastran uses in the cross-power spectral density function or cross-correlation function calculation.

• Specify the ply numbers of the shell or solid composite for which to compute the responsequantities. You specify the ply numbers in the PLYi fields on the RCROSSC bulk entry.

• Specify that the cross-power spectral density function or cross-correlation function be calculatedbetween a laminate and a non-laminate. To do so, enter zero in the PLYi field of the responsequantity that is associated with the non-laminate.

For situations where both response quantities are associated with non-laminates, you must use theRCROSS bulk entry.

For more information, see the new RCROSSC bulk entry.


Chapter 2: Dynamics

RCROSSC

Cross-Power Spectral Density and Cross-Correlation Function Output for Shell andSolid Element Composites

Defines a pair of response quantities for computing the cross-power spectral densityand cross-correlation functions in random analysis for shell and solid elementcomposites.

FORMAT:

1 2 3 4 5 6 7 8 9 10RCROSSC SID RTYPE1 ID1 COMP1 PLY1

RTYPE2 ID2 COMP2 PLY2 CURID

EXAMPLE:

RCROSSC 20 DISP 50 2

STRESS 150 8 2 4

FIELDS:

Field Contents

SID RCROSS case control command identification number. (Integer>0)

RTYPEi Response quantity. (Character; For default behavior, see Remark 2)

IDi Element, grid, or scalar point identification number. (Integer > 0; Nodefault)

COMPi Component (item) code identification number. See Remark 3. (Integer> 0; No default)

PLYi Ply number. (Integer ≥ 0; For default behavior, see Remark 4)

CURID Optional curve identification number. See Remark 5. (Integer > 0;No default)

REMARKS:1. The RCROSSC entry is used to request cross-power spectral density and

cross-correlation function output for shell composites defined with the PCOMPand PCOMPG property entries, and solid element composites defined with thePCOMPS property entry.


Chapter 2: Dynamics

Dynamics

2. The keywords for field RTYPEi are listed as follows:

Keyword Meaning

DISP Displacement Vector

VELO Velocity Vector

ACCEL Acceleration Vector

OLOAD Applied Load Vector

SPCF Single-point Constraint Force Vector

MPCF Multi-point Constraint Force Vector

STRESS Element Stress

STRAIN Element Strain

FORCE Element Force

If either the RTYPE1 or RTYPE2 field is blank, then the blank field defaults to theresponse quantity listed in the defined field.

3. For elements, the component (item) code COMPi represents a component of theelement stress, strain or force as described in the “Element Stress (or Strain) ItemCodes” and “Element Force Item Codes” tables. For an item having both a realand imaginary part, the code of the real part must be selected. This is required forcomputing both the cross-power spectral density function and cross-correlationfunction.

For grid points, the item code is one of 1,2,3,4,5, and 6, which represent T1, T2,T3, R1, R2, and R3, respectively.

For scalar points, always use 1.

4. PLY1 and PLY2 cannot both be zero or blank. If it is desired to have both zero,use the RCROSS bulk entry.

For a non-composite element, grid point, or scalar point, specify PLYi = 0 or leavethe PLYi field blank. For a non-composite element, grid point, or scalar point, ifPLYi > 0, the ply number specification is ignored.

For a composite element, if PLYi = 0 or the PLYi field is blank or PLYi is greaterthan the actual number of plies, the ply number specification is ignored.

5. To identify the output with a single index, specify the index in the CURID field.

Modal frequency response improvementWhen structural or viscous damping is included for a modal frequency response solution (SOL 111),the orthogonality property of the modes generally does not diagonalize the stiffness or dampingmatrices. Consequently, the equations of motion are typically coupled.


Dynamics

Chapter 2: Dynamics

Performance methods are available to solve these problems more efficiently. For example, thein-core FRRD1 method was introduced in NX Nastran 9, and is supported in a serial or SMP run.However, the memory requirement increases quickly with this method as the number of modesand number of SMP cores increase.

Beginning in NX Nastran 11, an in-core FRRDRU method is now available to solve these problemsefficiently and with moderate memory usage. The new method is supported in a serial, SMP, or aDMP run.

Now when you run with SYSTEM 462=1 (default), the software automatically selects the new in-coreFRRDRU method or a FRRD1 method. The default setting is recommended for most models andrun types.

When SYSTEM 462=1 (default), the automatic selection is as follows:

• The software selects the original FRRD1 method if the model includes any of the following:frequency dependent properties or materials, unsymmetric damping, or consists of only fluidelements.

• If the model does not include any of the items listed above and the number of modes <PARAM,FRUMIN (default=500), the software selects the in-core FRRD1 method if there isenough memory to solve in-core. Otherwise, the original FRRD1 method is selected.

Note: If you define SYSTEM(262)=YES and the in-core FRRD1 method is selected by thesoftware, an in-core iterative method is used.

• The software selects the in-core FRRDRU method if the model does not include any of the itemslisted above and the number of modes ≥ PARAM,FRUMIN.

You can verify which method the software selected by viewing the .f06 file.

• If SQFREQ or DPFREQ are printed, the original FRRD1 method was used.

• If FRDSMP is printed, the in-core FRRD1 method was used.

• If FRRUD1 or FRRUD2 are printed, the new in-core FRRDRU method was used.

When SYSTEM 462=0, the automatic selection is as follows:

• The software selects the original FRRD1 method if the number of modes < PARAM,FRUMIN(default=500), or if the model includes any of the following: frequency dependent properties ormaterials, unsymmetric damping, or consists of only fluid elements.

• The software selects the in-core FRRDRU method if the model does not include any of the itemslisted above and the number of modes ≥ PARAM,FRUMIN.

If you are using the setting SYSTEM 462=0, you can optionally define the new parameter settingPARAM,FRRU,NO to turn off the automatic selection and request that the software always usethe original FRRD1 method.

Performance Example

Original FRRD1 (SMP=8) In-core FRRDRU (SMP=8) In-core FRRDRU (SMP=16)440 minutes 18 minutes 11 minutes


Chapter 2: Dynamics

Dynamics

Performing multiple random analysesIn NX Nastran 11, the ANALYSIS case control command now includes the RANDOM subcase typefor SOLs 108 and 111. With the new RANDOM type, you can streamline the process of performingmultiple random analyses with the RANDOM and optionally RCROSS case control commands overfrequency response subcases of the same frequencies.

For example, in SOL 111:

SDAMPING=101SPC=2ACCELERATION(RPRINT)=ALLSTRESS(SORT2,PSDF)=ALLRCROSS(PRINT)=1METHOD=1$SUBCASE 1 $ Normal ModesANALYSIS=MODESDISP=ALL

SUBCASE 2 $ Frequency Response using FREQ set 13FREQUENCY=13DLOAD=111


SUBCASE 4 $ Random Response referencing FRF from subcases 2 and 3ANALYSIS=RANDOMRANDOM=100


$ Change frequenciesSUBCASE 11 $ Frequency Response using FREQ set 23FREQUENCY=23DLOAD=111





Dynamics

Chapter 3: Acoustics

Exterior acoustics

Modeling exterior acoustics using the finite element method (FEM) has some challenges. Inparticular, a non-reflecting (anechoic) boundary condition is required at the free fluid boundary.

Previously, you could define acoustic absorbers on the free fluid mesh boundary with a characteristicimpedance (density x speed of sound). To prevent reflections with this method, this boundary hadto be several wavelengths from the vibrating source. As a result, these models tended to be large,and perfect absorption was still difficult for a range of frequencies.

Beginning with NX Nastran 11, you can now use the Automatically Matched Layer (AML) to representthe non-reflective acoustic boundary condition. The AML method uses a reflection-less artificial layerthat absorbs outgoing waves regardless of their frequency and angle of incidence. The AML isdefined on a convex shape boundary using the new AMLREG bulk entry. An AML region can bemodeled close to the vibrating structure or acoustic source with good accuracy resulting in muchsmaller finite element (FE) models.

The following example demonstrates how an AML can be specified to represent the radiation froma vibrating gearbox.



Structural Mesh

Fluid Mesh

AML

The AML produces accurate results for the FE domain, yet the FE domain represents a small part ofthe fluid, which in reality is infinite. In addition to the AML, you can also request acoustic results onarbitrary locations exterior or interior to the fluid. For your output requests exterior to the meshedvolume, NX Nastran uses the acoustic results at the boundary of the FE domain and a boundaryintegral to obtain the acoustic response. For your output requests at arbitrary locations interior to themeshed volume, NX Nastran uses a finite element interpolation approach. These exterior and interiorlocations are defined with the new microphone mesh. See Microphone mesh.

The AML can be specified in a direct frequency response solution (SOL 108) or in a modal frequencyresponse solution (SOL 111). When an AML is defined in a modal frequency response solution, thestructure is reduced to modal coordinates, although the acoustic fluid remains in physical coordinates.

For detailed information on the AML, see the Acoustics User’s Guide.



Acoustics

AMLREG

Automatically Matched Layer (AML) Region Definition

Defines automatically matched layer region for acoustic analysis.FORMAT:

1 2 3 4 5 6 7 8 9 10

AMLREG RID SID Name/Descriptor

NL RADSURF INFID1 INFID2 INFID3

EXAMPLE:

AMLREG 1 10 AML REGION 1

7 AML 12 13 14

FIELDS:

Field Contents

RID AML region identification number. (Integer > 0) See Remark 1.

SID Surface identification number. (Integer > 0) See Remark 2.

Name/

Descriptor

The Name/Descriptor is an optional character string. (Character; 48characters maximum; See Bulk Data Syntax Rules) See Remark 3.

NL Number of layers of extrusion to be formed by solver. (Integer > 0;Default = 5)

RADSURF Radiation surface type. (Character; Default = AML)

If RADSURF = AML, the pressure and velocities on the AML boundaryare used to compute results in the far field.

If RADSURF = PHYB, the pressure and velocities on the physicalboundary (that is, all free fluid faces with the exception of faces on theAML and the infinite planes) are used to compute results in the far field.

If RADSURF = NONE, the region does not radiate.

INFIDi Identification number of an infinite plane. Up to three (3) infinite planesare considered for an AML region. The infinite planes are used whenacoustic results are to be computed exterior to the AML region. (Integer≥ 0; Default = 0) See Remark 4.

REMARKS:1. RID must be unique with respect to all other AMLREG bulk entries. AMLREG

definitions are only valid for analyses with AML method.

2. The SID references a BSURFS bulk entry to define the fluid element faces used todescribe the AML region. The element faces on the BSURFS entry must all beon fluid elements.


Acoustics


3. Because of the name/descriptor field, free-field and large field data formats are notsupported for this bulk entry.

4. If INFIDi = 0, there is no infinite plane for this AML region. If INFIDi > 0, INFIDireferences an IPLANE bulk entry to define the infinite plane. If infinite planes exist,then every AML region free edge must belong to an infinite plane. Each and everyAML region free edge must belong to one and only one infinite plane. No otherelement edges in the AML region except free edges can belong to an infinite plane.

Microphone mesh

Microphone mesh

Beginning with NX Nastran 11, you can request acoustic results on arbitrary locations exterior orinterior to the fluid. These locations are defined with the new 0D, 1D, 2D, or 3D microphone mesh. Amicrophone mesh is also known as a field point mesh.

Microphones locations can be as follows:

• Exterior to the convex AML boundary.

• Interior to the convex AML boundary.

• On the convex AML boundary.

When a microphone mesh is interior or on the AML boundary, NX Nastran interpolates the resultsfrom the fluid grids to the microphone location. However, when the microphone mesh is exterior tothe AML boundary, NX Nastran uses the pressure and velocity on the AML (or optionally on thephysical boundary if requested), and a boundary integral, to compute the results at the exteriormicrophone locations.

You can request pressure output with the PRESSURE case control command, acoustic intensitywith the ACINTENSITY case control command, and acoustic velocity with the ACVELOCITY casecontrol command for the fluid grids referenced by a 0D, 1D, 2D, and 3D microphone mesh. Youcan also request acoustic power for the fluid grids referenced by a 2D microphone mesh with theACPOWER case control command.

The following summarizes the 0D, 1D, 2D, and 3D microphone mesh definitions on fluid grid points:

• You can specify the 0D microphone mesh using the MICPNT bulk data entry.

• You can specify the 1D microphone mesh using the CROD entry which references the PMICbulk entry for the physical property.

• You can specify the 2D microphone mesh using the CTRIA3 and CQUAD4 entries whichreference the PMIC bulk entry for the physical property.

• You can specify the 3D microphone mesh using the CTETRA, CHEXA, CPENTA, and CPYRAMentries which reference the PMIC bulk entry for the physical property.

The following example demonstrates a 2D microphone mesh.



Acoustics

2D microphone mesh

Infinite planes

Acoustic results for microphone meshes exterior to the AML region are derived using boundaryintegrals. You can define additional boundaries called infinite planes exterior to AML region in orderto influence the derived acoustic results.

The planes are created with the new IPLANE bulk entry which includes the TYPE field to designatethem as a zero velocity or a zero pressure acoustic reflection boundary. You then select up tothree infinite planes with the AMLREG entry. If you select multiple infinite planes, they must beperpendicular to one another.

• An infinite plane with TYPE=0 defines a rigid, reflective boundary in which the velocity is zero.This is also known as a symmetric acoustic boundary. For example, air-to-ground is a zerovelocity reflective boundary.

• An infinite plane with TYPE=1 defines a pressure release reflective boundary in which thepressure is zero. This is also known as an anti-symmetric acoustic boundary. For example,air-to-water is a zero pressure reflective boundary.

You should only define a microphone mesh on the side of an infinite plane in which the fluid elementsare defined. The software will not compute results on the non-fluid side.

Location of pressure and pressure gradients

You can use the RADSURF field on the AMLREG entry to select the location of pressure and pressuregradients for computing the acoustic results on microphone locations exterior to the AML region.


Acoustics


• When RADSURF = AML, the pressure and pressure gradients at the AML are used to computethe results exterior to the AML region.

• When RADSURF = PHYB, the pressure and pressure gradients on the physical boundary areused to compute the results exterior to the AML region. The physical boundary is defined as allfluid free faces excluding those on the AML and those on an infinite plane.

The following examples illustrate the use of AML, RADSURF, and infinite plane:

Structural Mesh (grey)

Fluid Mesh (blue)

AML (green)

RADSURF (red)Figure 3-1. RADSURF(red) = AML

Infinite Plane (purple)

Figure 3-2. RADSURF(red) = PHYB



Acoustics

IPLANE

Infinite Plane Definition

Defines infinite plane for acoustic analysis.FORMAT:

1 2 3 4 5 6 7 8 9 10

IPLANE IPID TYPE SID CID CSP

EXAMPLE:

IPLANE 100 20

IPLANE 200 0 10 1

FIELDS:

Field Contents

IPID Identification number of infinite plane. (Integer > 0; No default)

TYPE Type of reflective plane. See Remark 1. (Integer 0 or 1; Default = 0)

0 = symmetric

1 = anti-symmetric

SID Surface region identification number. (Integer ≥ 0; See Remark 2 fordefault behavior)

CID Rectangular coordinate system identification number. (Integer ≥ 0;Default = 0 for basic coordinate system)

CSP Plane of coordinate system. (Integer 1, 2, or 3; No default)

1 = YZ

2 = ZX

3 = XY

REMARKS:1. The TYPE field designates the infinite plane as a zero velocity or a zero pressure

acoustic reflection boundary. You can select up to three infinite planes with theAMLREG entry. If you select multiple infinite planes, they must be perpendicular toone another.

• When TYPE = 0, the infinite plane is a rigid, reflective boundary in which thevelocity is zero. This is also known as a symmetric acoustic boundary. Forexample, air-to-ground is a zero velocity reflective boundary.

• When TYPE = 1, the infinite plane is a pressure release reflective boundary inwhich the pressure is zero. This is also known as an anti-symmetric acousticboundary. For example, air-to-water is a zero pressure reflective boundary.


Acoustics


2. The infinite plane is defined as follows:

• SID > 0

When SID > 0, the SID references a BSURFS bulk entry containing elementfaces that are used to define the flat infinite plane. The referenced BSURFSentry must contain element faces in a flat plane.

• SID = 0 or blank

When SID = 0 or blank, a rectangular coordinate system defined by the CIDand CSP fields is used to define the flat infinite plane.

If SID > 0, and the CID and CSP fields are specified, the SID specification takesprecedence.

3. The AML region defined by the AMLREG bulk entry (that references this IPLANEentry) must not protrude through the infinite plane.



Acoustics

ACINTENSITY

Acoustic Intensity Output

Acoustic intensity output request at microphone points (SORT1 format only).

FORMAT:

EXAMPLES:SET 123=5,10,15,25

ACINTENSITY=123

SET 5=6,8,11

ACINTENSITY(PRINT,PUNCH,PHASE)=5

DESCRIBERS:

Describer Meaning

PRINT The print file (.f06) will be the output medium. (Character; Default= PRINT)

PUNCH The standard punch file (.pch) will be the output medium.

NOPRINT Generates, but does not print intensity results.

REAL or IMAG Requests rectangular format (real and imaginary) of complexoutput. Use of either REAL or IMAG yields the same output.(Character; Default = REAL or IMAG)

PHASE Requests polar format (magnitude and phase) of complex output.Phase output is in degrees.

n ID of SET case control command containing the list ofidentification numbers of fluid grids referenced by microphoneelements at which to calculate acoustic intensity results. (Integer> 0)

ALL Requests acoustic intensity results for all microphone elementsin the model.

NONE Turns this output request off; useful for controlling output requestsacross subcases.

REMARKS:1. Both PRINT and PUNCH may be requested.


Acoustics


2. Acoustic intensity results will be written to the op2 file, if the value of PARAM,POST is -1 or -2.



Acoustics

ACPOWER

Acoustic Power Output

Acoustic power output request for the AMLREGs or 2D microphone elements (SORT2results only).

FORMAT:

EXAMPLES:SET 123=3,6,9

ACPOWER(AMLREG)=123

SET 5=5,10

ACPOWER(GROUP=5,PRINT,PUNCH,PHASE)

DESCRIBERS:

Describer Meaning

ALL Acoustic power for all AMLREGs. (Character; Default = ALL)

NONE No acoustic power for any AMLREGs.

na ID of SET case control command containing the list of setidentification numbers of AMLREG bulk entries at which tocalculate results for the radiating surface. (Integer>0)

ng ID of SET case control command containing the list of setidentification numbers of GROUP bulk entries at which tocalculate results for the radiating surface. (Integer > 0) SeeRemark 2.



NOPRINT Generates, but does not print, acoustic power results.


Acoustics


Describer Meaning



YES Enables acoustic power output. (Character; Default = YES)

NO Disables acoustic power output.


2. Only 2D microphone elements referenced in a GROUP bulk entry will beprocessed for acoustic power results. These elements must reference a PMICproperty. Any other entity contained in a GROUP referenced by this case controlcommand will be ignored.

3. Acoustic power results will be written to the op2 file, if the value of PARAM, POSTis -1 or -2.



Acoustics

ACVELOCITY

Acoustic Velocity Output

Acoustic velocity output request at microphone points (SORT1 format only).

FORMAT:

EXAMPLES:SET 123=5,10,15,25

ACVELOCITY=123

SET 5=6,8,11

ACVELOCITY(PRINT,PUNCH,PHASE)=5

DESCRIBERS:

Describer Meaning



NOPRINT Generates, but does not print, acoustic velocity.



n ID of SET case control command containing the list ofidentification numbers of fluid grids referenced by microphoneelements at which to calculate acoustic velocity results. (Integer> 0)

ALL Request acoustic velocity results for all microphone elementsin the model.

NONE Turns this output request off; useful for controlling output requestsacross subcases.



Acoustics


2. Output will be in SORT1 format.

3. Acoustic velocity results will be written to the op2 file, if the value of PARAM,POST is -1 or -2.



Acoustics

MICPNT

Microphone Point Definition

Defines microphone point for acoustic analysis.FORMAT:

1 2 3 4 5 6 7 8 9 10

MICPNT EID GID Name/Descriptor

EXAMPLE:

MICPNT 100 246 Microphone point 100 on fluid grid 246.

FIELDS:

Field Contents

EID Element ID number for microphone point. (Integer > 0) See Remark 1.

GID Fluid point grid identification number. (Integer > 0) See Remark 2.

Name/

Descriptor

The Name/Descriptor is an optional character string. (Character; 48characters maximum; See Bulk Data Syntax Rules.) See Remark 3.

REMARKS:1. A MICPNT is a 0D microphone element.

2. The GRID bulk entries referenced must be fluid point grids, which are designatedon the GRID bulk entry by CD = -1.

3. Because of the name/descriptor field, free-field and large field data formats are notsupported for this bulk entry.


Acoustics


PMIC

Dummy Property for Microphone Elements

Defines dummy property for microphone elements for acoustic analysis.

FORMAT:

1 2 3 4 5 6 7 8 9 10

PMIC ID

EXAMPLE:

PMIC 1

FIELDS:

Field Contents

ID Microphone element property identification number. (Integer > 0) SeeRemark 1.

REMARKS:1. ID is referenced by the PID of elements to designate them as microphone

elements. The allowable element types are CROD, CTRIA3, CQUAD4, CHEXA,CPENTA, CTETRA, and CPYRAM. PMIC entries must have unique identificationnumbers with respect to all other property entries.

Modal and panel contributionsYou can now use the MODCON and PANCON commands to request contribution results at fluid gridsthat are referenced by the new microphone elements. See Microphone mesh.

Support for one-way acoustic couplingNX Nastran now allows you to neglect the effect of the fluid on the structure. This is known asone-way or weak acoustic coupling.

With the one-way acoustic coupling, the equations for the structure and the fluid DOFs arede-coupled. Instead of a single frequency response solution involving both the structure and the fluidDOFs, NX Nastran internally performs two frequency response solutions. The equations representingthe structural DOFs are solved first followed by the equations representing the fluid DOFs. Thetwo-step solution can reduce the total elapsed time for frequency response solutions significantlysince the total number of DOFs in each step is greatly reduced.

You can specify the one-way coupling with the new CTYPE parameter on the ACMODL bulk dataentry.



Acoustics

ACMODL

Fluid-Structure Interface Modeling Parameters

Defines modeling parameters for the interface between the fluid and the structure.FORMAT:

1 2 3 4 5 6 7 8 9 10

ACMODL INFOR FSET SSET NORMAL OVLPANG SRCHUNIT

INTOL AREAOP CTYPE

EXAMPLE:

ACMODL 0.25 15.0

WEAK

FIELDS:

Field Contents

INFOR Defines the meaning of the SID entered on the FSET and SSET fields.(Character; ELEMENTS, PID or SET3) See Remark 3.

FSET Selects the ID of a SET1 or SET3 entry to define the fluid elements forthe interface. (Integer or blank) See Remark 3.

If the ID is entered, the corresponding fluid elements are considered.

If a negative sign is included in front of the ID, the corresponding fluidelements are excluded.

If blank, all fluid elements are considered.

SSET Selects the ID of a SET1 or SET3 entry to define the structuralelements for the interface. (Integer or blank) See Remark 3.

If the ID is entered, the corresponding structural elements areconsidered.

If a negative sign is included in front of the ID, the correspondingstructural elements are excluded.

If blank, all structural elements are considered.

NORMAL Outward normal search distance to detect fluid-structure interface.(Real > 0.0; Default = 0.5) See Remark 4.

If SRCHUNIT = REL, then NORMAL is a ratio of the height of thefluid box in the outward normal direction to the fluid surface to themaximum edge length of the fluid free face.

If SRCHUNIT = ABS, then NORMAL is the outward search distance inthe model/absolute units.


Acoustics


Field Contents

OVLPANG Angular tolerance in degrees used to decide whether a fluid free faceand a structural face can be considered as overlapping. If the anglebetween the normals of the fluid and structural faces exceeds thisvalue, they cannot be coupled. (Real > 0.0; Default = 60.0)

SRCHUNIT Search units. (Character; Default = REL) See Remark 4.

If SRCHUNIT = ABS, then the model units are absolute.

If SRCHUNIT = REL, then the relative model units are based onelement size.

INTOL Inward normal search distance to detect fluid-structure interface.(Real > 0.0; Default = 0.20) See Remark 4.

If SRCHUNIT = REL, then INTOL is a ratio of the height of the fluidbox in the inward normal direction to the fluid surface to the maximumedge length of the fluid free face.

If SRCHUNIT = ABS, then INTOL is the inward search distance inthe model/absolute units.

AREAOP Alternative fluid-structure coupling method selection. (Integer;Default=0) See Remark 5.

0 = The recommended method is used.

1 = The RBE3 method is used.

CTYPE Fluid-structure coupling type (only supported by new acoustics methodintroduced in NX Nastran 11). (Character; Default = STRONG) SeeRemark 6.

If CTYPE = STRONG, two-way coupling is turned on.

If CTYPE = WEAK, one-way coupling is turned on. Here, the effect ofthe fluid on the structure is assumed to be negligible.

REMARKS:1. Only one ACMODL entry is allowed. If this entry is not present, defaults will be

used.

2. The ACMODL entry is supported in solutions 103, 107-112, and 200.

3. If you enter the IDs of SET1 entries on the FSET and SSET fields, you must entereither ELEMENTS or PID on the INFOR field to define how the software shouldinterpret the items selected by the SET1 entries.

If you enter the IDs of SET3 entries on the FSET and SSET fields, you must enterSET3 on the INFOR field. The TYPE field on the SET3 entries defines how thesoftware should interpret the items selected by the SET3 entries.



Acoustics

The SET1 entry can list element IDs or physical property IDs. The SET3 entry canlist element IDs, physical property IDs, or grid IDs. If property IDs or grid IDsare selected, the software will determine the associated elements. The PSOLIDproperty ID is supported for selecting fluid elements. The PSOLID, PSHELL,PCOMP, and PCOMPG property IDs are supported for selecting structuralelements. Solid composite elements using the PCOMPS property cannot becoupled to the fluid.

4. The fields NORMAL and INTOL are interpreted as follows:

If SRCHUNIT = REL, then NORMAL is a ratio of the outward height of thebounding box to the maximum edge length of the fluid free face. That is, if L isthe largest edge of the fluid free face, the height H of the bounding box used tosearch for structural faces will be NORMAL * L. INTOL applies similarly, but theinward direction.

If SRCHUNIT = ABS, then NORMAL defines the outward height of the fluidbounding box in the model/absolute units. INTOL defines the inward height of thefluid bounding box in the model/absolute units.

If SRCHUNIT = ABS and NORMAL or INTOL are blank, then SRCHUNIT will bereset to REL and their corresponding default value is used.

5. AREAOP = 0 selects the default, recommended NX Nastran coupling option.

AREAOP = 1 selects an alternate option, which applies an area correction andremoves parallel disconnected faces from the coupling.

6. The two-way coupled formulation (that is CTYPE = STRONG) of NX Nastranleads to the following:

where s indicates structure

and f indicates fluid

For a one-way (fully decoupled) solution (that is CTYPE = WEAK), the A term isignored and the formulation becomes:

Acoustic coupling dataWith NX Nastran 11, the SKINOUT describer on the FLSCNT case control command can now writecoupling data to the new OACCQ data block in the op2 file. This contains distance information forthe coupled and uncoupled fluid and structure faces. The new output is in addition to the couplinginformation written to the .dat and .pch files.


Acoustics


You can use this information to display the coupling data as follows. The example displays coupledand uncoupled structural faces.

UncoupledStructural Faces(red)

CoupledStructural Faces(blue)

For detailed information on the new OACCQ data block, see the DMAP Programmer's Guide andthe Acoustics User's Guide



Acoustics

FLSTCNT

Control Parameters for Fluid-Structure Interaction

Miscellaneous control parameters for fluid-structure interaction.FORMAT:

EXAMPLES:FLSTCNT ACOUT=RMS PREFDB=1.0E-06

DESCRIBERS:

Describer Meaning

ACSYM Requests the symmetric solution for fluid structure analysis,when YES. When NO, non-symmetric solution is requested.(Character; Default = YES)

ACOUT PEAK or RMS output with the FORCE Case Control request.(Character; Default = PEAK)

ASCOUP Requests a fluid-structure coupled solution when YES. WhenNO, the fluid and the structure are decoupled (Character; Default= YES)

PREFDB Specifies the reference pressure. (Real; Default = 1.0)


Acoustics


Describer Meaning

SKINOUT Specifies if coupling data with the pairing information is output.

SKINOUT=FREEFACE writes coupling data to a .dat and punchfiles, and writes the coupling datablock to the .op2 file. Thesolution proceeds after the data is written. Both coupled anduncoupled faces are written.

SKINOUT=STOP works like SKINOUT=FREEFACE, but thesolution stops immediately after the debug files are created.

SKINOUT=PUNCH writes coupling data to .dat and punch files.The solution proceeds after the data is written. It will not writethe coupling datablock to the .op2 file. Only coupled free facesare written.

SKINOUT=NONE does not output coupling data. (Character;Default = NONE)

AGGPCH Requests the output of the fluid-structure coupling matrix AGG tothe punch file when YES. When NO, the coupling matrix is notwritten. (Character; Default = NO)

SFEF70 Requests the import of a fluid-structure coupling matrix createdby SFE AKUSMOD when YES. When NO, the coupling matrix isnot imported. (Character; Default = NO)

NONE No debug deck or pairing information is generated.

PUNCH Debug pairing information file is created. The name of the fileswill be the base name of the deck appended with “_acdbg.dat”and “_acdbg.pch”.

FREEFACE All free faces are written into a debug file.

STOP The run is terminated as soon as the debug file with pairinginformation is created.

REMARKS:1. All the entries specified in this case control statement are available as

PARAMETER statements.

2. The coupling data files output by the SKINOUT describer include dummy shellelements. The PSHELL IDs referenced be these elements have the followingmeaning.

• Shell elements representing the coupled structural free faces referencePSHELL ID = 1.

• Shell elements representing the coupled fluid free faces reference PSHELL ID= 2.



Acoustics

• Shell elements representing the uncoupled structural free faces referencePSHELL ID = 3.

• Shell elements representing the uncoupled fluid free faces reference PSHELLID = 4.

3. If SFEF70 = YES, NX Nastran does not compute the coupling, and instead usesthe SFE AKUSMOD coupling definition from the external file. NX Nastran expectsthe AKUSMOD file in the same directory where the job is being run, and expectsthe file name to be fort.70. An ASSIGN statement that uses UNIT=70 must bedefined in the file management section of your input file if the coupling file is notnamed fort.70 or if it is in a location other than where the job is run. For example,

ASSIGN OUTPUT2=’/directory_path/user_file_name.70’ UNIT=70

Adding pre-computed enforced vibrations at fluid-structure interfaceWhen surface vibrations (displacement, velocity, or acceleration) on the structure are known anddefined as an input excitation, you may only need the structural DOFs in order to enforce this loadingto the acoustic mesh.

You can now set the new SPCSTR parameter to YES to constrain the structural DOFs in the analysisset, but only after the structural excitation is transferred over to the fluid.

See the SPCSTR parameter in the NX Nastran Quick Reference Guide.

Support for porous materialsBeginning with NX Nastran 11, you can use the new MATPOR bulk entry for modeling a rigid porousor a limp porous acoustic absorber material.

With the MATPOR bulk entry, you can select the "Craggs", the "Delaney-Bazely/Miki", or the"Johnson-Champoux-Allard" empirical model and enter the relevant parameters. You can useMATPOR bulk entries in combination with CHEXA, CPENTA, CPYRAM, and CTETRA elements whenthese elements reference PSOLID property bulk entries that have the FCTN field set to PFLUID.

For more information on the empirical models, see the Acoustics User’s Guide. For more informationon MATPOR bulk entry, see the MATPOR bulk entry in the Quick Reference Guide.


Acoustics


MATPOR

Porous Material Property Definition

Defines material properties for porous materials used as acoustic absorbers.FORMAT FOR

CRAGGSMODEL

(MODEL =“CRAGGS”):

1 2 3 4 5 6 7 8 9 10MATPOR MID MODEL RHO C

RES POR TORT

FORMAT FORDELANEY-MIKI

MODEL(MODEL =

“DELMIKI”):

1 2 3 4 5 6 7 8 9 10MATPOR MID MODEL RHO C FRAME

RES POR DENS

FORMAT FORJOHNSON-CHAMPOUX-ALLARD

MODEL(MODEL =

“JCA”):

1 2 3 4 5 6 7 8 9 10MATPOR MID MODEL RHO C FRAME GAMMA PR MU

RES POR TORT DENS L1 L2

EXAMPLES:

MATPOR 20 CRAGGS 1.225E-9 340000.087000.0 0.97 2.52

MATPOR 20 DELMIKI 1.225E-9 340000.0 LIMP87000.0 0.97 31.0E-9

MATPOR 20 JCA 1.225E-9 340000.0 LIMP 1.4 0.71 1.84E-587000.0 0.97 2.52 31.0E-9 0.037 0.119

FIELDS:

Field Contents

MID Material identification number. (Integer > 0)



Acoustics

Field Contents

MODEL Porous material model. (Character; No default) See Remark 2.

“CRAGGS” for the Craggs model.

“DELMIKI” for the Delany-Miki model.

“JCA” for the Johnson-Champoux-Allard model.

RHO Density of the fluid. (Real; Default = 0.0)

C Speed of sound in the fluid. (Real; Default = 0.0)

FRAME Compliance of solid. (Character; No default)

“RIGID” for a rigid solid.

“LIMP” for an extremely soft solid.

GAMMA Ratio of constant pressure specific heat to constant volumespecific heat. (Real ; Default = 0.0)

PR Prandtl number. (Real; Default = 0.0)

MU Dynamic viscosity. (Real; Default = 0.0)

RES Flow resistivity. (Real; Default = 0.0)

POR Porosity. (Real; Default = 0.0)

TORT Tortuosity. (Real; Default = 0.0)

DENS Density of the frame. (Real; Default = 0.0)

L1 Characteristic viscous length. (Real; Default = 0.0)

L2 Characteristic thermal length. (Real; Default = 0.0)

REMARKS:1. MATPOR bulk entries can only be referenced by PSOLID bulk data entries and

associated with CHEXA, CPENTA, CPYRAM, and CTETRA bulk data entries.

2. For a detailed explanation of each material model, see the Acoustics User's Guide.

System cell to revert acoustic behaviorSystem cell 617 (ACFORM) is available to revert to the previous acoustics behavior.

= 1 (default) Selects the current acoustics behavior which includes AML and porous materials.

= 0 Reverts to the NX Nastran 10 acoustics behavior.


Acoustics


New Acoustics User's GuideBeginning with NX Nastran 11, an Acoustics User's Guide is now available. The information whichwas in the NX Nastran User's Guide and Advanced Dynamic Analysis User's Guide has beenconsolidated into the new Acoustics User's Guide.

The Acoustics User's Guide covers a great deal of acoustic theory and also includes explanations ofkey modeling aspects in the Acoustic analysis using automatically matched layer chapter.



Chapter 4: Rotor dynamics

Mode filteringBeginning with NX Nastran 11, you can use strain energy-based criteria and kinetic energy-basedcriteria to identify the modes that have minimal impact on the dynamic response in a SOL 107 orSOL 110 complex eigenvalue analysis in rotor dynamics. You can omit these modes from the list ofmodes that are tracked throughout the remainder of the rotor dynamics analysis. Because modes oflittle importance are eliminated, the analysis results produce a less cluttered and potentially moremeaningful Campbell diagram.

To determine the importance of modes, you can use either or both of the following criteria:

• The ratio of the strain energy of a specific rotor to the total strain energy of the system fora given mode.

• The ratio of the kinetic energy of a specific rotor to the total kinetic energy of the system fora given mode.

To identify the modes which contribute little to the dynamic response, use the new ROTPARM bulkentry. With the ROTPARM bulk entry, you specify:

• The energy-based criterion for the software to use.

• The threshold value for the criterion below which modes are deemed of little importance tothe dynamic response.

If you specify the option that uses both criteria, only modes whose ratios fall below the thresholdfor both criteria are deemed of little importance.

• The reference rotor. The reference rotor is the rotor whose strain or kinetic energy is used tocalculate the ratio of energy of the rotor to the total energy of the system.

You specify the reference rotor in the REFROT field of the ROTPARM bulk entry.

Caution

For meaningful results, on the ROTORD bulk entry, set the RSPEEDi field for thereference rotor to 1.0. The software does not trap other values.

In the results file, the important modes are denoted by “***” in the summary line. The modes oflittle importance are not denoted in any way.

To omit the modes that are deemed of little importance, in the input file, include PARAM,MODTRK,4.The software does not omit modes if you specify any other mode tracking option or no mode trackingoption. Modes are also not omitted if you specify PARAM,MODTRK,4, but do not specify one of theenergy-based criteria on the ROTPARM bulk entry.



The MODTRK = 4 option uses the modes for the reference rotor at the initial non-zero speed as thebase vectors for the complex eigenvalue calculations at subsequent rotor speeds. This approachimproves the quality of the mode tracking and reduces the computational time for complex modecalculations.

For more information, see the new ROTPARM bulk entry and the updated MODTRK parameter.



Rotor dynamics

ROTPARM

Parameter Specification for Rotor Dynamic Analysis

Defines solution control parameters for frequency response and complex eigenvaluerotor dynamic analysis.

FORMAT:

1 2 3 4 5 6 7 8 9 10ROTPARM SID PARAM1 VALUE1 PARAM2 VALUE2 PARAM3 VALUE3

PARAM4 VALUE4 PARAM5 VALUE5 -etc-

EXAMPLE:

ROTPARM 1 SEFILT YES SETHRSH 20.0 KETHRSH 15.0

REFROT 1

FIELDS:

Field Contents

SID Set identification number. See Remark 1. (Integer > 0)

PARAMi Parameter name. Allowable names are given in the parameter listingbelow. (Character)

VALUEi Value of the parameter. (Real, Integer, or Character)

ROTPARMPARAMETERS:

Name Description

ROTSEKE Print energy calculations. (Character “YES” or “NO”; Default = “NO”)

REFROT Identification number (RIDi on the ROTORD bulk entry) of thereference rotor. The reference rotor is used as the rotor whose strainor kinetic energy is used in the calculation of ratio of energy of therotor to total energy of the system, and is used as the reference rotorfor rotor speed calculations. See Remark 2. (Integer > 0; For defaultbehavior, see Remark 3)

SEFILT Identify modes that have a ratio of strain energy of the reference rotorto total strain energy of the system that exceeds the strain energythreshold value. See Remarks 4, 5, and 6. (Character “YES” or “NO”;Default = “NO”)


Rotor dynamics


Name Description

KEFILT Identify modes that have a ratio of kinetic energy of the referencerotor to total kinetic energy of the system that exceeds the kineticenergy threshold value. See Remarks 4, 5, and 6. (Character “YES”or “NO”; Default = “NO”)

SETHRSH Strain energy threshold value in percent. (Real > 0.0; Default = 30.0)

KETHRSH Kinetic energy threshold value in percent. (Real > 0.0; Default = 30.0)

REMARKS:1. The SID of the ROTPARM bulk entry must be the same as the SID of the

ROTORD bulk entry.

2. If the REFROT field is not specified, to obtain meaningful results, on the ROTORDbulk entry, the RSPEEDi field for the reference rotor must be set to 1.0. Thesoftware does not trap other values.

3. For a system with a single rotor, the single rotor is the default reference rotorfor the energy calculations in complex eigenvalues. For a system with multiplerotors, there is no default reference rotor.

4. If only SEFILT is specified, modes that pass the SEFILT criterion are identified by“***” in the summary line of the results. If only KEFILT is specified, modes that passthe KEFILT criterion are identified by “***” in the summary line of the results. If bothSEFILT and KEFILT are specified, modes that pass either the SEFILT criterion orKEFILT criterion are identified by “***” in the summary line of the results.

5. When either or both SEFILT and KEFILT are specified, and MODTRK = 4 isspecified, only the modes identified by “***” in the summary line of the results aretracked for use in a Campbell diagram.

6. Energy-based filtering of modes is valid for SOL 107 and SOL 110 complexeigenvalue rotor dynamic analysis only.

MODTRK

Default = 2

This parameter is used in a rotor dynamics solution to select the mode tracking method.

If MODTRK = 1, the pre-NX Nastran 7 method is used. Outer loop over rotor speed, inner loop overdegrees of freedom. This method does not work well for the direct method (SOL 107) because there,new solutions can come in and old solutions can leave the solution space.

If MODTRK = 2, the method introduced in NX Nastran 7 is used. Outer loop over degrees of freedom,inner loop over rotor speed. Process is repeated until all solutions have been tracked.

If MODTRK = 3, the method introduced in NX Nastran 8.5 is used. Eigenvectors and eigenvalues areused to track the modes. This method is applicable to models having any combination of unsymmetricstiffness, unsymmetric viscous damping, and structural damping.



Rotor dynamics

If MODTRK = 4, the method introduced in NX Nastran 11 is used. The initial reference rotor modesare used as the base vectors for complex eigenvalue calculations at subsequent reference rotorspeeds. Mode tracking begins at the first nonzero reference rotor speed. Modes for the referencerotor speed of zero are excluded from the Campbell diagram results.

The following parameters apply if MODTRK = 2: MTREPSI, MTREPSR, MTRFCTD, MTRFCTV,MTRFMAX, MTRRMAX, and MTRSKIP.

The following parameters apply if MODTRK = 3: MTRFMAX and MTRRMAX.

If the tolerances MTREPSR and MTREPSI are chosen too small, the solution may be lost for somespeed values. If the tolerance is too large, there may be lines crossing from one solution to another.Problems may occur for turbines with many elastic blades with equal frequencies. Then clusters oflines and crossings may occur.

Complex eigenvalue and frequency response analysis enhancementsFor frequency response and complex eigenvalue rotor dynamic analysis, you can now do thefollowing:

• You can include gyroscopic and circulation terms in the mass, damping, and stiffness matriceswhen the analysis is performed in the fixed reference system by specifying the new RLOOPNEWparameter.

• You can list a rotor in the REFROT field of the ROTPARM bulk entry to designate it as thereference rotor.

Gyroscopic and circulation term scaling

The combined rotor mass, damping, and stiffness contributions, including gyroscopic and circulationterms, are shown below for both frequency response and complex eigenvalue analysis.

• Frequency response analysis:

• Asynchronous complex eigenvalue analysis (Ωref = constant):


Rotor dynamics


• Synchronous complex eigenvalue analysis (Ωref = ω):

In the equations, the following nomenclature is used:

MjR Mass of the jth rotor

BjR Viscous damping of the jth rotor

KjR Stiffness of the jth rotor

K4jR Hysteretic damping of the jth rotor (GE on MATi bulk entries)

BjG Gyroscopic terms for the jth rotor

KjCB Circulation terms due to viscous damping for the jth rotor

KjCK Circulation terms due to structural damping for the jth rotor (PARAM,G)

KjCK4 Circulation terms due to hysteretic damping for the jth rotor (GE on MATi bulkentries)

G Structural damping value (PARAM,G)

W3j Reference frequency for structural damping in rad/sec for the jth rotor

W4j Reference frequency for hysteretic damping in rad/sec for the jth rotor

ω Excitation frequency in rad/sec

Ωj Speed in rad/sec of the jth rotor

Ωref Speed of the reference rotor in rad/sec

αj Ratio of the speed of the jth rotor to the reference rotor speed (based on theRSTART value on the ROTORD bulk entry)

Reference rotor specification

In versions prior to NX Nastran 11, the reference rotor is not a part of the physical system. It is animaginary construct, and is referred to as the imaginary reference rotor.

Beginning with NX Nastran 11, you can use the ROTPARM bulk entry to designate a rotor in thephysical system as the reference rotor. To do so, list the rotor in the REFROT field of the ROTPARM



Rotor dynamics

bulk entry. The software then uses the RSPEEDi field specifications on the ROTORD bulk entry tocalculate the speed ratios and speeds for the other rotors in the physical system.

To have the software use the pre-NX Nastran 11 approach to calculating rotor speeds, specifyPARAM,RLOOPNEW,NO (the default) and leave the REFROT field blank on the ROTPARM bulkentry.

The following examples demonstrate how the software calculates rotor speeds when you include avalue in the REFROT field of the ROTPARM bulk entry.

• Fixed rotor speed ratios

For this case, you specify real values in the RSPEEDi fields of the ROTORD bulk entry. Thesoftware determines the rotor speed ratios by setting the speed ratio for the rotor listed in theREFROT field of the ROTPARM bulk entry to 1.0 and calculating the speed ratios for the otherrotors from the RSPEEDi values.

For example, suppose that in a two rotor model, RSPEED1 = 2.0 and RSPEED2 = 3.0. If youspecify rotor 1 in the REFROT field of the ROTPARM bulk entry, the software sets the speed ratiofor rotor 1 to 1.0 and calculates the speed ratio for rotor 2 to be 1.5 = 3.0 / 2.0. The software thencalculates the speed of rotor 2 to be the product of 1.5 and the speed of rotor 1.

If you specify rotor 2 as the reference rotor, the software sets the speed ratio for rotor 2 to 1.0 andcalculates the speed ratio for rotor 1 to be 0.6667 = 2.0 / 3.0. The software then calculates thespeed of rotor 1 to be the product of 0.667 and the speed of rotor 2.

• Table of rotor speed ratios vs. reference rotor speed

For this case, you specify integer values in the RSPEEDi fields of the ROTORD bulk entrythat reference TABLEDi bulk entries. On the TABLEDi bulk entries, you define how the speedratio between the rotor and the imaginary reference rotor varies as a function of the imaginaryreference rotor speed.

The procedure the software uses to calculate the rotor speed ratios is best demonstrated in anexample.

Suppose that in a two rotor model, the speed ratio as a function of the imaginary referencerotor speed for rotor 1 is given by

TABLED1, 1,, 0.0, 0.0, 1000.0, 2.0, 2000.0, 2.5, ENDT

The speed ratio as a function of the imaginary reference rotor speed for rotor 2 is given byTABLED1, 2,, 0.0, 0.0, 500.0, 2.0, 3000.0, 3.0, ENDT

Also suppose that rotor 1 is specified in the REFROT field of the ROTPARM bulk entry.

The software begins by creating a table of rotor speed for the rotor specified in the REFROT fieldvs. imaginary reference rotor speed. Using the TABLED1 bulk entry for rotor 1, the table isas follows:

REFROT rotor Imaginary reference rotor0.0 0.02000.0 = 2.0 x 1000.0 1000.05000.0 = 2.5 x 2000.0 2000.0


Rotor dynamics


Suppose the software needs the rotor speeds for a reference rotor speed of 1500.0. That is,the speed of the rotor specified in the REFROT field of the ROTPARM bulk entry is 1500.0. Thesoftware interpolates the REFROT rotor vs. imaginary reference rotor tabular data to obtainan imaginary reference rotor speed of 750.0.

To determine the speed ratio for rotor 2 that corresponds to an imaginary reference rotor speed of750.0, the software interpolates the TABLED1 data for rotor 2. Thus, the software calculates thespeed ratio for rotor 2 to be 2.1 = 2.0 + (3.0 - 2.0) [(750.0 - 500.0) / (3000.0 - 500.0)].

Using the interpolated speed ratio for rotor 2 and the imaginary reference rotor speed, thesoftware then calculates the speed of rotor 2 to be 1575.0 = 2.1 x 750.0. Thus, the speed ratio ofrotor 2 relative to the rotor listed in the REFROT field is 1.05 = 1575.0 /1500.0.

• Direct specification of rotor speeds

For this case, you specify:

1. Integer values in the RSPEEDi fields of the ROTORD bulk entry that reference DDVALbulk entries.

2. PARAM, RSPDTYPE, DDVAL

3. DDVAL bulk entries for each rotor in the system.

On each DDVAL bulk entry, you list the speed of the rotor for each spin state of the system.

Note

A spin state is the set of all rotor speeds that occur simultaneously.

When you use this approach, the software interpolates the data on the DDVAL bulk entries todetermine the rotor speeds directly.

For example, suppose that in a three rotor model, the DDVAL bulk entry for rotor 1 is given by

DDVAL, 1, 1000.0, 4000.0

The DDVAL bulk entry for rotor 2 is given by

DDVAL, 2, 2000,0, 6000.0

The DDVAL bulk entry for rotor 3 is given by

DDVAL, 3, 3000,0,12000.0

If rotor 2 is the specified in the REFROT field of the ROTPARM bulk entry and the analysis isto be performed with the speed of rotor 2 at 4000.0, the corresponding speed for rotor 1 is2500.0 = 1000.0 + (4000.0 - 1000.0) / 2, and the corresponding speed for rotor 3 is 7500.0= 3000.0 + (12000.0 - 3000.0) / 2.

You can use fixed rotor speed ratios and tables of rotor speed ratios vs. reference rotor speed incombination. However, if you use the DDVAL approach, all rotors must reference DDVAL bulk entries.



Rotor dynamics

Note

As a best practice, use the DDVAL approach to define speed ratios that vary.

Load specification options for maneuver load analysisIn earlier versions of NX Nastran, your only options for specifying the inertial loads that result fromangular motion in a SOL 101 maneuver load analysis were the RFORCE and RFORCE1 bulk entries.The only difference between them is that RFORCE applies the loading to the entire model andRFORCE1 applies the loading to a subset of the model that is defined by a GROUP bulk entry.

With NX Nastran 11, the new RFORCE2 bulk entry gives you a third option. The RFORCE2 bulkentry is similar to the RFORCE entry in that it applies the loading to the entire model. However, itdiffers from RFORCE in that you can optionally exclude either the gyroscopic or centrifugal forcesthat result from the angular motion of the model. To exclude these forces from the loading, specify theappropriate value in the GYROP field of the RFORCE2 bulk entry.

For more information, see the new RFORCE2 bulk entry.


Rotor dynamics


RFORCE2

Rotational Force for SOL 101 Rotor Dynamic Analysis

Defines a static loading condition due to an angular velocity and/or angular accelerationfor maneuver load rotor dynamic analysis. Valid for SOL 101 only.

FORMAT:

1 2 3 4 5 6 7 8 9 10

RFORCE2 SID G CID A R1 R2 R3 METHOD

RACC MB GYROP

EXAMPLE:

RFORCE2 2 5 –6.4 0.0 0.0 1.0 2

1.0 1

FIELDS:

Field Contents

SID Load set identification number. (Integer > 0)

G Grid point identification number through which the rotation vector acts.See Remark 5. (Integer ≥ 0; Default = 0)

CID Coordinate system defining the components of the rotation vector.See Remarks 6 and 7. (Integer ≥ 0, Default = 0)

A Scale factor of the angular velocity in revolutions per unit time. (Real;Default = 1.0)

R1, R2, R3 Dimensionless rectangular components of the rotation vector thatpasses through grid point G. (Real; R12 + R22 + R32 > 0.0; DefaultsR1 = 1.0, R2 = 0.0, R3 = 0.0)

METHOD Method used to compute centrifugal forces. See Remarks 8 and 9.(Integer = 1 or 2; Default = 2)

RACC Scale factor of the angular acceleration in revolutions per unit timesquared. (Real; Default = 0.0)

MB Indicates whether the CID coordinate system is defined in the mainBulk Data Section or the partitioned superelement Bulk Data Section.Coordinate systems referenced in the main Bulk Data Section areconsidered stationary with respect to the assembly basic coordinatesystem. See Remark 10. (Integer = –1 or 0; Default = 0)= –1 if the CID coordinate system is defined in the main Bulk DataSection= 0 if the CID coordinate system is defined in the partitionedsuperelement Bulk Data Section



Rotor dynamics

Field Contents

GYROP Force calculation option. (Integer = 0 or 1 or 2; Default = 0)= 0 to include centrifugal and gyroscopic force terms= 1 to include centrifugal force terms only= 2 to include gyroscopic force terms only

REMARKS:1. If RFORCE2 entries are used in any analysis other than a SOL 101 rotor dynamic

analysis, an error message is issued and the run is terminated.

2. In Figure 4-1, the force vector at a grid point Gi is given by:

where [m]i is a 3 × 3 translational mass matrix at grid point Gi.

The angular velocity and angular acceleration vectors are given by:

Angular velocity

Angularacceleration

where A is the angular velocity scale factor, RACC is the angular acceleration

scale factor, and is the dimensionless rotation vector.

The equation for will have additional terms if the mass is offset and METHOD =1 is selected.


Rotor dynamics


Figure 4-1. RFORCE2 Vector at a Grid Point

3. In the static solution sequences, the load set ID (SID) is selected by the CaseControl command LOAD. In the dynamic solution sequences, SID must bereferenced in the LID field of an LSEQ entry, which in turn must be selected bythe Case Control command LOADSET.

4. The load vector generated by this entry can be printed with an OLOAD commandin the Case Control Section.

5. G = 0 (Default) signifies that the rotation vector acts through the origin of thebasic coordinate system.

6. CID = 0 (Default) signifies that the rotation vector is defined in the basic coordinatesystem.

7. If CID is not a rectangular coordinate system, RFORCE2 will treat it as if it wereand unexpected answers may result.

8. METHOD = 1 yields correct results only when there is no coupling in the massmatrix. This occurs when the lumped mass option is used with or without theZOFFS option (see the CQUAD4 entry for a description of ZOFFS). METHOD = 2yields correct results for lumped or consistent mass matrix only if the ZOFFS optionis not used. The acceleration terms due to the mass offset (X1, X2, X3) on theCONM2 entry are not computed with METHOD = 2. All the possible combinationsof mass matrices and offset and the correct method to be used are shown below.

No Offset OffsetLumped METHOD = 1 or METHOD = 2 METHOD = 1Coupled METHOD = 2 Neither



Rotor dynamics

9. Forces due to angular acceleration (RACC) are computed with METHOD = 2 evenif METHOD = 1 is specified.

10. The coordinate systems in the main Bulk Data Section are defined relative to theassembly basic coordinate system which is fixed. This feature is useful when asuperelement defined by a partitioned Bulk Data Section is rotated or mirroredand the gravity load is more conveniently defined in terms of coordinates whichare fixed.

11. For superelement analysis, G should reference a residual structure point that isexterior to all superelements. If it is not exterior to a superelement, then centrifugalloads will not be generated for that superelement. However, in cyclic analysis,User Fatal Message 4347 will be issued.

12. The continuation entry is optional.

13. Loads derived from this entry do not include effects due to mass specified forscalar points.

14. To model angular motion where the angular velocity and angular accelerationvectors have different directions, use two RFORCE2 entries that have the sameSID. Use one entry to define the angular velocity vector, and use the other entry todefine the angular acceleration vector.

Synchronous modes in complex modal solutionsBeginning with NX Nastran 11, you can optionally solve for synchronous modes only in a SOL 107or SOL 110 complex eigenvalue rotor dynamic analysis. To do so, specify NUMSTEP = 0 on theROTORD bulk entry and include PARAM,ROTSYNC,YES (default) in your input file. If you specifyNUMSTEP = 0 and PARAM,ROTSYNC,NO, no analysis is performed.

For more information, see the updated ROTORD bulk entry.


Rotor dynamics


ROTORD

Define Rotor Dynamics Solution Options

Defines rotor dynamics solution options.

FORMAT:

1 2 3 4 5 6 7 8 9 10ROTORD SID RSTART RSTEP NUMSTEP REFSYS CMOUT RUNIT FUNIT

ZSTEIN ORBEPS ROTPRT SYNC ETYPE EORDER THRSHOLD MAXITER

RID1 RSET1 RSPEED1 RCORD1 W3_1 W4_1 RFORCE1 BRGSET1

RID2 RSET2 RSPEED2 RCORD2 W3_2 W4_2 RFORCE2 BRGSET2....

RIDi RSETi RSPEEDi RCORDi W3_i W4_i RFORCEi BRGSETi....

RID10 RSET10 RSPEED10 RCORD10 W3_10 W4_10 RFORCE10 BRGSET10

EXAMPLE:

ROTORD 998 0.0 250.0 58 fix -1.0 cps

no

1 11 1 0.0 0.0 1 101

2 12 1 0.0 0.0 102

3 13 1.5 1 0.0 0.0 103

4 14 1.75 1 0.0 0.0 104

5 15 1.75 1 0.0 0.0 105

6 16 1 0.0 0.0 106

7 17 2.0 1 0.0 0.0 107

8 18 2.25 1 0.0 0.0 108

9 19 7.5 1 0.0 0.0 109

10 20 1 0.0 0.0 10 110

FIELDS:

Field Contents

SID Set identifier for all rotors. Must be selected in the case control deckby RMETHOD = SID. (Integer > 0)

RSTART Starting value of reference rotor speed. See Remark 2 and Remark4. (Real)

RSTEP Step-size of reference rotor speed. See Remark 3. (Real ≠ 0.0)

NUMSTEP Number of steps for reference rotor speed including RSTART. SeeRemark 14. (Integer ≥ 0 for SOLs 107 and 110, Integer > 0 for allother supported SOLs)



Rotor dynamics

Field Contents

REFSYS Reference system. (Character; Default = ‘ROT’)

= ‘FIX’ analysis is performed in the fixed reference system.

= ‘ROT’ analysis is performed in the rotational reference system.

CMOUT Determines the rotor speeds at which eigenvectors are calculatedand output. (Real; Default = 0.0)

= 0.0 no eigenvectors are calculated; no eigenvectors are output; nowhirl directions are output.

> 0.0 eigenvectors are calculated at the specified speed;eigenvectors are output at the specified speed; whirl direction isoutput at the specified speed.

= -1.0 eigenvectors are calculated at all speeds; eigenvectors areoutput at all speeds; whirl directions are output at all speeds.

RUNIT Units used for rotor speed inputs (CMOUT, RSTART and RSTEP),output (units for output list and Campbell diagram output), andspeed-dependent bearing property tables. (Character; Default =‘RPM’)

= ‘RPM’ revolutions per minute.

= ‘CPS’ cycles per second.

= ‘HZ’ cycles per second.

= ‘RAD’ radians per second.

FUNIT Units used for frequency output (Campbell diagram output).(Character; Default = ‘RPM’)

= ‘RPM’ revolutions per minute.

= ‘CPS’ cycles per second.

= ‘HZ’ cycles per second.

= ‘RAD’ radians per second.

ZSTEIN Option to incorporate Steiner’s inertia terms. (Character; Default= 'NO')

= 'YES' Steiner’s inertia terms are included.

= 'NO' Steiner’s inertia terms are not included.

ORBEPS Threshold value for detection of whirl direction. (Real > 0.0; Default= 1.E-6)


Rotor dynamics


Field Contents

ROTPRT Controls .f06 output options. (Integer; Default = 0))

= 0 no print.

= 1 print generalized matrices; print final nonlinear bearing values ateach frequency or time.

= 2 print eigenvalue summary and eigenvectors at each RPM; printintermediate nonlinear bearing values for each iteration.

= 3 combination of 1 & 2.

SYNC Option to select synchronous or asynchronous analysis forfrequency response analysis. (Integer; Default = 1)

= 1 synchronous

= 0 asynchronous

ETYPE Excitation type. (Integer; Default = 1)

= 1 Mass unbalanced. Specify mass unbalance = m x r on DLOADbulk entry and the program will multiply by Ω2.

= 0 Force excitation. Specify force = m x r x Ω2 on DLOAD bulk entry.

EORDER Excitation order. (Real; Default 1.0)

= 1.0 (Default) (modes crossing with 1P line in the fixed system)

= 0.0 Forward whirl (modes crossing with 0P line in the rotatingsystem)

= 2.0 Backward whirl (modes crossing with 2P line in the rotatingsystem)

THRSHOLD Convergence threshold when iterating to determine bearing stiffnessor viscous damping for CBEAR elements that have speed anddisplacement or speed and force dependent stiffness or viscousdamping. See Remark 15. (Real > 0.0; Default = 0.02)

MAXITER Maximum number of iterations to determine bearing stiffnessor viscous damping for CBEAR elements that have speed anddisplacement or speed and force dependent stiffness or viscousdamping. A value of 0 implies that no iterations are performed. SeeRemark 15. (Integer ≥ 0; Default = 10)

RIDi Identification number of rotor i. (Integer > 0 with RID(i+1) > RIDi;Default = i)

RSETi Refers to the RSETID value on the ROTORG, ROTORB, andROTSE bulk entries for rotor RIDi. (Integer > 0 or blank if onlyone rotor)



Rotor dynamics

Field Contents

RSPEEDi Multiplier of reference rotor speed for rotor i. (Real ≠ 0.0 or Integer >0 or blank; Default = 1.0)

If real entry, value of multiplier at all reference rotor speeds.

If integer entry, identification number of a TABLEDi entry thatcontains value of multiplier as a function of reference rotor speed.

RCORDi Identification number of the Cartesian coordinate system whoseZ-axis is the axis of rotation axis for rotor i. (Integer; Default = 0 forbasic coordinate system)

W3_i Reference frequency for structural damping defined by PARAM,Gfor rotor i. (Real; Default = 0.0)

W4_i Reference frequency for structural damping defined by GE for rotori. See Remark 8. (Real; Default = 0.0)

RFORCEi Points to RFORCE, RFORCE1, or RFORCE2 bulk entry for rotor i.(Integer; Default = 0 for no rotational force applied; a rotational forceis required for differential stiffness to be calculated.)

BRGSETi Identification number of a GROUP bulk entry that lists the CBEARelements for the corresponding RIDi. Only the GROUP type ELEMis supported. (Integer ≥ 0 or blank; no default)

REMARKS:1. There is a maximum limit of 10 rotors (i.e. 11 continuation lines).

2. The rotation direction for a rotor depends on the algebraic sign of the numericalvalues for RSTART and RSPEEDi as follows:

RSTART RSPEEDi(1) Direction of rotationfor RIDi(2)

> 0 > 0 Positive> 0 < 0 Negative< 0 > 0 Negative< 0 < 0 Positive

(1)If the RSPEEDi field references a TABLEDi bulk entry, the numerical value thesoftware uses from the TABLEDi lookup.(2)The direction of rotation is defined in accordance with the right-hand rule.Positive indicates rotation about the +Z-axis of the RCORDi coordinate system.Negative indicates rotation about the –Z-axis of the RCORDi coordinate system.

3. A negative value for RSTEP causes the reference rotor speed to algebraicallydecrease. For example, assume RSTEP = –200 rpm. If the current reference rotorspeed is +1200 rpm, the reference rotor speed will be +1000 rpm after one step.After five additional steps the reference rotor speed would be 0 rpm. Addtionalsteps would then cause the reference rotor speed to increase in the oppositerotational direction.


Rotor dynamics


4. When the ROTCOUP parameter is specified and REFSYS = ROT, the equation ofmotion includes time-dependent terms and is solved at discrete azimuth angles.The software can either solve the equation of motion over a range of azimuthangles at a single rotor speed, or solve the equation of motion at a single azimuthangle over a range of rotor speeds.

• To solve over a range of azimuth angles at a single rotor speed, use thePHIBGN, PHIDEL, and PHINUM parameters to specify the azimuth anglerange, and use the RSTART field to specify the rotor speed.

• To solve over a range of rotor speeds at a single azimuth angle, use thePHIBGN parameter to specify the azimuth angle, omit the PHIDEL andPHINUM parameters, and use the RSTART, RSTEP, and NUMSTEP fieldsto specify the rotor speed range. If you also omit the PHIBGN parameter,the solve is at an azimuth angle of zero because the default value for thePHIBGN parameter is zero.

5. The Steiner’s term option (ZSTEIN) should only be used when analyzing solidmodels in the fixed system.

6. The W3 parameter defines the reference frequency for structural damping definedby PARAM,G.

7. The W4 parameter defines the reference frequency for structural damping definedby GE.

8. Depending on element type, GE is specified on either material bulk entries,property bulk entries, or on the element bulk entries themselves.

9. The W3 and W4 parameters are required for all direct solutions. In the modalsolutions, the eigenvalues are used as default. If the W3 and W4 parametersare defined for modal analysis, they will be used, but these parameters are notrecommended for modal solutions.

10. The static centrifugal force is calculated for unit speed measured in rad/sec. Onthe RFORCE, RFORCE1, or RFORCE2 bulk entry, the unit of Hz is used, thus theconversion 1/(2π) = 0.159155 must be used by the user.

11. For calculating frequency response using synchronous analysis, the rotationspeeds are defined by the RSTART, RSTEP, and NUMSTEP fields on theROTORD bulk entry. The frequencies corresponding to these rotation speeds mustmatch the frequencies specified with the FREQUENCY case control command. Ifthe frequencies differ, a fatal error is issued.

12. For calculating the frequency or transient response using asynchronous analysis,the unique rotation speed is defined by the RSTART field on the ROTORDbulk entry. The RSTEP and NUMSTEP fields in this case will be ignored. Thefrequency and dynamic load definitions are defined with the standard FREQ,DLOAD, RLOAD, etc. bulk entries for frequency response, and with the TSTEP,DLOAD, TLOAD, etc. bulk entries for transient response.



Rotor dynamics

13. The rotor speed defined by RSTART, RSTEP, and NUMSTEP is called thereference rotor speed. Rotors with relative speed defined by RSPEED will spin atthe defined factor multiplied by the reference rotor speed.

14. The SYNC, ETYPE, and EORDER fields are ignored during a SOL 107 or SOL110 complex eigenvalue analysis. During a SOL 107 or SOL 110 complexeigenvalue analysis, if NUMSTEP = 0 and PARAM,ROTSYNC,YES (default)are specified, only synchronous analysis is performed. If NUMSTEP = 0 andPARAM,ROTSYNC,NO are specified, no analysis is performed.

15. For additional information on how the values in the THRSHOLD and MAXITERfields are used, see the PBEARbulk entry.

Expanded support for coupled solutionsIn rotor dynamic analyses, time-dependent coupling terms can arise in the equation of motionwhen rotors or the supporting structure are unsymmetrical. In versions prior to NX Nastran 10,these coupling terms were always excluded from the equation of motion. With NX Nastran 10, thesoftware allowed you to optionally include the coupling terms in the equation of motion for SOL 107,108, and 109 rotor dynamic analyses only. Beginning with NX Nastran 11, your ability to includetime-dependent coupling terms in the equation of motion is expanded to also include SOL 110,111, and 112 rotor dynamic analyses.

The procedure you use to include coupling terms in a SOL 110, 111, or 112 rotor dynamic analysisis identical to the procedure that you use to include the coupling terms in a SOL 107, 108, or 109rotor dynamic analysis. Specifically, you use the ROTCOUP parameter to trigger the inclusion ofthe coupling terms in the equation of motion, and you use the PHIBGN, PHIDEL, and PHINUMparameters to specify the azimuth angle range for the solve.

Expanded support for superelement style reduction of rotorsNX Nastran 10 provided you with the ability to apply superelement-style reduction to rotors. However,this capability was limited to SOL 107 direct complex eigenvalue analysis in rotor dynamics.Beginning with NX Nastran 11, this capability is expanded to SOL 108 direct frequency responseanalysis and SOL 109 direct transient analysis in rotor dynamics.

The procedure to use this new capability is identical to that for a SOL 107 direct complex eigenvalueanalysis in rotor dynamics.

• Include a ROTSE bulk entry for each rotor you want to reduce. The presence of the ROTSE bulkentry in the input file triggers the superelement-style reduction capability in rotor dynamics.Match the value in the RSETID field of each ROTSE bulk entry with the corresponding RSETifield for the rotor on the ROTORD bulk entry. For each rotor for which you define a ROTSE bulkentry, the software automatically assigns the grids on the corresponding ROTORG bulk entry toa unique o-set.

• On each ROTSE bulk entry, specify any grids that are listed on the corresponding ROTORG bulkentry that need to be removed from the o-set and placed in the a-set. Typically, these are thegrids that connect the rotor to the supporting structure, or are the grids where loads like massimbalance are applied.


Rotor dynamics


• On each ROTSE bulk entry, specify whether the software should use real or complex modalreduction. Generally, you will want to select complex modal reduction.

For more information, see the updated ROTSE bulk entry.



Rotor dynamics

ROTSE

Supplemental Rotor Superelement Definition

Defines the modal reduction type and additional a-set grids for a rotor superelement.Valid for SOLs 107, 108, and 109.

FORMAT 1:(FORMATS1 AND 2

CANNOT BECOMBINED

ON THE SAMELINE)

1 2 3 4 5 6 7 8 9 10

ROTSE RSETID TYPE EVID

G1 G2 G3 G4 G5 G6 G7 G8

FORMAT 2:

ROTSE RSETID TYPE EVID

G1 “THRU” G2 “BY” INC

CONTINUATIONFORMAT 1:

(CONTINUATIONFORMATS 1

AND 2CANNOT BECOMBINED

ON THE SAMELINE)

G9 G10 G11 G12 –etc.–

CONTINUATIONFORMAT 2:

G3 “THRU” G4 “BY” INC

EXAMPLE:

ROTSE 5 CX 1001

101 THRU 190 BY 5

46 23 57 82 9 16

201 THRU 255

93 94 95 97

FIELDS:

Field Contents

RSETID References an RSETi on the ROTORD bulk entry. See Remark1. (Integer>0)


Rotor dynamics


Field Contents

TYPE Modal reduction type. (Character: “RL”, “CX”)

= “RL”, use real modal reduction.

= “CX”, use complex modal reduction.

EVID Eigenvalue extraction data set identification number. (Integer>0)

For TYPE = “RL”, set identification number of an EIGRL bulk entry.

For TYPE = “CX”, set identification number of an EIGC bulk entry.

Gi Grids to remove from the o-set and place in the a-set. See Remark2. (Integer > 0)

THRU Specifies a range of grid ID's. (Optional)

BY Specifies an increment when using THRU option. (Optional)

INC Increment used with THRU option. (Integer > 0; Default=1)

REMARKS:1. The RSETID field is referred to by the RSETi field on the ROTORD bulk entry. If a

model contains multiple rotors, use separate ROTSE bulk entries for each rotor.

2. In a rotor dynamic analysis, the a-set consists of any grids that are not listed onany ROTORG bulk entry and any grids that are listed on any ROTSE bulk entry.

3. If the a-set does not contain at least one unconstrained DOF, the run terminates.

Superelement reduction of support structuresBeginning with NX Nastran 11, you can model the stationary portions of a rotor dynamics model asexternal, internal, or partitioned superelements. You use the same procedure and NX Nastran userinputs that you would if the model were not a rotor dynamics model.

For detailed information on how to create external, internal, and partitioned superelements, seethe NX Nastran Superelement User’s Guide.



Chapter 5: Multi-step nonlinear solution 401

Cyclic symmetricA new cyclic solution method is available in SOL 401. The new method takes advantage of cyclicsymmetry to reduce the time needed to create and solve a full 360 degree model. To use this method,you create a 3D-solid element model that represents a fundamental segment. The fundamentalsegment represents a structure that is made up of N repetitions, where each repetition can beobtained by rotating the fundamental segment an angle that is an integer multiple of 2π/N.

An important feature of this cyclic solution method is the automatic coupling of the translational DOFon the symmetry faces. The new CYCSET case control command, which selects the new CYCSETbulk entry, or multiple CYCSET entries with the new CYCADD bulk entry, defines the coupling. Thecoupling definition is required and must be defined globally. As a result, the MPC equations createdby the software are applied in every subcase.

To define the coupling, you select the cyclic source and target regions on the CYCSET bulk entry. Avery useful feature of the coupling definition is that the mesh on the source and target regions canbe dissimilar. In addition, features such as holes in one or both of the symmetry faces are alsopermitted. The software internally computes the correct coupling conditions between the grids onthe source and target faces.

The new CYCAXIS bulk entry is also required to define the default cylindrical coordinate system forthe coupling. The origin of this cylindrical system must be at the center of the revolution, and theZ-axis must be consistent with the axial direction.

CYCMODES subcase

A new cyclic modes subcase is available and designated with ANALYSIS=CYCMODES in thesubcase. The cyclic modes formulation includes the harmonic index, k, which represents an additionaldimension of the vector space that is not present in an "ordinary" modal analysis. For cyclic modelswith an even number of sectors (N is even), the allowable set of harmonics is 0,1, ...., N/2. For cyclicmodels with an odd number of sectors (N is odd), the allowable set of harmonics is 0,1,…, (N-1)/2.

You request the harmonic index values in which you want modes to be computed with theHARMONICS case control command, and a cyclic modal solution occurs for each harmonic indexindependently. For example, if you request 10 modes on the EIGRL bulk entry, and you request amodal solution for the 0th, the 1st, and the 2nd harmonic, a discrete cyclic modal solution occursfor each of these harmonics.

When computing the cyclic modes, the software uses a duplicate sector method. For harmonics k=0and k=N/2, there are distinct eigenvalues, and only one eigenvector component associated with eacheigenvalue. For all other harmonics (0 < k < N/2), each eigenvalue is repeated, and the displacement

vector for each corresponding eigenvalue has two components; the cosine component and the

sine component .

Static, bolt preload, and modal (non-cyclic modes) subcases



The static, bolt preload, and modal (non-cyclic modes) subcases can also be included in the input,and are designated with ANALYSIS=STATICS, ANALYSIS=PRELOAD, or ANALYSIS=MODALdefined in the subcase. These subcases use the MPC equations automatically created by thesoftware, but the displacements in the static and modal subcases are not cyclic. That is, thedisplacements only represent the 0th harmonic, n=1 fundamental sector.

Any of the subcase types (statics, preload, modal and cyclic modes) can be defined as sequentiallydependent. The parameters STRESSK, SPINK and FOLLOWK on the NLCNTL bulk entry can bedefined to request stress stiffening, spin softening, and follower stiffness, respectively.

Cyclic clocking and normalization for the CYCMODES subcase

As a result of the inherent symmetry with the cyclic modal solution, modes occur in pairs forharmonics 1 through N/2-1, where N is the total number of sectors.

Once NX Nastran computes the normal modes, it uses the initially computed global displacementvectors to do the following:

• The software clocks the eigenvector solution to the fundamental sector. This clocking ensuresthat, for the first mode in a mode pair, the maximum nodal displacement occurs on thefundamental sector.

• If you have selected either the AFNORM or DISP normalization options, the softwarerenormalizes using the maximum displacement relative to all sectors.

The clocking and normalization procedure is as follows.

The displacement result for a single mode and harmonic is represented by the equation:

The global displacement vectors and in a single mode are orthogonal to each other. In

addition, from one mode in a pair is related to from the same pair.

For a travelling wave with equal amplitude in any mode pair, every grid point traverses an ellipse inthree dimensional space. The maximum resultant displacement is the major axis of the ellipse. For agrid point i, the maximum resultant displacement is computed as follows.

is the cyclic cosine displacement vector (three components) at a specific grid point.

is the cyclic sine displacement vector (three components) at a specific grid point.

The software computes the following using the cyclic cosine and sine vectors:

The resultant displacement at each grid point i is computed as:



Multi-step nonlinear solution 401

The software determines the grid point with the maximum resultant displacement. For this grid pointii, the phase angle is computed as:

This phase angle will be used to clock the displacements to the fundamental sector.

The maximum displacement found at grid point ii is used to compute the normalization factor:

• For AF normalization, the factor is computed as:

where,

ω is the frequency for the mode, and

AFNORM is the parameter setting PARAM, AFNORM which defaults to 1.0.

For the modes considered as rigid body modes, the software sets ω = 1 when computing the AFnormalization factor. The software considers a mode to be a rigid body mode if its frequency isbelow the value of the new parameter AFZERO (default=1.0 hz).

• For unit (MAX) normalization, the factor is computed as:

• For mass (MASS) normalization, the factor f=1.0 is used since the eigenvector was already massnormalized when the modes were computed initially.

The cyclic cosine and sine components are then clocked based on the computed values of .

The cyclic components for each mode are then reset to these new values:

Cyclic modes subcase input summary

• The automatic coupling definition is required. The inputs for the coupling are described under the‘Automatic Coupling Details’ heading below.




• The ANALYSIS=CYCMODES case control command is defined in the specific subcases in whichyou are requesting the new cyclic modes solution method.

• The HARMONICS case control command requests the specific harmonics in which modes arecomputed. "ALL" requests all possible harmonics. If you define the SID of a SET bulk entry,the SET entry lists the harmonic numbers to be computed, including "0" to request the zerothharmonic.

The maximum harmonic for a model is related to the total number of segments which wouldtheoretically exist to represent the full model.

o For an even total number of segments:

Maximum harmonic = Total number of segments/2.

For example, if a 30 degree segment is modeled, the total number of segments to create afull model is 360/30 = 12. Since 12 is even, the maximum harmonic = 12/2=6.

o For an odd total number of segments:

Maximum harmonic = (Total number of segments-1)/2.

For example, if a 40 degree segment is modeled, the total number of segments is 360/40= 9. Since 9 is odd, the maximum harmonic = (9-1)/2 = 4.

o As a result of the inherent symmetry in the cyclic modal solution, mode pairs exist forharmonic numbers 1 through N/2 -1. The software automatically outputs the mode pairsfor these subcase types for the modes requested with the EIGRL entry. For example, ifyou request 10 modes on the EIGRL entry:

For harmonic index 0 and N/2, 10 modes are computed.

For harmonic numbers 1 through N/2 -1, 20 modes are computed (10 distinct modes).

This behaviour is consistent for modes requested with the OMODES case control command.See the remarks on the OMODES command for details.

• The HOUTPUT case control command optionally requests the harmonics to output modes. "ALL"requests output for every harmonic requested on the HARMONICS command. You can definean integer to select the SID of a SET bulk entry, which lists the harmonic numbers to be output.These IDs are a subset of the IDs requested on the HARMONICS command. The C, S, C*, andS* describers on the HOUTPUT command are not supported by SOL 401.

• The METHOD case control command selects the EIGRL bulk entry which then defines theeigenvalue solution options. For example, the lower and upper frequency ranges and the numberof modes. Since a single EIGRL entry is selected in a subcase, the same EIGRL options areused when the software computes the modes for each harmonic.

Automatic Coupling Details

• The symmetry faces are grouped into source and target regions. To do the automatic coupling,NX Nastran internally rotates the target region grids into the source region grids, it does a meshrefinement on both the source and target, and then creates MPC equations using the target asthe dependent DOF and the source as the independent DOF. The MPC equations are created




between any source and target region grids within the user defined search distance (SDISTi)using a weighted area method.

• The mesh on the source and target regions can be dissimilar. Features such as holes in one orboth of the symmetry faces are also permitted.

• It is recommended that the source and target faces have similar geometry. If the source andtarget geometry is different, the software will still couple the appropriate source and target grids,although, the solution accuracy will be comprimised.

• You must define the automatic coupling globally. The resulting MPC equations are included inall subcases, including any static, preload, and modal (that is, a non-cyclic modes subcasewith ANALYSIS=MODAL).

Automatic coupling input summary

• The new CYCAXIS bulk entry is required to define the default cylindrical coordinate system forthe coupling. The origin of this cylindrical system must be at the center of the revolution, and theZ-axis must be consistent with the axial direction.

• The Z-axis of every cylindrical coordinate system referenced by the CYCSET entry must havethe same origin and direction as the z-axis of the default coordinate system selected with theCYCAXIS bulk entry.

• The displacement coordinate system of grid points which are defined on the rotation axis musthave a Cartesian displacement coordinate system. For all other grid points, a cylindricaldisplcement coordinate system is recommended. See Rules for source and target DOF.

• The CYCSET case control selects the CYCSET or CYCSADD bulk entries. The CYCSETcase control must be defined above the subcase level. As a result, the MPCs generated bythe automatic coupling are used in every subcase (cyclic modes, static, and "normal" normalmodes subcases).

• The BSURFS and BCPROPS bulk entries define the regions. These are existing inputs usedto define glue and contact regions.

• The CYCSET bulk entry pairs the source and target face regions.

o The source region selected in a pair must have a smaller positive theta location than thetarget region.

o The software will use the number of segments (NSEG) field to compute the angle betweenthe source and target faces. For example, if a 30 degree segment is modeled, NSEGwould be 12 = (360/30).

o The SDIST field is used to pair source and target grids when creating the MPC equations.From each source grid, the search occurs in both the positive and negative theta DOFdirections. If the SDIST field is undefined, the software will automatically compute the searchdistance. The software computed value is reported in the f06 file.




• The CYCADD bulk entry can optionally be used to combine multiple CYCSET bulk entries. Thevalue defined in the NSEG field on all CYCSET entries referenced by a CYCADD entry must bethe same. A fatal error will occur if any are inconsistent.

• The CYCFORCES case control command optionally requests the MPC force output for the gridswhich are included in the automatic coupling. It can be defined above the subcases (globally)or in a subcase.

Rules for source and target DOF

• If you define SPC conditions on target region DOF with the SPC, SPC1, or SPCD entries, thesoftware reports a warning message that it is ignoring the SPC conditions on the target regionDOF, and the solution continues.

• If you include a target region DOF on an RBE2, RBAR, or RBE3 element as a dependent DOF,the software reports a warning message that it is ignoring the rigid connections on the targetregion DOF, and the solution continues.

• If you include a source or target region DOF on an MPC bulk entry as a dependent DOF, thesolution ends with a fatal error.

• Grid points which are defined on the Z-axis of the default cylindrical coordinate system must havea Cartesian displacement coordinate system. For the grid points which are defined on the Z-axisand are included in a source or target region, in addition to any conditions that you defined, NXNastran automatically applies the following SPC conditions during the solution.

o For the harmonic index k=0, NX Nastran fixes DOF 1, 2.

o For the harmonic index k=1, NX Nastran fixes DOF 3.

o For all other harmonic index values, NX Nastran fixes all six DOF.

Post-processing the results

NX Nastran outputs results for the fundamental sector. Due to the symmetric nature of the problemand the orthogonal nature of the modes, the results for the entire structure (360 degree model) canbe inferred from the results of the fundamental sector.

• For the 0th harmonic:

=

Where,

n = sector for which results are to be inferred.

= Results corresponding to the fundamental sector at harmonic 0.

results for sector n at harmonic 0.

• For harmonic k (0 < k < N/2),




Where,

N = Total number of sectors.

n = Sector for which results are to be inferred.

k = Harmonic index

= Cosine cyclic component for the k harmonic of the mode being computed for thefundamental sector.

= Sine cyclic component for the k harmonic of the mode being computed for the fundamentalsector.

R = any output quantity of interest. For example, displacement or stress.

• For harmonic N/2:

Where,

n = Sector for which results are to be inferred.

= results corresponding to the fundamental sector at harmonic N/2.

= results for sector n at harmonic N/2.




ANALYSIS

Analysis Discipline Subcase Assignment

Specifies the type of analysis being performed for the current subcase.FORMAT:

ANALYSIS=typeEXAMPLES:

ANALYSIS=STATICSANALYSIS=MODES

DESCRIBERS:

Table 5-1. SOL 200 Analysis Types

Describer Meaning

type Analysis type. Allowable values and applicable solution sequences(Character):

STATICS Statics

MODES Normal Modes

BUCK Buckling

DFREQ Direct Frequency

MFREQ Modal Frequency

MTRAN Modal Transient

DCEIG Direct ComplexEigenvalue Analysis

MCEIG Modal ComplexEigenvalue Analysis

SAERO Static Aeroelasticity

DIVERGE Static AeroelasticDivergence

FLUTTER Flutter

SOL 200


Describer Meaning






Describer Meaning

STATICS Statics

MODES Normal Modes

PRELOAD Bolt Preload

CYCMODES Cyclic Modes

FOURIER Fourier Modes

SOL 401

Table 5-3. SOLs 108, 110, 111, and 112 Analysis Types

Describer Meaning


MODES Normal Modes SOLs 110, 111, and112 only.

RANDOM Random Analysis SOLs 108 and 111only.

Table 5-4. SOLs 153, 159, 601,153 and 601,159 Analysis Types

Describer Meaning


HEAT Heat TransferAnalysis

STRUCTURE Structural Analysis

SOLs 153, 159,601,153 and 601,159

only.

REMARKS:1. ANALYSIS = STRUC is the default in SOLs 153 and 159.

2. In SOL 200, all subcases, including superelement subcases, must be assignedby an ANALYSIS command either in the subcase or above all subcases. Also,all subcases assigned by ANALYSIS=MODES must contain a DESSUB request.If a SOL 200 job contains both ANALYSIS=STATICS and ANALYSIS=BUCKsubcases, the STATICS subcases should come before ANALYSIS=BUCK. A SOL200 job may not contain both DFREQ and MFREQ subcases at the same time.




3. ANALYSIS=DIVERG is only available for analysis in SOL 200. Sensitivity andoptimization are not supported for this analysis type.

4. In order to obtain normal modes data recovery in SOLs 110, 111, and 112,ANALYSIS = MODES must be specified under one or more separate subcase(s)which contains requests for data recovery intended for normal modes only. Forexample, in SOL 111:

METH=40SPC=1SUBCASE 1 $ Normal ModesANALYSIS=MODESDISP=ALL

SUBCASE 2 $ Frequency responseSTRESS=ALLDLOAD=12FREQ=4

All commands which control the boundary conditions (SPC, MPC, and SUPORT)and METHOD selection should be copied inside the ANALYSIS=MODES subcaseor specified above the subcase level.

5. ANALYSIS = RANDOM is only available for analysis in SOLs 108 and 111. Itis used to simplify the process of performing multiple random analyses via theRANDOM and optionally RCROSS case control commands over frequencyresponse subcases of the same frequencies. For example, in SOL 111:

SDAMPING=101SPC=2ACCELERATION(RPRINT)=ALLSTRESS(SORT2,PSDF)=ALLRCROSS(PRINT)=1METHOD=1$SUBCASE 1 $ Normal ModesANALYSIS=MODESDISP=ALL





$ Change frequenciesSUBCASE 11 $ Frequency Response using FREQ set 23FREQUENCY=23DLOAD=111

SUBCASE 12 $ Frequency Response using FREQ set 23




FREQUENCY=23DLOAD=211



REMARKSRELATED TO

SOL 601:1. ANALYSIS=STRUC and ANALYSIS=HEAT are supported for SOL 601,153 and

SOL 601,159.

2. For SOL 601,153 and SOL 601,159, two subcases are required. The firsttwo subcases must be one with ANALYSIS=STRUC (default) and one withANALYSIS=HEAT. The parameter COUP in TMCPARA bulk entry is used tospecify the type of coupling between the structural and heat transfer analysis.




CYCSET

Selects a cyclic symmetric boundary coupling in SOL 401.

Selects a cyclic symmetric boundary coupling in SOL 401.FORMAT:

CYCSET=nEXAMPLES:

CYCSET=5

DESCRIBERS:

Describer Meaning

n Set identification of a CYCSET or CYCADD bulk entry. (Integer>0)

REMARKS:1. n can reference a single CYCSET bulk entry, or it can reference the CYCADD bulk

entry which combines multiple CYCSET entries.

2. The CYCSET case control selects the CYCSET or CYCADD bulk entries. TheCYCSET case control must be defined above the subcase level. As a result, theMPC's generated by the automatic coupling are used in every subcase (cyclicmodes, static, and normal modes subcases).




CYCSET

Defines pairs for cyclic symmetry in SOL 401

Defines pairs for cyclic symmetry in SOL 401.FORMAT:

1 2 3 4 5 6 7 8 9 10CYCSET CYSID NSEG CSID

SID1 TID1 SDIST1

SID2 TID2 SDIST2

-etc-

EXAMPLE:

CYCSET 4 11 6

1 2

4 3

FIELDS:

Field Contents

CYSID CYCSET set identification number. (Integer>0)

NSEG Number of segments (Integer>1)

CSID Identification number of a cylindrical coordinate system. (Integer>0 orblank; Default = CSYS selected with the CYCAXIS entry)

NSEG Number of segments. (Integer>1)

SIDi Source region identification number for CYCSET pair i. (Integer>0)

TIDi Target region identification number for CYCSET pair i. (Integer>0)

SDISTi Search distance for CYCSET pairs (Real); (Default=1.0e-3)

REMARKS:1. The SIDi and TIDi fields select the BSURFS and BCPROPS bulk entries. These

entries define regions on the faces of the CHEXA, CPENTA, CPYRAM, andCTETRA elements.

2. The source region selected in a pair must have a smaller positive theta locationthan the target region.

3. To do the automatic coupling, NX Nastran internally rotates the target regiongrids into the source region grids, it does a mesh refinement on both the sourceand target, and then creates MPC equations using the target as the dependentDOF and the source as the independent DOF. The MPC equations are createdbetween any source and target region grids within the user defined searchdistance (SDISTi) using a weighted area method. From each source grid, the




search occurs in both the positive and negative theta DOF direction. The SDISTfield is required for each pair of regions.

4. The software will use the number of segments (NSEG) field to compute the anglebetween the source and target faces. For example, if a 30 degree segment ismodeled, NSEG would be 12 (=360/30).

5. The z-axis of the cylindrical coordinate system selected in the CSYS field musthave the same origin and direction as the z-axis of the default coordinate systemselected with the CYCAXIS bulk entry.




CYCADD

Combines cyclic symmetry sets in SOL 401

Combines cyclic symmetry sets in SOL 401.FORMAT:

1 2 3 4 5 6 7 8 9 10CYCADD SID S1 S2 S3 S4 S5 S6 S7

S8 S9 S7 -etc-

EXAMPLE:

CYCADD 12 1 3 6 5 9

FIELDS:

Field Contents

SID Cyclic set identification number. (Integer>0)

Si Identification numbers of cyclic sets defined with CYCSET entries.(Integer>0)

REMARKS:1. Multiple cyclic sets (CYCSETs) with unique SIDs can be combined by including

their SIDs on a CYCADD entry. The CYCADD entry has its own unique CYCSIDwhich is used on the CYCSET case control command. Multiple cyclic sets withtheir own CYCSID are a modeling conveience. A single CYCSET Bulk data canbe defined with multiple pairs or pairs can be defined in their own CYCSET andcombined with the CYCADD.

2. CYCSID’s must be unique and may not be the identification of the CYCADD entry.

3. The value defined in the NSEG field on all CYCSET entries referenced by aCYCADD entry must be the same. A fatal error will occur if any are inconsistent.




CYCAXIS

Default cylindrical coordinate system for a SOL 401 cyclic model

Default cylindrical coordinate system for a SOL 401 cyclic modelFORMAT:

1 2 3 4 5 6 7 8 9 10CYCAXIS CSID

EXAMPLE:

CYCAXIS 101

FIELDS:

Field Contents

CSID Identification number of the default cylindrical coordinate system for aSOL 401 cyclic model (Integer≥0).

REMARKS:1. The CYCAXIS bulk entry is required to define the default cylindrical coordinate

system for the automatic coupling selected with the CYCSET case control. Theorigin of this cylindrical system must be at the center of the revolution, and thez-axis must be consistent with the axial direction.

2. The z-axis of every cylindrical coordinate system referenced by the CYCSET entrymust have the same origin and direction as the z-axis of the default coordinatesystem selected on the CYCAXIS bulk entry.




CYCFORCES

Requests MPC force output at the grid points selected for the automatic couplingin a SOL 401 cyclic symmetry analysis.

Requests MPC force output at the grid points selected for the automatic couplingin a SOL 401 cyclic symmetry analysis.

FORMAT:

EXAMPLES:CYCFORCES=ALLCYCFORCES(PRINT,PUNCH)=17

DESCRIBERS:

Describer Meaning

PRINT Compute and write output to the print file (f06). (Default)

PUNCH Compute and write output to the punch file (pch).

PLOT Compute output.

ALL Requests output for all grid points.

n Set identification number of a previously appearing SET command.The SET command is a list of grid point IDs. (Integer>0)

NONE Output is not computed.

REMARKS:1. Only supported in a static subcase for SOL 401.

2. The CYCFORCES output only occurs on the grid points included in a couplingsource and target region. The grid points listed on the referenced SET commandshould be included in a coupling region. Grid points listed in a referenced SETwhich are not in a source or target region will be ignored.




NLCNTL

Strategy Parameters for SOL 401

Defines solution control parameters for SOL 401.

FORMAT:

1 2 3 4 5 6 7 8 9 10NLCNTL ID PARAM1 VALUE1 PARAM2 VALUE2 PARAM3 VALUE3

PARAM4 VALUE4 PARAM5 VALUE5 -etc-

EXAMPLE:

NLCNTL 1 MAXITER 30 CONV UPW MAXDIV 2

SOLVER ELEMITER

FIELDS:

Field Contents

SID Identification number. (Integer > 0)

PARAMi Name of the NLCNTL parameter. Allowable names are given in theparameter listing below. (Character)

VALUEi Value of the parameter. (Real, Integer, or Character)

NLCNTLPARAMETERS:

Table 5-5. General Convergence and Iteration Control Parameters

Name Description

CONV Specifies the convergence criteria. See Remark 8. (Character = “U”,“P”, “W”, or any combination; Default = “W”)

EPSP Error tolerance on force. (Real > 0.0; Default = 1.0E-2)

EPSU Error tolerance on displacement. (Real > 0.0; Default = 1.0E-2)

EPSW Error tolerance on work. (Real > 0.0; Default = 1.0E-6)

MAXBIS Maximum number of bisections allowed. (0 < Integer < 10; Default = 5)

MAXDIV Number of divergences before solution is assumed to diverge. (Integer> 0; Default = 3)

MAXITER Maximum number of iterations per time step. (Integer > 0; Default = 25)




Table 5-5. General Convergence and Iteration Control Parameters

Name Description

MAXQN Maximum number of quasi-Newton correction vectors to be saved.(Integer ≥ 0; Default = 10)

Table 5-6. Bolt Preload Parameters

Name Description

EPSBOLT Convergence tolerance for a nonzero bolt preload. See Remark 9.(Real > 0.0; Default = 1.0E-3)

ZERBOLT Convergence tolerance for a zero bolt preload. See Remark 9.(Real>0.0; Default=1.0E-7)

ITRBOLT Maximum number of bolt iterations before the bolt preload calculation isconsidered non-converged. See Remark 9. (Integer > 0; Default = 20)

MISFBLT Limits the bolt strain from one preload increment to the next. (Real >1.0E-6; No default. The software does not apply MISFBLT when it isundefined.)

MISFBLT is useful, for example, if you model a bolted joint with agap condition. The bolt preload algorithm increments the bolt strainas the joint compresses. When a gap is present, before the joint iscompressed, the axial bolt force will be relatively low. As a result, thepreload algorithm will increase the strain increments. Once the gap isclosed and the joint begins to compress, the bolt and contact forces willchange quickly, possibly causing the contact conditions to destabilized.By limiting the bolt preload strain increments, you can reduce thechance of destablization, and utlimately help achieve convergence.

At the start of a bolt preload solution, the software uses your requestedpreload force and the bolt geometry to estimate a bolt strain. Theestimated strain (εes) is computed with the assumption that everythingis rigid except for the bolt. The software then computes the maximumallowable strain increment using the new MISFBLT parameter.

Δεmax = εes * MISFBLT

At each preload increment, the software compares Δεmax with the nextcomputed preload increment Δεi+1. The software uses the smaller ofthe two at each preload increment.




Table 5-6. Bolt Preload Parameters

Name Description

MSGLVLB Diagnostic output for bolt preload. (Integer = 0, 1, or 2; Default = 1)

0: Bolt summary messages upon convergence.

1 -Bolt summary messages at every bolt preload iteration.

2 - Bolt summary messages and load/tolerance messages per bolt atevery bolt preload iteration.

MSGLVLB=1 and 2 requires MSGLVL=1. If MSGLVL= 0, MSGLVLB isalso forced to 0, even if MSGLVLB=1 or 2 are defined. MSGLVLB 1and 2 also output a table of bolt data showing the forces, moments andstrains per bolt. This is only after the bolts converge.

Table 5-7. General Solution Parameters

Name Description

LVAR Specifies whether time unassigned loads are ramped or stepped.(Character = ”RAMP” or ”STEP”; Default = “RAMP”)

MSGLVL Diagnostic level. (Integer = 0 or 1; Default = 1)

0: No additional diagnostic output

1: Convergence information is output for each iteration

SOLVER Specifies the solver. See Remark 10. (Character = “SPARSE”,“PARDISO”, “MUMPS”, or “ELEMITER”; Default = “SPARSE”)

THRMST Include thermal strain in a static analysis (Character = “YES” or “NO”;Default = “YES”)

TVAR Specifies whether time unassigned temperature loads are ramped orstepped. (Character = ”RAMP” or ”STEP”; Default = “RAMP”)

Table 5-8. Stiffness Control Parameters

Name Description

FOLLOWK Include follower stiffness. Follower stiffness is computed from thefollower loads defined with the FORCE1, FORCE2, PLOAD, orPLOAD4 entries. (Character = “YES” or “NO”; Statics default = “NO”;Modal default = “YES”)




Table 5-8. Stiffness Control Parameters

Name Description

KUPDATE Stiffness update strategy. (Integer; Default = 0)

-1: Initial stiffness approach

0: Auto stiffness update

1: Full Newton-Raphson

>1: Quasi Newton-Raphson, and KUPDATE is the number of iterationsbefore a stiffness update

SPINK Include spin softening. See Remark 11. (Character = “YES” or “NO”;Statics default = “NO”; Modal default = “YES”)

STFOPTN Material stiffness matrix option. (Integer ≥ 0; Default = 3)

1: The elastic stiffness matrix is used.

2: The tangent stiffness matrix is used.

3: The elastic stiffness matrix is used to start each subcase, the elasticstiffness matrix is used if a stiffness update is requested prior to thebeginning of a new time step, and the tangent stiffness matrix is usedat any intermediate stiffness update.

STRESSK Include stress stiffening. (Character = “YES” or “NO”; Statics default= “YES”; Modal default = “YES”)

TSTEPK Stiffness is updated at the beginning of the time step. Applicable only ifKUPDATE>1. (Character = “YES” or “NO”; Default = “NO”)

Table 5-9. Contact Parameters

Name Description

CNTMDIV Number of permissible contact divergences before besection isinitiated. (Integer > 0; Default = 9)

Friction defined with the FRICi field on the BCTSET bulk entry along with slidingcontact conditions can result in unsymmetric stiffness terms in the global stiffnessmatrix. Including the unsymmetric stiffness terms will slow the solution performance,although the unsymmetric terms are sometimes necessary to achieve solutionconvergence. You can use the FSYMTOL, KSYM and KSYMTOL parameters tocontrol if the unsymmetric terms are included.





Name Description

FSYMTOL Contact friction coefficient threshold to control if the sliding contactstiffness includes the unsymmetric stiffness term. (Real ≥ 0.0; Default =0.2)

When the maximum FRICi for all contact pairs is less than FSYMTOL,the unsymmetric stiffness term is not included, and a symmetricstiffness is generated.

When the maximum FRICi for all contact pairs is greater thanFSYMTOL, the unsymmetric stiffness term is included, and anunsymmetric stiffness is generated.

KSYM When an unsymmetric material stiffness is generated as described inthe FSYMTOL description, KSYM controls if the unsymmetric matrixis symmetrized. (Character = “AUTO”, “SYM”; or “UNSYM”; Default= “AUTO”)

SYM: The unsymmetric matrix is always symmetrized.

UNSYM: The unsymmetric matrix is never symmetrized.

AUTO: The unsymmetric matrix is symmetrized if the KSYMTOLtolerance is satisfied as described below.

KSYMTOL Tolerance for symmetrizing the unsymmetric global stiffness whenKSYM=AUTO. (Real ≥ 0.0; Default = 0.001)

If Kfull is the unsymmetric global stiffness, the symmetric part Ksp is:

The unsymmetric part Kup is:

The ratio of the unsymmetric part to the full matrix is:

The ratio r is a measure of the matrix asymmetry. It is compared withthe KSYMTOL.

If r < KSYMTOL, the unsymmetric matrix is symmetrized.

If r > KSYMTOL, the unsymmetric matrix is used.





Name Description

MSGLVLC Diagnostic output for contact. (Integer = 0, 1 or 2; Default = 1)

0: No additional diagnostic output.

1: Convergence information is printed for each iteration. Changes incontact status are also printed. Before the first iteration, a summary ofthe number of sliding/sticking/active/inactive elements is printed. Thenumber of augmentations and number of pair updates is also printed.

2: Everything described in option 1 and after each iteration, detailedinformation for every contact pair is printed.

USOLVER Selects the unsymmetric solver. (Character = “HYBRID”, “SPARSE”,“PARDISO”, or “MUMPS”; Default = “HYBRID”)

Table 5-10. Plasticity and Creep Control Parameters

Name Description

CRCERAT For the ratio of maximum creep increment to elastic strain method,the ratio of maximum creep increment to elastic strain that is used tocalculate the next time step. Valid for creep analysis only. (Real ≥0.0; Default = 0.4)

CRCINC For the maximum creep increment method, the maximum creepincrement that is used to calculate the next time step. Valid for creepanalysis only. (Real ≥ 0.0; Default = 1.0E-4)

CREEP Include creep effects. (Character = “YES” or “NO”; Default = “YES”)

CRICOFF Creep strain increment below which the next time step is the product ofthe current time step and CRMFMX. Valid for creep analysis only. (0.0< Real < 1.0; Default = 1.0E-6)

CRINFAC Integration factor used to calculate incremental creep strain. Valid forcreep analysis only. See Remark 5. (0.0 ≤ Real ≤ 1.0; Default = 0.5)

CRMFMN Minimum time step multiplying factor. If the next time step calculated bythe adaptive time stepping algorithm is smaller than the product of thecurrent time step and CRMFMN, the software halves the current timestep, recalculates the current creep strain increment, and reenters theadaptive time stepping algorithm at the point the creep strain incrementis compared to CRICOFF. Valid for creep analysis only. (0 ≤ Real ≤1.0; Default = 0.1)




Table 5-10. Plasticity and Creep Control Parameters

Name Description

CRMFMX Maximum time step multiplying factor. See the CRICOFF parameterfor additional information. Valid for creep analysis only. (Real ≥ 1.0;Default = 5.0)

CRTEABS Maximum absolute truncation error. Valid for creep analysis only. (0.0≤ Real < 1.0; Default = 1.0E-4)

CRTECO For the error truncation method, use CRTEABS to calculate the nexttime step if the creep strain is less than CRTECO, and use CRTEREL tocalculate the next time step if the creep strain is greater than CRTECO.Valid for creep analysis only. (0.0 ≤ Real < 1.0; Default = 1.0E-4)

CRTEREL Maximum relative truncation error. Valid for creep analysis only. (0.0 ≤Real < 1.0; Default = 0.01)

PLASTIC Include plasticity effects. (Character = “YES” or “NO”; Default = “YES”)

Table 5-11. Time Step Control Parameters

Name Description

AUTOTIM Automatic timing scheme ON/OFF parameter. When AUTOTIM=ON(default), automatic time step strategy will be used. SettingAUTOTIM=OFF turns off the automatic time stepping scheme.(Character = "ON" or "OFF"; Default="ON")

DTINIT Initial time step or constant time step. (Real > 0.0; Default = 0.01)

DTMAX Maximum time step. If DTMAX is set to 0.0 (default), the softwareaccepts the next time step. If DTMAX is nonzero and the next timestep is larger than DTMAX, the software uses DTMAX as the next timestep. Otherwise, the next time step is compared to DTMIN. (Real ≥0.0; Default = 0.0)

DTMIN Minimum time step. If the next time step is larger than DTMIN, thesoftware accepts the next time step. For creep analysis, if the nexttime step is smaller than DTMIN, the software halves the current timestep, recalculates the current creep strain increment, and reentersthe adaptive time stepping algorithm at the point the creep strainincrement is compared to CRICOFF. (0.0 ≤ Real ≤ DTMAX; Default =0.001*DTINIT)





Name Description

DTSBCDT Option to use DTINIT or not in a new subcase. A subcase with a zerostart time always uses DTINIT. (Integer; Default = 1)

0: Use the time step calculated at the end of the previous subcase.

1: Use DTINIT

EQMFMIN Minimum time step factor for equilibrium iteration criterion. (Real >0.0; Default=0.2)

EQMFMX Maximum time step factor for equilibrium iteration criterion. (Real> 0.0; Default=5.0)

TSCCR Specifies the time stepping method. Valid for creep analysis only. SeeRemarks 6 and 7. (Integer or blank; Default = 12)

0: Use constant time stepping

1: Use adaptive time stepping based on the error truncation methodonly

2: Use adaptive time stepping based on the ratio of maximum creepincrement to elastic strain method only

3: Use adaptive time stepping based on the maximum creep incrementmethod only

12: Use adaptive time stepping based on both the error truncationmethod and the ratio of maximum creep increment to elastic strainmethod

13: Use adaptive time stepping based on both the error truncationmethod and the ratio of maximum creep increment method

23: Use adaptive time stepping based on both the ratio of maximumcreep increment to elastic strain method and the maximum creepincrement method

123: Use adaptive time stepping based on the error truncation method,the ratio of maximum creep increment to elastic strain method, and themaximum creep increment method

TSCEQ Flag to turn ON/OFF stepping based on equilibrium iterations.(Character = "ON" or "OFF"; Default="ON")

TSCUMAT Flag to activate stepping based on UMAT supplied time increments.(Character = "ON" or "OFF"; Default="ON")

UMFMIN Minimum time step factor for UMAT stepping. (Real > 0.0; Default=0.2)





Name Description

UMFMX Maximum time step factor for UMAT stepping. (Real > 0.0; Default=5.0)

REMARKS:1. The NLCNTL bulk entry must be selected with the NLCNTL = SID case control

command.

2. NLCNTL case control commands can be placed inside subcases. Because eachNLCNTL case control command can point to a different NLCNTL bulk entry, theNLCNTL parameter settings can vary from subcase to subcase.

3. A fatal error occurs when a PARAMi field is defined and the corresponding VALUEifield is left blank.

4. If an NLCNTL parameter is applicable to a certain type of analysis, but it is notdefined on an NLCNTL bulk entry, the default value for the parameter is used.

5. Incremental creep strain, Δεc, is calculated from the generalized trapezoidal ruleas follows:

where Δt is the current time step, έ ct is the creep strain rate at t, έ ct+Δt is the creepstrain rate at t+Δt, and β is the integration factor specified with the CRINFACparameter.

6. Solution times are the times specified by the TENDi and NINCi fields on TSTEP1bulk entries. At all times during the creep analysis, if the next time step wouldresult in skipping over a solution time, the software truncates the next time step sothat a solve occurs at the solution time. If a time step is truncated to avoid skippingover a solution time, the truncated time step is not subject to the any minimumtime step requirement.

7. When you select an adaptive time stepping algorithm that is based on multiplemethods, the software calculates a value for the next time step from each selectedmethod. The software compares the values and uses the smallest as the nexttime step.

8. The convergence test flags (U = displacement error, P = load equilibrium error,and W = work error) and the tolerances (EPSU, EPSP, and EPSW) define theconvergence criteria. All the requested criteria (combination of U, P, and/or W) aresatisfied upon convergence.

9.

• When the software determines that your requested preload is nonzero, if thedifference between the software computed preload and the user-defined




preload is less than EPSBOLT, the bolt preload calculation is consideredconverged. If the difference is greater than EPSBOLT, the preload strain ismodified accordingly for the next bolt preload iteration. The iterations continueuntil either convergence is satisfied, or the number of iterations reachesITRBOLT.

• When the software determines that your requested preload is zero, it usesZERBOLT to check for convergence by checking if P/AE < ZERBOLT, where Pis the axial bolt force from an applied axial strain value, A is the area of the boltcross section, and E is the modulus of the material selected for the elementson the bolt. EPSBOLT is ignored for a zero bolt preload.

Note that the software considers a bolt preload force to be zero when F/AE <ZERBOLT, where F is the preload force you requested on the BOLTFOR entry.A preload of 0.0 always satisfies this, but it is also possible for the preload tobe nonzero, yet A and E are large enough for the software to determine thatthe zero preload convergence checking should be used.

10. SOL 401 supports the sparse direct solver (default), the element iterative solver,and the PARDISO solver (NLTRD3 nonlinear solution module). To select the SOL401 solver type, define the SOLVER parameter as SPARSE (default), ELEMITER,or PARDISO. When the element iterative solver is selected, you can optionallydefine the SMETHOD case control command and the ITER bulk entry to alter thedefault options available on the ITER entry.

11. If spin softening is requested with the SPINK parameter, and a rotational force isdefined with the RFORCE or RFORCE1 entry, if a grid point is selected in the Gfield on the RFORCE or RFORCE1 entry to define the rotation center, and thisgrid point is not used in the connectivity of any element, all translational DOFfor this grid point must be constrained.

Fourier harmonic solutionA new Fourier normal modes subcase is available in SOL 401 for models which include axisymmetricelements. The subcase is designated with the ANALYSIS=FOURIER and HARMONICS=N casecontrol commands in the subcase.

The conventional axisymmetric element includes radial and axial degrees-of-freedom with novariation in theta.

In the Fourier normal modes subcase, the axisymmetric element has radial, axial and thetadegrees-of-freedom. In addition, the degrees-of-freedom are represented with harmonic terms of aFourier series of the form:

where:

c=cos(kθ),




s=sin(kθ),

k is the harmonic number,

are symmetric displacements,

are antisymmetric displacements

Both symmetric and antisymmetric displacements are computed by NX Nastran for a particularharmonic k.

With the new Fourier normal modes subcase, you request the harmonic numbers for which a modalsolution should occur, and the harmonic terms for modal output. For each harmonic number inwhich you request modes and output, the software can compute the symmetric and antisymmetricdisplacements, stress, strain, SPC force and grid point forces. You can use the typical case controlcommands to request the output. You can then optionally use the NX post processor to display thephysical results on either a 3D segment, or on a full 360 degree model display.

The modal solution for each harmonic term is discrete, and independent of other harmonic terms. Forexample, if you request 10 modes on the EIGRL bulk entry, and you request a modal solution forthe 0th, the 1st, and the 2nd harmonic term, a discrete modal solution will occur for each of theseharmonics. You will have 10 modes for the 0th, 10 modes for the 1st, and 10 modes for the 2nd term,and there is no coupling of the mode results between the different harmonics.

Static and modal (non-Fourier normal modes) subcases can also be included in the input, and aredesignated with the case control commands ANALYSIS=STATICS or ANALYSIS=MODAL. Theconventional axisymmetric element formulation is used in the static and modal subcases.

The Fourier normal modes subcase can optionally be sequentially dependent on a static subcase.The parameters STRESSK, SPINK and FOLLOWK can optionally be defined on the NLCNTL bulkentry to request the additional stiffness terms computed in the previous static subcase.

In addition to axisymmetric elements, the plane stress and the new chocking elements can also beincluded with the Fourier normal modes subcase. In the Fourier normal modes subcase, Gausspoint locations on the chocking element use the axisymmetric Fourier formulation if the location isconsidered chocked. That is, it includes stiffness in the radial, axial and theta degrees-of-freedom,and all degrees-of-freedom are represented using harmonic terms of a Fourier series. To beconsidered chocked, the loads in a previous static subcase should result in the chocked condition,and the consecutive Fourier normal modes subcase should be defined as sequentially dependent. Bydefault, all Gauss locations on the chocking elements are considered unchocked in a Fourier normalmodes subcase, and use the plane stress element formulation.

For grid points which are defined on the rotation axis, in addition to any conditions that you defined,NX Nastran automatically applies the following SPC and MPC conditions during the solution.

• For the harmonic index k=0, NX Nastran fixes DOF 1, 2.




• For the harmonic index k=1, NX Nastran fixes DOF 3, and it creates the MPC condition Ux = Uyfor the cosine terms, and the MPC condition Ux = -Uy for the sine terms.

Cyclic clocking and normalization

As a result of the inherent symmetry with the Fourier modal solution, modes occur in pairs for allharmonics where k>0. Once NX Nastran computes the normal modes, it uses the initially computeddisplacement vectors to do the following:

• The software clocks the eigenvector solution to the primary sector. This clocking ensures that, forthe first mode in a mode pair, the maximum nodal displacement occurs on the primary sector.

• If you have selected either the AFNORM or DISP normalization options, the softwarerenormalizes using the maximum displacement relative to all sectors.

The clocking and normalization procedure is as follows.

The Fourier cosine and sine terms are combined into new global vectors such that:

and .

The global displacement vectors and in a single mode are orthogonal to each other. In

addition, from one mode in a pair is related to from the same pair.

For a travelling wave with equal amplitude in any mode pair, every grid point traverses an ellipse inthree dimensional space. The maximum resultant displacement is the major axis of the ellipse. For agrid point i, the maximum resultant displacement is computed as follows.

is the cosine displacement vector (three components) at a specific grid point.

is the sine displacement vector (three components) at a specific grid point.

The software computes the following using the cosine and sine vectors:

The resultant displacement at each grid point i is computed as:

The software determines the grid point with the maximum resultant displacement. For this grid pointii, the phase angle is computed as:




This phase angle will be used to clock the displacements to the primary sector.

The maximum displacement found at grid point ii is used to compute the normalization factor:

• For AF normalization, the factor is computed as:

where,

ω is the frequency for the mode, and

AFNORM is the parameter setting PARAM, AFNORM which defaults to 1.0.

For the modes considered as rigid body modes, the software sets ω = 1 when computing the AFnormalization factor. The software considers a mode to be a rigid body mode if its frequency isbelow the value of the new parameter AFZERO (default=1.0 hz).

• For unit (MAX) normalization, the factor is computed as:

• For mass (MASS) normalization, the factor f=1.0 is used since the eigenvector was already massnormalized when the modes were computed initially.

The cosine and sine components are then clocked based on the computed values of .

The Fourier symmetry or antisymmetry components for each mode are then reset to the new values:

Fourier normal modes subcase input summary

• The ANALYSIS=FOURIER case control command should be defined in the subcase in which youare requesting the new Fourier normal modes subcase in SOL 401.




• The HARMONICS case control command requests the specific harmonics in which modes willbe computed. The SET entry then lists the harmonic numbers to be computed, including "0" torequest the zeroth harmonic. Since there is an infinite number of harmonics in the Fourier normalmodes analysis, the describer "ALL" is not supported in the ANALYSIS= FOURIER subcase.

• The HOUTPUT case control command optionally requests the harmonics to output modes. "ALL"requests output for every harmonic requested on the HARMONICS command. An integer can bedefined to select the SID of a SET bulk entry listing the harmonic numbers to be output. TheseIDs typically represent a subset of the IDs requested on the HARMONICS command. The C, S,C*, and S* describers on the HOUTPUT command are not supported by SOL 401.

• The METHOD case control command selects the EIGRL bulk entry, which then defines theeigenvalue solution options. For example, the lower and upper frequency ranges and the numberof modes.

• As a result of the inherent symmetry in the Fourier modal solution, mode pairs exist for harmonicnumbers k > 0. The software automatically outputs the mode pairs for these subcase typesfor the modes requested with the EIGRL entry. For example, if you request 10 modes on theEIGRL entry:

For harmonic index 0, 10 modes are computed.

For harmonic index > 0, 20 modes are computed (10 distinct modes).

This behaviour is consistent for modes requested with the OMODES case control command. Seethe remarks on the OMODES command for details.




HARMONICS

Requests Solution Harmonics

Requests the solution harmonics for cyclic symmetry and axisymmetric models insolutions 114, 115, 116, 118, and 401.

FORMAT:

EXAMPLES:HARMONICS=ALLHARMONICS=32

DESCRIBERS:

Describer Meaning

ALL All harmonics will be used.

n Set identification number. The referenced SET lists the harmonicnumbers to use. (Integer>0)

REMARKS:1. Either HARMONICS=ALL or HARMONICS=n is required in cyclic symmetry

solutions 114, 115, 116, 118, and in a ANALYSIS=CYCMODES subcase in SOL401.

HARMONICS=n is required in a ANALYSIS=FOURIER subcase in SOL 401.HARMONICS=ALL is not supported in a ANALYSIS=FOURIER subcase.

2. n is the ID of a SET command which lists the harmonic numbers. For example,

...HARMONICS = 101SET 101 = 3,5,8,12...

3. The HOUTPUT case control command can be used to request the harmonicnumbers for results output.




HOUTPUT

Harmonic Output Request

Requests harmonic output for cyclic symmetry and axisymmetric models in solutions114, 115, 116, 118, and 401.

FORMAT FORSOLS 114, 115,

116, 118:

FORMAT FORSOL 401:

EXAMPLES:HOUTPUT=ALLHOUTPUT=5

DESCRIBERS:

Describer Meaning

ALL All harmonics will be output.

k Set identification number. The referenced SET lists the harmonicsfor output. (Integer>0)

C, S, C*, S* Harmonic coefficients for SOLs 114, 115, 116, 118. Not supportedby SOL 401.See Remark 4.

REMARKS:1. k is the ID of a SET command which lists the harmonic numbers for output. For

example,

...HOUTPUT = 101SET 101 = 3,5,8,12...

2. HOUTPUT=ALL requests output for all harmonics specified on the HARMONICScommand.

3. In SOLs 114, 115, 116, 118, either the HOUTPUT or NOUTPUT command isrequired to obtain data recovery in cyclic symmetry analysis.

In SOL 401, the HOUTPUT command is required to obtain harmonic data recoveryin a ANALYSIS=CYCMODES or ANALYSIS=FOURIER subcase.

4. In SOLs 114, 115, 116, 118, C and S correspond to the cosine and sine coefficientswhen the STYPE field is ROT or AXI on the CYSYM Bulk Data entry. C, S, C*,




and S* correspond to the cosine symmetric, sine symmetric, cosine antisymmetric,and sine antisymmetric coefficients respectively, when the STYPE field is DIH onthe CYSYM Bulk Data entry.

Parallel solution options with SOL 401Normal modes

Similar to a SOL 103 normal modes analysis, the GDMODES and RDMODES solution methods canbe used with the SOL 401 normal modes subcase (ANALYSIS=MODES). The commands to enableGDMODES and RDMODES in SOL 401 are the same as for a SOL 103 normal modes analysis.See the NX Nastran Parallel Processing Guide.

The following normal modes performance examples demonstrate.

For the following example, the model included about 2.5 million degrees-of-freedom and the runsutilized all cores of a 16-core processor workstation. The Lanczos run used SMP=16, and theGDMODES run used a DMP=4 and SMP=4 combination.

Normal modes Lanczos (SMP=16) GDMODES (DMP=4, SMP=4)Elapsed time 269 seconds 152 seconds

For larger models, normal modes analysis can benefit from the distributed parallel RDMODES. Forthe following example, the model included about 18.8 million degrees-of-freedom with a request of40 modes. RDMODES with DMP=4 and SMP=4 reduced about 25% of the elapsed time in normalmodes calculation.

Normal modes Lanczos (SMP=16) RDMODES (DMP=4, SMP=4)Elapsed time 74 minutes 52 minutes

Cyclic modes and Fourier modes

The cyclic normal modes subcase (ANALYSIS=CYCMODES) and the Fourier normal modes subcase(ANALYSIS=FOURIER) can take advantage of the DMP solution method. The modal solution for therequested harmonics are split among the processors as evenly as possible. The modes for eachharmonic are calculated on the assigned processor.

The following cyclic normal modes performance example demonstrates.

• Model included 235,000 grids and 19,400 elements.

• 5 harmonics were requested. The harmonic IDs are 0, 1, 2, 3, and, 4.

• DMP=4 was requested. The head processor computed the normal modes for harmonic IDs 0 and1. The normal modes solution for harmonic IDs 2-4 were assigned to the remaining 3 processors.

CYCMODES Sequential Run (without DMP) DMP=4Elapsed time 46 minutes 13 minutes




Bolt preloadNew preload subcase type

In previous releases, a bolt preload subcase was designated by the ANALYSIS=STATICS andBOLTLD=n case control commands.

In NX Nastran 11, a bolt preload subcase requires the ANALYSIS=PRELOAD and BOLTLD=ncommands. A subcase with ANALYSIS=STATICS and the BOLTLD=n will now cause a fatal error.You will need to modify the subcase to replace ANALYSIS=STATICS with ANALYSIS=PRELOADto run the model in NX Nastran 11.

Service loads in a preload subcase

A service load is any load that is not a bolt preload and thermal load. Service loads are selectedwith the LOAD=n or DLOAD=n case control commands. Thermal loads are selected with theTEMP(LOAD)=n or DTEMP(LOAD)=n. Bolt preloads are selected with the BOLTLD=n case controlcommand.

You cannot define service loads directly in a bolt preload subcase, although a sequentially dependentbolt preload subcase now includes a service load used in a previous static subcase.

For example, if a dload=n is defined in the previous static subcase, then this definition is used in theprevious subcase and in the bolt preload subcase. If the previous subcase does not include a serviceload, but a dload=n is defined globally, then this definition is used in the previous subcase andin the bolt preload subcase.

Service loads can change the strain and the resulting axial bolt force by either compressing orseparating the bolted joint. The ability to include service loads in a bolt preload subcase is useful,for example, if you define your bolt preloads in the first subcase, then define your service loads ina single or in consecutive subcases, then reapply the bolt preloads. The software maintains yourservice loads while recomputing the bolt strains needed to satisfy your requested bolt forces.

Multiple bolt preload subcases

In NX Nastran 10, you could define only a single bolt preload subcase. As a result, bolt strain wascomputed for all of the bolts simultaneously in that subcase. The single bolt preload subcase did notneed to be the first subcase, and it could be defined as sequentially dependent or nonsequentiallydependent.

In NX Nastran 11, you can define multiple bolt preload subcases. You can define them as sequentiallydependent or nonsequentially dependent, and can optionally include the new bolt preload sequencedescribed below. As a result, you can now define bolt preload subcases to apply or remove boltforces in any sequence. For example, you can now apply a tightening sequence of many boltsbefore and even after service loads are applied.

Bolt preload specified by displacement or strain

When a bolt preload is defined as an axial load, the software computes the axial strain required tosatisfy the requested preload.

In NX Nastran 11, you can enter the axial strain or axial displacement directly using the new BOLTFRCbulk entry. For example, you can apply bolt strains which were computed in a previous solution.

You use the TYPE field on the BOLTFRC entry to enter the optional load, strain, or displacement input.




• To define the preload as an axial displacement, set TYPE=DISP. The software converts the axialdisplacement to an axial strain using the bolt length. The software can compute the bolt lengthautomatically, or you can optionally define the bolt length on the BOLTFRC entry.

• To define the preload as an axial force, set TYPE=LOAD. The software computes the axialstrain required to satisfy this preload force.

• To define the preload as an axial strain, set TYPE=STRAIN.

For any of these definitions, the software stores and reapplies the resulting axial preload strain inconsecutive preload steps, and in consecutive sequentially dependent static subcases. The softwarecontinues to reapply the axial preload strain until you either define a new bolt preload step or subcasewhich redefines the axial preload strain, or you define a nonsequentially dependent subcase.

Note that in consecutive steps and subcases, the total axial strain on a preloaded bolt includes theaxial preload strain, along with strain resulting from any other loads you apply, including preloadson neighboring bolts.

Bolt preload sequence

In NX Nastran 10, the software computed the strains for all the bolts selected in a single bolt preloadsubcase, simultaneously.

In NX Nastran 11, you can define multiple subcases to sequence bolt preloads. In addition, youcan use the new BOLTSEQ bulk entry to optionally define a sequence of preload steps in a singlesubcase. The BOLTSEQ bulk entry is selected in a subcase with the BOLTLD case control command.

Each preload step in the sequence includes the following:

• The step number in the sequence.

• The ID of a BOLTLD and BOLTFRC bulk entry to select the bolts and the preloads.

• The optional number of increments (Ninc) on the BOLTSEQ entry. You define this number toincrement the bolt preloads, which helps both to reduce the bolt preloading steps and to solveconvergence problems.

Note that the number of increments (Ninc) on the TSTEP1 entry in a bolt preload subcaseincrements only temperature loads and contact offsets. It does not increment the bolt preloads. Ifyou set the Ninc on both the BOLTSEQ entry and the TSTEP1 entry, all of the increments fortemperature loads and contact offsets will occur in the first bolt preload increment.

Each sequence step results in an axial bolt strain. The software then applies the resulting axial strainas an initial condition in consecutive preload steps, and in consecutive sequentially dependentstatic subcases.

Bolt preload results

The new BOLTRESULTS case control command is available in SOL 401 to request the bolt force andthe axial strain output. The output is relative to the coordinate system used to define the bolt axis,and includes the axial, bending moment, shear forces, and axial strain. You can request the output tothe .f06, .op2, and .pch files. In the .op2 file, the data is written to the new OBOLT1 data block.

The bolt force output is a summation of the forces across the bolt cross section. The bolt forcecomputation for each force component is similar to cutting the bolt at a point along the axis, thensumming the forces on the faces of one side of the cut. Although the total force components are




not computed on a per element basis, the constant force values computed for the bolt are writtento every element defining the bolt. The result of this is that each bolt displays as a constant forceinside a post processor.

Note: An issue related to strain output has been found late in the NX Nastran 11.0 release and will befixed in the NX Nastran 11.1 maintenance release. See Incorrect strain output for the description ofthe issue.

Bolt preload diagnostic messages in .f06

Bolt preload diagnostic messages are now written to the .f06 file. The new MSGLVLB parameter onthe NLCNTL bulk entry controls the message level. The MSGLVLB options are as follows:

MSGLVLB=0: Bolt summary messages are written to the .f06 file upon convergence.

MSGLVLB=1 (default): Bolt summary messages are written to the .f06 file at every bolt preloaditeration.

MSGLVLB=2: Bolt summary messages and load/tolerance messages are written to the .f06 file atevery bolt preload iteration.

The MSGLVLB 1 and 2 settings also output a table of bolt data showing the forces, moments andstrains per bolt. This is written only after all bolt preloads have converged.

Note: MSGLVLB=1 and MSGLVLB=2 require that the MSGLVL parameter, which is also defined onthe NLCNTL bulk entry, be set to 1 (default). If you define MSGLVL= 0, the software forces MSGLVLBto 0, even if you defined MSGLVLB=1 or MSGLVLB = 2.

The following examples demonstrate the MSGLVLB output options.

MSGLVLB = 0 – The following is output upon convergence.

----- BOLT COUNT ------ ----------- BOLT PRELOADING STATUS-----------ITERATION TOTAL PRELOADING WITHIN TOL ERROR TOL MAX ERROR4 1 1 1 1.00E-03 8.80E-05

MSGLVLB = 1 (Default) – The following is output at every bolt iteration.


MSGLVLB = 2 – The following is output at every bolt iteration.


TARGET ACTUAL ERROR WITHINBOLT ID PRELOAD PRELOAD RATIO TOL101 2.00E+08 7.58E+07 6.21E-01 -

MSGLVLB, 1 and 2 – The following is output upon convergence

-----BOLTS SUMMARY UPON CONVERGENCE-----BOLT ID AREA PRELOAD AXIAL SHEAR1 SHEAR2 MOM1 MOM2 STRN101 1.00E+02 2.00E+08 2.00E+08 -3.63E-07 1.10E-06 -2.79E+08 -2.79E+08 2.64E-02

Zero bolt preload force




The option to define a zero bolt preload force is now available. The zero preload is useful, forexample, to predict the plastic axial bolt strain after you apply bolt preloads, service loads, and thenunload the bolt to a zero axial force condition.

When you define a zero bolt preload force, the software iterates on the bolt strain until the zero boltforce condition is satisfied. The software checks for convergence by checking if P/AE < ZERBOLT,

where:

• P is the resulting axial bolt force from an applied axial strain value,

• A is the area of the bolt cross section,

• E is the modulus of the material selected for the elements on the bolt,

• ZERBOLT is a new parameter on the NLCNTL bulk entry and defaults to 1.0E-7.

Note that the software considers a bolt preload force to be zero when F/AE < ZERBOLT, where Fis the preload force you requested on the BOLTFRC entry. It is possible that you did not define apreload of 0.0, yet A and E are large enough for the software to determine that the zero preloadconvergence checking should be used.

If the software determines that your requested preload is nonzero, it uses the EPSBOLT parameter todetermine convergence, and not ZERBOLT. See the remarks on the NLCNTL bulk entry.

New constant time subcaseIn NX Nastran 10, all bolt preload subcases required Tend1=0.0 on the TSTEP1 bulk entry.

In NX Nastran 11, a sequentially dependent bolt preload subcase can include a TSTEP1 bulk entrydefined with a Tend1 which is the same as the start time for that subcase.

Although the bolt preload subcase does not use time to increment bolt preloads, this enhancementprovides the ability to continue a time sequence through an intermediate bolt preload subcase. Aconsecutive sequentially dependent static subcase can then continue the time sequence to incrementservice loads.

A nonsequentially dependent bolt preload subcase still requires a TSTEP1 bulk entry defined withTend=0.0.

MISFBLT parameterThe new MISFBLT parameter is available on the NLCNTL bulk entry to limit the bolt strain from onepreload increment to the next. It is useful, for example, if you model a bolted joint with a gap condition.

The bolt preload algorithm increments the bolt strain as the joint compresses. When a gap is present,before the joint is compressed, the axial bolt force is relatively low. As a result, the preload algorithmincreases the strain increments. Once the gap is closed and the joint begins to compress, the boltand contact forces change quickly, possibly causing the contact conditions to destabilize. By limitingthe bolt preload strain increments, you can reduce the chance of destabilization, and ultimatelyhelp achieve convergence.

At the start of a bolt preload solution, the software uses your requested preload force and the boltgeometry to estimate a bolt strain. The estimated strain (εes) is computed with the assumption thateverything is rigid except for the bolt. The software then computes the maximum allowable strainincrement using the new MISFBLT parameter.

Δεmax = εes * MISFBLT




At each preload increment, the software compares Δεmax with the next computed preload incrementΔεi+1. The software uses the smaller of the two at each preload increment.

Incorrect strain output

The following issue related to strain output has been found late in the NX Nastran 11.0 release andwill be fixed in the NX Nastran 11.1 maintenance release.

When multiple bolts are preloaded in a sequence, the output requested with the BOLTRESULTScommand will show an incorrect strain value output for all but the last bolt. In addition, when bolts areloaded in a previous subcase and the BOLTRESULTS output is requested in the current subcase, thestrain value for the bolts preloaded in the previous subcases will be incorrect in the BOLTRESULTSoutput. Note that all of the bolts are being preloaded correctly and the issue is only with the valueof the strain output in the f06 and op2 files. For example, a bolt loaded at 1000N will be loadedcorrectly with 1000N even though the strain value column shows the incorrect value. A query of theaxial force values in the BOLTRESULTS output will demonstrate the correct bolt force. The strainat which the bolt is being held in subsequent subcases is also correct despite the incorrect strainreported in the BOLTRESULTS output. As a result, models with bolts do produce correct behaviourthroughout the entire solution and produce expected results, except for the strain column in theBOLTRESULTS output.




BOLTSEQ

Specifies a bolt preload sequence in SOL 401.

Specifies a bolt preload sequence.FORMAT:

1 2 3 4 5 6 7 8 9 10

BOLTSEQ SID

S_NOi B_IDi NINCi

EXAMPLES:

BOLTSEQ 100

1 11 3

2 22 2

FIELDS:

Field Contents

SID Bolt preload set identification number (Integer; No default)

S_NOi Sequence order number for the BOLTLD, BOLTFOR, and BOLTFRCID’s to be applied. (Integer; No default)

B_IDi SID of BOLTLD, BOLTFOR, or BOLTFRC bulk entries defining a boltpreload. (Integer; No default)

NINCi Number of increments in which to ramp up the bolt preload defined inBOLTLD, BOLTFOR, or BOLTFRC entries. (Integer; Default = 1)

REMARKS:1. BOLTSEQ is only supported in SOL 401.

2. A bolt preload force equal to 0.0 is supported. The zero preload is useful, forexample, to predict the residual axial bolt strain after applying a bolt preload,applying service loads, then finally unloading the bolt to the zero axial forcecondition.

3. The S_NO values must be sequential.

4. If NINCi is defined on the BOLTSEQ entry, that value overrides the value definedon the TSTEP1 increment.

5. The parameter MSGLVLB on the NLCNTL bulk entry controls the printed boltpreload output to the .f06 file.

6. The following rules apply when BOLTFOR, BOLTFRC, BOLTLD, or BOLTSEQbulk entries are defined using the same SID in SOL 401.

• Multiple BOLTFOR and BOLTFRC entries with the same SID can bereferenced by the BOLTLD case control command directly, and by the




BOLTSEQ and BOLTLD bulk entries. The software will combine and applythem together.

• If a BOLTSEQ entry is referenced by the BOLTLD case control command,BOLTFOR, BOLTFRC, and BOLTLD entries with the same SID as theBOLTSEQ are only used if they are referenced in a sequence defined onthe BOLTSEQ entry.

• If a BOLTLD bulk entry is referenced by the BOLTLD case control command orby the BOLTSEQ bulk entry, BOLTFOR and BOLTFRC entries with the sameSID as the BOLTLD entry are used if they are referenced on the BOLTLD entry.

• Only one BOLTSEQ entry can be referenced. The software will fatal if multipleBOLTSEQ entries with the same SID are referenced.

• Only one BOLTLD entry can be referenced. The software will fatal if multipleBOLTLD entries with the same SID are referenced.

7. You can define a bolt preload as an axial force, displacement, or strain on theBOLTFRC bulk entry. For any of these definitions, the result is an axial preloadstrain in which the software will store, and reapply in consecutive preload steps ina sequence, and in consecutive sequentially dependent subcases. The softwarecontinues to reapply the axial preload strain until you either define a new boltpreload step or subcase which redefines the axial preload strain, or you define anonsequentially dependent subcase.

Note that in consecutive steps and subcases, the total axial strain on a preloadedbolt includes the axial preload strain, along with strain resulting from any otherloads you apply, including preloads on neighboring bolts.

8. When a bolt preload is defined as a force, the software computed axial preloadstrain includes the effects of any other loads you included in the preload step(thermal loads, contact forces, preloaded bolts from a previous preload step, andconditions from a previous subcase). For example, if you compare the resultsfrom a solution with only bolt preloads defined with the results from the samemodel with the addition of thermal loads and contact, the bolt force will be thesame, but the final bolt strain needed to achieve the bolt force will be different.




BOLTFRC

Defines bolt preload force, displacement, or strain in SOL 401.

Defines bolt preload force, displacement, or strain in SOL 401.

FORMAT:

1 2 3 4 5 6 7 8 9 10

BOLTFRC SID TYPE D LEN

B1 B2 B3 B4 B5 B6 B7 B8

B9 THRU B10

B11 B12 -etc-

EXAMPLE:

BOLTFRC 4 STRAIN .0025

1 4 6 9 10 26 32 34

37 43 51

FIELDS:

Field Contents

SID Bolt preload set identification number (Integer; No default)

TYPE TYPE=DISP, STRAIN, or LOAD (Character; No default)

D Preload value. (Real; No default)

When TYPE=DISP, D is a preload displacement.

When TYPE=STRAIN, D is a preload strain.

When TYPE=LOAD, D is a preload force.

LEN Optional bolt length when TYPE=DISP. (Real; Software automaticallycomputes the length if LEN is undefined.)

Bi Bolt identification numbers (BID) defined by BOLT bulk entries.(Integer>0 or use “THRU” option. For “THRU” option, B7<B8)

REMARKS:1. BOLTFRC is only supported in SOL 401.

2. A bolt preload force equal to 0.0 is supported. The zero preload is useful, forexample, to predict the residual axial bolt strain after applying a bolt preload,applying service loads, then finally unloading the bolt to the zero axial forcecondition.

3. The following rules apply when BOLTFOR, BOLTFRC, BOLTLD, or BOLTSEQbulk entries are defined using the same SID in SOL 401.




• Multiple BOLTFOR and BOLTFRC entries with the same SID can bereferenced by the BOLTLD case control command directly, and by theBOLTSEQ and BOLTLD bulk entries. The software will combine and applythem together.

• If a BOLTSEQ entry is referenced by the BOLTLD case control command,BOLTFOR, BOLTFRC, and BOLTLD entries with the same SID as theBOLTSEQ are only used if they are referenced in a sequence defined onthe BOLTSEQ entry.

• If a BOLTLD bulk entry is referenced by the BOLTLD case control command orby the BOLTSEQ bulk entry, BOLTFOR and BOLTFRC entries with the sameSID as the BOLTLD entry are used if they are referenced on the BOLTLD entry.

• Only one BOLTSEQ entry can be referenced. The software will fatal if multipleBOLTSEQ entries with the same SID are referenced.

• Only one BOLTLD entry can be referenced. The software will fatal if multipleBOLTLD entries with the same SID are referenced.

4. A BID can only be referenced once in a subcase. This includes BID refererencedon a single BOLTFOR or BOLTFRC entry, and BID on multiple BOLTFOR orBOLTFRC entries.

5. You can define a bolt preload as an axial load, displacement, or strain. For anyof these definitions, the result is an axial preload strain in which the software willstore, and reapply in consecutive preload steps in a sequence, and in consecutivesequentially dependent subcases. The software continues to reapply the axialpreload strain until you either define a new bolt preload step or subcase whichredefines the axial preload strain, or you define a nonsequentially dependentsubcase.

Note that in consecutive steps and subcases, the total axial strain on a preloadedbolt includes the axial preload strain, along with strain resulting from any otherloads you apply, including preloads on neighboring bolts.

6. When a bolt preload is defined as a load, the software computed axial preloadstrain includes the effects of any other loads you included in the preload step(thermal loads, contact forces, preloaded bolts from a previous preload step, andconditions from a previous subcase). For example, if you compare the resultsfrom a solution with only bolt preloads defined with the results from the samemodel with the addition of thermal loads and contact, the bolt force will be thesame, but the final bolt strain needed to achieve the bolt force will be different.




BOLTRESULTS

Requests bolt results output in SOL 401.

Requests bolt results output in SOL 401.FORMAT:

EXAMPLES:

BOLTRESULTS=ALLBOLTRESULTS(PRINT,PUNCH)=17

DESCRIBERS:

Describer Meaning




ALL Requests output for all grid points.

n Set identification number of a previously appearing SET command.The referenced SET lists the bolt IDs in which output is requested.(Integer>0)

NONE Output is not computed.

REMARKS:1. The BOLTRESULTS case control is only supported in SOL 401.

2. The output requested with the BOLTRESULTS case control command includes theaxial force, bending moment, the shear forces, and the axial strain for each bolt IDlisted on the SET command. The output is computed relative to the coordinatesystem used to define the bolt axis. The computed results for a bolt are written toeach element defining that bolt. For example, if you display the bending momentin a post processor, the bolt will display as a constant.

Sliding glueA new sliding glue option is available for both surface-to-surface and edge-to-edge glue by definingthe new parameter setting SLIDE=1 on the BGPARM entry. Sliding glue includes a normal stiffness,but no tangential stiffness. The new option is supported for GLUETYPE=2 (default).

Any gaps between the glue edges and surfaces are preserved as sliding occurs. Since smalldisplacement assumptions exist for glue definitions, rotations are not accounted for, and only




infinitesimal sliding is supported. When the sliding glue and large displacements are turned on, theglue orientations update when sliding occurs, but the glue pairing does not update.

You can request slide distance output using the new SEPDIS describer on the BGRESULTS casecontrol command. The slide distance represents the tangential distance traveled by the sourceand target grids relative to each other. The total and incremental slide distance output is written inthe basic coordinate system on grid points for both the source and target regions. The total slidedistance is the vector sum of the incremental slide distances from all time steps. If a subcase issequentially dependent, the total slide distance also includes the total slide distance from a previousstatic subcase.




BGPARM

Glue Parameters

Control parameters for the glue algorithm.FORMAT:

1 2 3 4 5 6 7 8 9 10BGPARM GSID Param1 Value1 Param2 Value2 Param3 Value3

Param4 Value4 Param5 Value5 -etc.-

EXAMPLE:

BGPARM 4 INTORD 2 PENN 10.0 PENT 10.0REFINE 0

FIELDS:

Field Contents

GSID Glue set ID. Parameters defined in this command apply to glue setGSID defined by a BGSET entry. (Integer > 0)

PARAMi Name of the BGPARM parameter. Allowable names are given in theparameter listing below. (Character)

VALUEi Value of the parameter. See below for the parameter listing. (Realor Integer)

Table 5-12. BGPARM Parameters:

Name Description

GLUETYPE* Selects the glue formulation for surface-to-surface glue. (Default=2)See Remark 2. Edge-to-surface and edge-to-edge glue pairs alwaysuse GLUETYPE=2.

1 - Normal and tangential springs will be used to define theconnections. See Remark 7.

2 - A “weld like” connection will be used to define the connections.

PENTYP* Changes how glue element stiffness and “conductance” arecalculated. (Default=1) See Remark 2.

PENN* Penalty factor for normal direction when GLUETYPE=1.(Default=100) See Remarks 1 and 2.

PENT* Penalty factor for transverse direction when GLUETYPE=1.(Default=100) See Remarks 1 and 2.

PENGLUE* Penalty factor when GLUETYPE=2. (Default=1) See Remarks 1and 2.




Table 5-12. BGPARM Parameters:

Name Description

INTORD Determines the number of glue points for a single element face on thesource region. Edge-to-surface glue pairs always use INTORD=3.

1 - Low order

2 - Medium order (default)

3 - High order

REFINE Requests that the software refine the mesh on the source regionduring the solution to be more consistent with the target side mesh.

0 - Refinement does not occur.

2 - Refinement occurs. (default).

PREVIEW Requests the export of a bulk data representation of the elementedges and faces where glue elements are created. See Remark 6.

0 - The bulk data export does not occur (default).

1 - The bulk data export occurs.

ESOPT Changes the edge-to-surface glue stiffness.Shell theory does not account for changes in shell thickness ornormal strains perpendicular to the plane of the shell element. TheESOPT parameter gives you a choice of how to handle the linking ofthe zero normal strains which exist in the shell element associatedwith the edge, to the surface being glued.

0 - Strains in the plane of the surface being glued in the directionperpendicular to the edge are not constrained by the glue stiffness(default).

1- Strains in the plane of the surface being glued in the directionperpendicular to the edge are constrained by the glue stiffness.

SLIDE Requests the sliding glue in SOL 401. Sliding glue includes normalstiffness but no tangential stiffness. Gaps between the glued surfacesare preserved as sliding occurs.

0 - Sliding glue is off (default).

1 - Sliding glue is on.

* Can be defined on local BGPARM entries. The BGPARM bulk entries associated toindividual BGSET bulk entries, which are then combined with a BGADD bulk entry,define local parameters. A local parameter definition overrides a global definition.

REMARKS:1. The following table summarizes the parameters and solution support for the

different glue types.




Glue Type Parameter and Solution Support

Surface-to-SurfaceGlue

All parameters except ESOPT are supported.Surface-to-surface glue is supported in structural solutions,in heat transfer solutions 153 and 159, and for gluing fluidsurfaces to other fluid surfaces in a coupled acousticsanalysis. In a coupled acoustics analysis, GLUETYPE,PENTYP, and PENT are all ignored, and PENN is describedin Remark 3.

Edge-to-SurfaceGlue

Only the parameters PENTYPE, PENGLUE, PREVIEW, andESOPT are supported. GLUETYPE=2 formulation is alwaysused.Edge-to-surface glue is supported in structural solutionsexcept solution 401, and in heat transfer solutions 153 and159.

Edge-to-Edge Glue

Only the parameters PENTYPE, PENGLUE, and PREVIEWare supported. GLUETYPE=2 formulation is always used.Edge-to-edge glue is supported in structural solutions, andin heat transfer solutions 153 and 159.

2. GLUETYPE has unique penalty factor inputs in structural solutions and in heattransfer solutions 153 and 159. These inputs and units are described below.

GLUETYPE=2(default forstructuralsolutions)

The glue penalty stiffness is defined by PENGLUE. A physicalinterpretation of this glue connection is a beam like element.(Solutions 153 and 159 - Heat transfer analysis always usesGLUETYPE=1)

PENTYP=1(default)

PENGLUE is a unitless scale factor of the beamlike element stiffness. The averaged modulus ofthe elements associated with the source sideregion are used when computing this stiffness.

Structuralsolutions:

PENTYP=2 PENGLUE is the beam like element modulus (E)with units of Force/Area.

Solutions 153and 159: Always uses GLUETYPE=1.

GLUETYPE=1 The glue penalty stiffness is defined by PENN and PENT.Structural solutions: PENN and PENT haveunits of 1/(length), and the glue elementstiffness is calculated by K = e*E*dA where erepresents PENN or PENT, E is an averagemodulus (averaged over elements associatedwith the source side region), and dA is area. Aphysical interpretation is that it is equivalent tothe stiffness of a rod with area dA, modulus E,and length 1/e.

PENTYP=1

Solutions 153 and 159: PENT is ignored. PENNhas the units of 1/(length), and “conductance” atthe glue connection is calculated as

C = e*kavg*dA*100




where e represents PENN, kavg is an averageof the thermal conductivity (k) values definedon the MAT4 entries (averaged over elementsassociated with the source side region), and dAis area.

A physical interpretation is that it is equivalent tothe axial "conductance" of a rod with area dA,conductivity kavg, and length 1/e.Structural solutions: PENN and PENT becomea spring rate per area Force/(Length x Area),and the glue element stiffness is calculated asK=e*dA. The spring rate input is a more explicitway of entering glue stiffness since it is notdependent on the average modulus.PENTYP=2Solutions 153 and 159: PENT isignored. PENN has the units of (thermalconductivity*length)/area, and the “conductance”at the glue connection is calculated as C = e*dA.Another term for e is heat flux.

3. When gluing fluid surfaces to other fluid surfaces for a coupled acoustics analysis,GLUETYPE, PENTYPE, PENT are all ignored, and PENN is used to calculate theacoustics penalty matrix K:

where e is PENN, ρ is the average density of all fluid elements in the model, anddA is the surface area. The K matrix for an acoustic element is defined by

For a small fluid column (tube of length L and cross-sectional area dA), the Kmatrix can be written as

Therefore, the penalty factor PENN (e) can be interpreted as 1/L.

Edge-to-surface glue pairs can not be used as acoustics glue connections.

4. BGPARM is not supported in SOL 601, although glue definitions (BGSET) aresupported.

5. The BGPARM bulk entry is not required. When it is not present, the default valuesare used. At least one parameter should be defined when a BGPARM entry exists.

6. Setting the PREVIEW parameter to “1” requests a bulk data representation of theelement edges and faces where glue elements are created. The software will writea bulk data file containing dummy shell element entries for face locations, anddummy PLOTEL entries for edge locations. Dummy GRID, property and material




entries are also written. You can import the file into a preprocessor to display bothsource and target glue locations. The preview file has the naming convention

<input_file_name>_glue_preview_<subcaseid>_<gluesetid>.dat

7. SOL 401 only supports GLUETYPE = 2. If you request GLUETYPE=1, thesoftware will continue the solution using GLUETYPE=2.




BGRESULTS

Glue Result Output Request (SOLs 101, 103, 105, 401, 601)

FORMAT:

EXAMPLES:BGRESULTS=ALLBGRESULTS(FORCE,PLOT)=ALLBGRESULTS(TRACTION,FORCE,PLOT)=ALL

DESCRIBERS:

Describer Meaning

TRACTION Glue normal traction (scalar) and in-plane glue tractions (vectorin basic coordinate system) are output for each glue grid point.Traction units are force per area.

FORCE Glue force vector is output for each glue grid point.

SEPDIS For SOL 401 only. Requests the final separation distance, andthe total and incremental slide distance for grids on the sourceand target regions.

PRINT The printer will be the output medium.

PLOT Computes and puts glue results in OP2 file only.

PUNCH The punch file is the output media.

SORT1 Output will be presented as a tabular listing of grid points for eachload, frequency, eigenvalue or time, depending of the solutionsequence.

SORT2 Output will be presented as a tabular listing of load,frequency ortime for each grid point (not supported for SOL 401).

ALL Glue results at all contact grid points will be output.

NONE Glue results will not be output.

n Set identification of a previously appearing SET command. Onlyglue grid points with identification numbers that appear on thisSET command will be output. (Integer>0)

REMARKS:1. The glue traction request is supported in solutions 101, 103 (but only for a static

preload subcase if present), 105, and 401 (static subcase only). The glue results




from SOL 105 are a result of the applied static loads which are not necessarily theloads at which buckling occurs.

2. Sliding glue can be requested in SOL 401 with the parameter setting SLIDE=1on the BGPARM entry. Sliding glue includes a normal stiffness, but no tangentialstiffness. When sliding glue is requested, the SEPDIS describer can be usedto request slide distance output. The slide distance represents the tangentialdistance traveled by the source and target grids relative to each other. The totaland incremental slide distance output is written in the basic coordinate system ongrid points for both the source and target regions. The total slide distance is thevector sum of the incremental slide distances from all time steps. If a subcase issequentially dependent, the total slide distance will also include the total slidedistance from a previous static subcase. Any gaps between the glue edges andsurfaces are preserved as slidiing occurs.

REMARKSRELATED TO

SOLS 601 AND701:

1. Glue traction request is not support in SOL 601.

Contact improvementsNX Nastran 11 includes the following improvements for surface-to-surface and edge-to-edge contact.

• The automatically computed penalty factors have been increased to minimize penetration andrelative slip between contact pairs.

• The new AUTOSCAL and TANSCL parameters are now available on the BCTPARM bulk entry toscale the automatically computed normal and tangential penalty factors.

• The regularized Coulomb friction model is available for improved convergence. It is activated withthe new FRICMOD parameter on the BCTPARM bulk entry. The tangential stiffness is adaptivelyvaried as a function of contact pressure, friction coefficient, and a critical slip value.

• The option to do large sliding in a small deformation solution (PARAM,LGDISP,-1) is now available.Large sliding was already available for a large deformation solution (PARAM,LGDISP,+1). Youcan use the existing GUPDATE and GUPTOL parameters on the BCTPARM bulk entry to makethe request, and the software will update the contact conditions when large sliding occurs.

• When friction methods are requested in a sliding contact solution, an unsymmetric stiffnessmatrix can result. To improve the solution performance with the unsymmetric stiffness, newunsymmetric solvers are available. You can use the new USOLVER parameter on the NLCNTLbulk entry to select the unsymmetric solver.

• A contact set and any referenced parameter definitions can now change between subcases.For example, you can remove or add contact regions and pairs, and change contact settingsincluding parameters, from one static subcase to the next.

Note that if a subcase is sequentially dependent and it includes a new contact set, any contacttractions from a previous subcase will be used as an initial condition for the current subcase. Theprevious tractions define the initial condition for the newly formed contact elements.




• Contact offsets are defined with the OFFSET parameter on the BCRPARA bulk entry. Offsetshave the following improvements.

o You can now change the contact offset definition from one subcase to the next.

o The option to increment contact offsets is now available. For subcases which have aconstant time*, the software automatically increments the contact offset using the number ofincrements. The number of increments is defined with either the Ninc field on the TSTEP1entry, or with the Ninc field on the new BOLTSEQ entry.

Note that the number of increments also increments loads and temperatures. Theincrementing of the contact offsets, loads, or temperatures helps the solution converge byreducing the changes which occur in an increment.

*A constant time subcase has a TSTEP1 bulk entry defined with either Tend=0.0, or a Tendwhich is the same as the start time for that subcase.

o When a sequentially dependent subcase is defined with SEQDEP=YES, the final contactoffset from a previous subcase, if it exists, is included at the start of the current subcase. Thegoal is to help convergence when contact offsets change from one subcase to the next. Inthis case, the offset for the current subcase is now calculated as:

OFFSET = OC * LF + OP * (1 - LF) oxy _newline

where:

■ OC = Contact offset for the current subcase,

■ OP = Contact offset from a previous subcase,

■ LF = Load factor incremented in Ninc steps. Initial value is 1/Ninc and the final valueis 1.0.

o General recommendations for offset definitions:

- A separate subcase is recommended to resolve the contact offset.

- When bolt preloads and contact offsets are defined together, be aware that both can resultin axial bolt strain. If you do not want the contact offset to result in an additional bolt strain,model the contact offset with a slight gap.

• The contact state and stiffness computed in a statics subcase can be included in the new cyclicnormal modes and Fourier normal modes subcase types.

• The new CNTMDIV parameter on the NLCNTL bulk entry is available to define the number ofpermissible contact divergences before besection of the load step occurs. The default is nine.

• The new chocking element can be included in an edge contact region.

• The new FRICDLY parameter on the NLCNTL bulk entry can be used to delay contact friction fora single contact iteration to help alleviate convergence problems.

• You can now request improved contact messaging using the new MSGLVLC parameter on theNLCNTL bulk entry. The software prints the information pertaining to each contact pair at thestart of the solution.




CONTACT SUBCASE ID: 1CONTACT SET ID: 1NUMBER OF CONTACT PAIRS: 1NUMBER OF CONTACT FACES: 1800NUMBER OF CONTACT EDGES: 0NUMBER OF CONTACT ELEMENTS CREATED: 19818

CONTACT PAIR ID: 1SOURCE REGION ID: 2TARGET REGION ID: 1

CHARACTERISTIC LENGTH: 3.432384E-02NORMAL PENALTY FACTOR: 2.913427E+02NORMAL STIFFNESS: 5.826854E+08FRICTION COEFFICIENT: 0.000000E+00PENETRATION TOLERANCE: 3.432384E-04

Contact max penetration (PRATIO) and change in forces (RCTOL) are printed as part of theiteration summary. PRATIO is the ratio of max penetration in the current iteration for all pairs andthe corresponding penetration tolerance (PTOL) in that pair. In addition to global convergencecriteria being met, the PRATIO and RCTOL criteria should also be met for contact problems.




BCTPARM

Surface-to-Surface Contact Parameters (SOLs 101, 103, 111, 112, and 401)

Control parameters for the surface-to-surface contact algorithm.FORMAT:

1 2 3 4 5 6 7 8 9 10

BCTPARM CSID Param1 Value1 Param2 Value2 Param3 Value3

Param4 Value4 Param5 Value5 -etc-

EXAMPLE:

BCTPARM 1 PENN 10.0 PENT 0.5 CTOL 0.001

SHLTHK 1

FIELDS:

Field Contents

CSID Contact set ID. Parameters defined in this command apply to contactset CSID defined by a BCTSET entry. (Integer > 0)

PARAMi Name of the BCTPARM parameter. Allowable names are given in theparameter listing below. (Character)

VALUEi Value of the parameter. See Table 5-13 for the parameter listing.(Real or Integer)

Table 5-13. Primary parameters supported by SOLs 101, 103, 111, and 112:

Name Description

CTOL Contact force convergence tolerance. (Default=0.01)

MAXF Maximum number of iterations for a force loop. (Default=10)

MAXS Maximum number of iterations for a status loop. (Default=20)

NCHG Allowable number of contact changes for convergence. (Default=0.02).See Remark 3.




Table 5-13. Primary parameters supported by SOLs 101, 103, 111, and 112:

Name Description

INIPENE* Use when the goal is for a pair of contact regions to be initiallytouching without interference, but due to the faceted nature of finiteelements around curved geometry, some of the element edges orfaces may have a slight gap or penetration. See Remarks 7 and 8.

0 or 1 - Contact is evaluated exactly as geometry is modeled. Nocorrections will occur for gaps or penetrations (Default).

2 - Penetrations will be reset to a new initial condition in which thereis no interference.

3 - Gaps and penetrations are both reset to a new initial conditionin which there is no interference.

SHLTHK* Shell thickness offset flag.

0 - Includes half shell thickness as surface offset. (Default)

1 - Does not include thickness offset.

ZOFFSET Determines if the shell element z-offset is included in the contactsolution.

0 - Includes the shell z-offset when determining the contact surfaces(Default).

1 - Does not include the shell z-offset when determining the contactsurfaces.

Table 5-14. Primary parameters supported by SOL 401:

Name Description

CNTCONV Contact convergence criteria.

1 – The contact convergence criteria is based on PTOL. (Default)

2 – The convergence criteria is based on CTOL.





Name Description

PTOL* Contact penetration tolerance used when CNTCONV=1. If the contactpenetrations exceed the penetration tolerance, an extra augmentationloop is performed. If the penetrations are below this tolerance,the augmentation loop is considered converged. In addition, if theglobal solution convergence criteria is satisfied, then the time step isconsidered converged. (REAL≠0.0; Default = 0.01 *characteristiclength)

A positive value is scaled by the characteristic length computed forthe contact pair.

If a negative value is defined, the absolute value is used, but the valueis not scaled by the characteristic length.

CTOL Contact augmentation traction convergence used when CNTCONV=2.The augmentation loop convergence criteria can be based on tractionconvergence. The contact force ratio FRAT is determined as:

where k is the augmentation loop id. If FRAT < CTOL, the contactaugmentation loop is considered converged. (Default = 0.05)

RCTOL Iterative contact force convergence. (Default = 0.05; Real>0.0)

MAXS Maximum number of augmentation (outer) loops. If the augmentationloop has not converged in MAXS number of iterations, the solution willproceed to the next step if the global convergence criteria has beenmet. Setting MAXS=1 selects a pure penalty formulation. (Default= 20; INTEGER≥1)

INIPENE* Use when the goal is for a pair of contact regions to be touchingwithout interference, but due to the faceted nature of finite elementsaround curved geometry, some of the element edges or faces mayhave a slight gap or penetration. See Remark 8.

0 or 1 - Contact is evaluated exactly as the geometry is modeled. Nocorrections will occur for gaps or penetrations (Default).

2 - Penetrations will be reset to a new initial condition in which thereis no interference.

3 - Gaps and penetrations are both reset to a new initial conditionin which there is no interference.

INIPENE is applied when contact elements are initially created, andif they are recreated as a result of large displacement effects whenPARAM,LGDISP,1 is defined.





Name Description

OPNSTF* Open contact stiffness scale factor. The open contact stiffness iscomputed by OPNSTF * closed stiffness. (OPNSTF default = 1.0E-6)

OPNTOL* Open gap tolerance scale factor. The open contact stiffness (OPNSTF* closed stiffness) is applied to the contact elements that have a gapvalue less than or equal to OPNTOL * characteristic length, but greateror equal than GAPTOL * characteristic length. The contact elementstiffness is 0.0 if the gap is greater than OPNTOL * characteristiclength. (OPNTOL default = 1.0)

GAPTOL* Closed gap tolerance scale factor. The closed contact stiffness isapplied to the contact elements that have a gap less than GAPTOL *characteristic length. (Default = 1.0E-10)

NOSEP* No separation contact option.

NOSEP=0 (default): When contact stiffness is recomputed in aconsecutive nonlinear iteration, contact elements which are inactiveas a result of normal tractions=0.0 and no penetration, and whichhave a gap greater than GAPTOL * characteristic length will remaininactive in the consecutive iteration.

NOSEP=1: The open contact stiffness (OPNSTF * closed stiffness) isapplied to the inactive contact elements that have a gap value lessthan or equal to OPNTOL * characteristic length, but greater or equalthan GAPTOL * characteristic length. The contact elements with a gapgreater than OPNTOL * characteristic length remain inactive. Whilesliding is permitted with this option, the magnitude of the sliding canbe controlled by the tangential penalty factor. To define frictionlesssliding, set the coefficient of friction=0.0 or tangential penalty factor(PENT)=0.0. (Default=0)

GUPDATE Geometry update flag. (Default=0 when PARAM,LGDISP,-1;Default=2 for PARAM,LGDISP,1; INTEGER)

0 – Contact geometry updates will not be done during the analysis.

1 – Contact geometry updates occur when SLIP > (GUPTOL *Average element length).

2 - Contact geometry updates occur at the start of each step and whenSLIP > (GUPTOL * Average element length).

3 - Contact geometry updates occur once a step.

4 - Contact geometry updates occur every iteration.





Name Description

GUPTOL* Geometry update tolerance. If the relative sliding distance betweenthe source and target regions exceeds this tolerance, a geometryupdate will be initiated with large displacement. (Default = 0.25 *characteristic length; REAL>0.0)

FRICMOD Tangential stiffness selection.

0 - The tangential stiffness if fixed throughout the subcase.

1 - The tangential stiffness is adaptively modlfied at every iteration asa function of contact pressure. (Default) The tangential stiffness isthen computed as:

(FRICi * contact pressure) / SCRIT

where FRICi is the coefficient of friction defined on the BCTSET entry,and SCRIT is the critical slip parameter.

SCRIT* Defines the critical slip when FRICMOD=1, where the critical slip =SCRIT * characteristic length for each pair. (Default=0.005; REAL)

A negative SCRIT value is treated as an absolute value and is notscaled by the characteristic length.

DISCAL Displacement scaling option.

0 – No scaling will be done.

1 – Scaling will be done if required during every iteration. A checkwill be performed after every displacement increment to see if theincremental displacements would cause penetration between thesource and target regions. If the penetrations exceed DISTOL, theentire incremental displacements will be scaled back to limit thepenetrations in the model. (Default)

DISTOL Tolerance for displacement scaling feature. (Default = 1.0*characteristic length)

KSTAB Stiffness stabilization for contact.

0 – Stiffness stabilization is off. (Default)

1 – The stiffness matrix is stabilized when it is singular due to inactivecontact constraints. The stabilization adds a factor (1.0) to thediagonal terms of the stiffness matrix. KSTAB=1 is only supportedwith the sparse solver, and will disable any open contact stiffnessspecified through the OPNSTF parameter.





Name Description

AUTOSCAL* When PENN is not defined explicitly, scales the automaticallycalculated normal penalty factor PENN either up or down. AUTOSCALcan be used to scale the stiffness of specific contact pairs ifconvergence issues occur (Real>0.0; Default=1.0). See Remark 2.

TANSCL* When PENT is not defined explicitly, scales the automaticallycalculated tangential penalty factor PENT either up or down.TANSCL can be used to scale the stiffness of specific contact pairs ifconvergence issues occur (Real>0.0; Default=1.0). See Remark 2.

FRICDLY * Option to delay contact friction to help alleviate convergence problems.

0 – Friction is not delayed. (Default)

1 – Friction is delayed. It is not included in the solution until thesecond contact iteration.

Table 5-15. Secondary parameters supported by SOLs 101, 103, 111, and 112:

The following parameters are available for special cases.

Name Description

PENN* Penalty factor for normal direction. PENN and PENT are automaticallycalculated by default. See Remark 2. When PENT is defined butPENN is undefined, PENN = 10 * PENT.

PENT* Penalty factor for transverse direction. PENN and PENT areautomatically calculated by default. See Remark 2. When PENN isdefined but PENT is undefined, PENT = PENN / 10.

PENTYP* Changes how contact element stiffness is calculated (Default=1). SeeRemark 2.

1- PENN and PENT are entered as units of 1/Length.

2 - PENN and PENT are entered as units of Force/(Length x Area).

AUTOSCAL* Scales the automatically calculated penalty factors PENN and PENTeither up or down. AUTOSCAL can be used to scale the stiffnessof specific contact pairs if convergence issues occur (0<Real;Default=1.0). See Remark 2.

RESET Flag to indicate if the contact status for a specific subcase is to startfrom the final status of the previous subcase

0 - Starts from previous subcase. (Default)

1 - Starts from initial state.




Table 5-15. Secondary parameters supported by SOLs 101, 103, 111, and 112:


Name Description



2 - Refinement occurs (default).

INTORD Determines the number of contact evaluation points for a singleelement edge or face on the source region. The number of contactevaluation points is dependent on the value of INTORD, and on thetype of element face. See the table in Remark 4 for specific values.

1 – The reduced number of contact evaluation points is used.

2 – Use an increased number of contact evaluation points (default).

3 – Use a high number of contact evaluation points.

CSTRAT Prevents all of the contact elements from becoming inactive. SeeRemark 5.

0 - All contact elements can become inactive (Default).

1 - The software will reduce the likelihood of all of the contact elementsbecoming inactive.

PREVIEW Requests the export of a bulk data representation of the elementedges and faces where contact elements are created. See Remark 6.

0 - The bulk data export does not occur (Default).

1 - The bulk data export occurs.

Table 5-16. Secondary parameters supported by SOL 401:


Name Description

PENN* Penalty factor for normal direction. PENN and PENT are automaticallycalculated by default. See Remark 2. When PENT is defined butPENN is undefined, PENN = 10 * PENT.

PENT* Penalty factor for transverse direction. PENN and PENT areautomatically calculated by default. See Remark 2. When PENN isdefined but PENT is undefined, PENT = PENN / 1000.




Table 5-16. Secondary parameters supported by SOL 401:


Name Description

PENTYP* Changes how contact element stiffness is calculated (Default=1). SeeRemark 2.

1- PENN and PENT are entered as units of 1/Length.

2 - PENN and PENT are entered as units of Force/(Length x Area).



2 - Refinement occurs (default).

INTORD Determines the number of contact evaluation points for a singleelement edge or face on the source region. The number of contactevaluation points is dependent on the value of INTORD, and on thetype of element face. See the table in Remark 4 for specific values.

1 – The reduced number of contact evaluation points is used.

2 – Use an increased number of contact evaluation points (default).

3 – Use a high number of contact evaluation points.

* Can be defined on local BCTPARM entries. The BCTPARM bulk entries associated toindividual BCTSET bulk entries, which are then combined with a BCTADD bulk entry,define local parameters. A local parameter definition overrides a global definition.

See “Contact Control Parameters – BCTPARM” in the NX Nastran User’s Guide formore information on the BCTPARM options.

REMARKS:1. In SOLs 101, 103, 111, and 112, all of the parameters are supported for

surface-to-surface contact definitions. For edge-to-edge contact definitions, theparameters CTOL, MAXF, MAXS, NCHG, INIPENE, PENN, PENT, PENTYP,RESET, CSTRAT, PREVIEW, and AUTOSCAL are supported.

2. The penalty factors PENN and PENT are automatically calculated by default. Theautomatic calculation is turned off if either PENN or PENT are defined.

When PENTYP=1 (default) is defined, PENN and PENT have units of 1/(Length),and the contact element stiffness is calculated by K = e*E*dA where e representsPENN or PENT, E is the modulus value, and dA is area. A physical interpretationis that it is equivalent to the axial stiffness of a rod with area dA, modulus E, andlength 1/e.




When PENTYP=2 is defined, PENN and PENT become a spring rate per areaForce/(Length x Area), and the contact element stiffness is calculated as K=e*dA.The spring rate input is a more explicit way of entering contact stiffness since it isnot dependent on the modulus value.

The penalty factors influence the rate of convergence, and to a lesser extent, theaccuracy of the contact solution. The automatic penalty factor calculation workswell for most instances, but manual adjustments may be necessary, particularly ifa contact problem fails to converge. See “Tips for Setting PENN and PENT” in theNX Nastran User's Guide for tips on adjusting penalty factors.

3. In SOLs 101, 103, 111, and 112, if NCHG is a real number and is < 1.0, thesoftware treats it as a fraction of the number of active contact elements in eachouter loop of the contact algorithm. The number of active contact elements isevaluated at each outer loop iteration.

If NCHG is an integer ≥ 1, the value defines the allowable number of contactchanges.

If NCHG = 0, no contact status changes can exist.

Consider defining a lower NCHG value than the default when a large number ofpairs are defined in a “stack up” type of configuration where the cumulative effectof a small contact element status change within some of the pairs will impact thecontact element status of the other pairs.

4. A higher number of contact evaluation points can be used to increase the accuracyof a contact solution. Inaccuracies sometimes appear in the form of nonuniformcontact pressure and stress results. There may be a penalty associated withusing more evaluation points since the time for a contact problem to convergemay be longer. The table below shows how the number of contact evaluationpoints is dependent on the element type, and how it can be adjusted using theINTORD option. The “Face Type” column applies to shell elements, and to thesolid element with the associated face type.

Number of Contact Evaluation PointsFace Type INTORD=1 INTORD=2 INTORD=3Linear Triangle 1 3 7Parabolic Triangle 3 7 12Linear Quad 1 4 9Parabolic Quad 4 9 16

5. In SOLs 101, 103, 111, and 112, under certain conditions, all of the contactelements could become inactive which may lead to singularities. Setting theparameter CSTRAT=1 will reduce the likelihood of all contact elements becominginactive.

6. In SOLs 101, 103, 111, and 112, setting the PREVIEW parameter to “1” requests abulk data representation of the element edges and faces where contact elementsare created. The software will write a bulk data file containing dummy shellelement entries for face locations, and dummy PLOTEL entries for edge locations.Dummy GRID, property and material entries are also written. You can import the




file into a preprocessor to display both source and target contact locations. Thepreview file has the naming convention

<input_file_name>_cnt_preview_<subcaseid>_<contactsetid>.dat

7. In SOLs 101, 103, 111, and 112, the following applies to the initial contactcondition* when INIPENE= 2 or 3:

* The initial contact condition is the contact status before the solution iterates on thecontact condition. This is the contact status before the solution has applied loads.

• If shell element contact regions exist and SHLTHK=0 (default) on theBCTPARM entry, the shell element thickness is applied before the softwareevaluates any gaps or penetrations as a result of the INIPENE setting. Forexample, when INIPENE=2, penetrations are reset to a new initial conditionin which there is no interference. This includes the penetrations as a resultof the shell thickness. When INIPENE=3, since penetrations and gaps arereset to a new initial condition, the shell thickness is not considered by thecontact condition.

• If shell element contact regions exist, and a shell element offset is definedwith the ZOFF field on the element entry, and ZOFFSET=0 (default) on theBCTPARM entry, the shell element offset is added after the software removesany gaps or penetrations as a result of the INIPENE setting.

8. If a region offset is defined with the OFFSET parameter on the BCRPARA entry,the region offset is added after the software removes any gaps or penetrations asa result of the INIPENE setting.




BCRPARA

Contact Face and Edge Region Parameters

Defines parameters for a contact face or edge region.FORMAT:

1 2 3 4 5 6 7 8 9 10

BCRPARA CRID SURF OFFSET TYPE MGP

EXAMPLE:

BCRPARA 1 TOP 0.02

FIELDS:

Field Contents

CRID Contact region ID. (Integer > 0)

SURF Indicates the contact side of shell elements. See Remark 1 andSOL 601 and 701 Remarks 1 and 2. (Character=“TOP” or “BOT”;Default=“TOP”)

OFFSET Offset distance for an edge or surface contact region.For SOLs 101, 103, 111, 112, and 401: Real, Default = 0.0For SOLs 601 and 701: Real >= 0.0, Default = OFFSET value inBCTPARA entry. See SOL 601 and 701 Remark 3.

TYPE Indicates whether a 3D contact region is a rigid (target) surface or isa shell coating on solid elements. See Remarks 4 to 8 in the SOL601 and 701 remarks. (Character=“FLEX”, “RIGID” or “COATING”.Default=“FLEX”). This is only supported by SOLs 601 and 701.

MGP Master grid point for a target contact region with TYPE=RIGID orwhen the rigid-target algorithm is used. The master grid point may beused to control the motion of a rigid surface. (Integer ≥ 0,; Default=0)This is only supported by SOLs 601 and 701.

REMARKS:1. The BCRPARA bulk entry is not required. When it is not present, the default

values are used.

2. SURF is used to define the contact side of shell element regions. When SURFis "TOP", the contact side is consistent with the shell element normal and when"BOT" the opposite. In a SOL 101 (including consecutive solutions 103, 111and 112), SURF must be defined so that source and target contact sides eitherface one another to represent a separation condition, or oppose one anotherto represent an interference condition.




REMARKSRELATED TOSOL 601 AND

701:1. For a 3D contact region, SURF is applicable only for a single-sided contact region

defined on shell elements (i.e., using BSURF or BCPROP) and is used as atarget region. For a contact region defined on 3D solid element faces (i.e., usingBSURFS), the contact side is automatically determined by the program. For acontact region used as a source region (contactor), it does not matter which isthe contact side.

2. For a 2D contact region, SURF is only applicable to a rigid target region definedby grid points that are not attached to any elements. For a 2D contact regionwith underlying 2D elements, the contact side is automatically determined bythe program.

3. OFFSET is only applicable when the rigid target algorithm is not selected, (i.e.,TYPE or XTYPE=0 or 1 in the BCTPARA entry).

4. TYPE=“RIGID” is ignored if the contact region is used as a source region.

5. If the rigid target algorithm is selected (i.e., TYPE=2 (SOL 601) or XTYPE= 3 (SOL701) in BCTPARA command), the target region must be attached to shell elementsonly (i.e., using BSURF or BCPROP) and it is automatically set as rigid.

6. TYPE and MGP are interpreted as follows:

• 2D target regions using grids only (not attached to underlying elements) arealways rigid. MGP>0 can be specified without TYPE=RIGID.

• 2D target regions with underlying elements will behave as rigid only whenboth TYPE=RIGID and MGP>0 are specified. Otherwise, the target region isflexible and MGP is ignored.

• 3D target regions that are attached to solid elements will behave as rigid onlywhen both TYPE=RIGID and MGP>0 are specified. Otherwise, the targetregion is flexible and MGP is ignored.

• 3D target regions that are attached to shell elements (i.e., using BSURF orBCPROP), only TYPE=RIGID is required for the region to behave as rigid.MGP is ignored when TYPE=FLEX.

7. TYPE=“COATING” should only be specified for a contact region defined on shellelements (i.e., using BSURF or BCPROP), coated on solid elements. The contactregion will be transferred onto the solid element faces and the shell elementswill be deleted. If there are no underlying solid elements, an error message willbe issued.

8. A contact region is specified as a target or source region in the BCTSET entry.




9. When TYPE=COATING, the shell elements should match the solid element faces,i.e. element edges should match, linear shell on linear solid face, and parabolicshell on parabolic solid face.

User defined materialsSolution 401 now supports externally computed, user defined material models. You can now define amaterial model by developing and compiling an external routine. The external routine can optionallyinclude multiple material models.

Source code examples are included with the NX Nastran installation for you to begin your ownexternal material development. A Ready-to-run routine and test cases along with NX Nastran inputfiles are also included to demonstrate the input file requirements and the general workflow.

You can develop an external material routine using FORTRAN or C, and compile for Windows or Linuxoperating systems. You must use the NX Nastran ILP-64 executable with an external material routine.

NX Nastran Inputs

The new MUMAT bulk entry is available to define the material data in the NX Nastran input file. NXNastran passes this data to the external routine. The MUMAT entry in your input file is the triggerNX Nastran uses to call the external routine.

The elements referencing the MUMAT entry material ID will use an associated material law defined inthe user defined material routine NXUMAT. See NXUMAT interface for the NXUMAT API description.The elements referencing the MUMAT entry must also reference MAT1, MAT9 or MAT11 entries. NXNastran uses the MATi properties to compute the initial elastic stiffness. Temperature dependentmaterials are also supported and are used by NX Nastran when computing the initial elastic stiffness.The initial elastic stiffness computed by NX Nastran and the data defined on the MATi, MATTI, andTABLEMi entries are all passed from NX Nastran to the external routine.

All of the data defined on the MUMAT bulk entry is also passed to the NXUMAT routine. You caninclude a variety data types on the MUMAT entry. For example, real, integer, tables and table oftables can all be included.

The following data is supported on the MUMAT entry:

• MODNAME1 and MODNAME2 fields - Optional character fields.

• MATNAME field - Can be used to request a specific material model.

• NUMSTAT field - Defines the total number of state variables, if they exist.

The following tabular data is supported on the MUMAT entry:

Note: When you reference TABLES1, TABLEM1, TABLEST entries on the MUMAT entry, NX Nastrandoes no interpolation or extrapolation of the data before passing it to the external routine.

• TABLES1 - This is a collection of real data pairs. You reference the ID of TABLES1 entriesdefined in your NX Nastran input file.

• TABLEM1 - This is a collection of real data pairs. You reference the ID of TABLEM1 entriesdefined in your NX Nastran input file.




• TABLEST - This is a collection real data values versus table ID’s. The table ID's reference othertables with a collection of real data pairs. You reference the ID of TABLEST entries defined inyour NX Nastran input file.

NX Nastran also optionally stores, retrieves, and outputs state variable data computed by theexternal routine. For example, stress, creep strain and plastic strain at each solution incrementcan be stored as state variables. You define the number of state variables in the NUMSTAT fieldon the MUMAT entry, and NX Nastran will initialize the appropriate storage. The flow of statevariable data is as follows:

• Your external routine provides NX Nastran with updated state variables at the end of a time step.

• NX Nastran stores the variables in the database.

• NX Nastran provides the data back to the external routine at the beginning of the consecutivetime step.

You can request NX Nastran to output the state variables using the new STATVAR case controlcommand. Regardless of what the data is originally, for example, vector or tensor components, NXNastran outputs all of the state variable data as scalar values. The GRID/GAUSS output optionis also available on the STATVAR command.

You can pass parameters defined in the NX Nastran input file to the external routine. This includesparameters defined with the PARAM case control, the PARAM bulk entry, and the PLASTIC, CREEP,and the MATNL parameter settings defined on the NLCNTL bulk entry. You can use these settings inyour external routine, for example, to turn on/off specific material computations in a subcase.

MUMAT entry format

1 2 3 4 5 6 7 8 9 10

MUMAT MID MODNAME1 MODNAME2 NUMSTAT MATNAME SETID

REAL REAL1 REAL2 REAL3 ...

INTEGER INTEGER1 INTEGER2 INTEGER3 ...

TABLES1 TIDS1 TIDS2 TIDS3 ...

TABLEST TIDST1 TIDST2 TIDST3 ...

TABLEM1 TIDM1 TIDM2 TIDM3 ...

MUMAT Example:

1 2 3 4 5 6 7 8 9 10

MUMAT 21 MODELA MODELB 5 TESTMAT1 6 ++ INTEGER 98 187 574 ... ++ REAL 1.111 2.222 R3 ... ++ TABLES1 101 102 103 104 105 106 107 ++ TABLES1 111 112 113 114 115 116 117 ++ 121 122 123 124 125 126 127 ++ TABLES1 131 132 133 134 135 136 137 ++ TABLEST 303 202 203 204 205 206 207 ++ 211 212 213 214 215 +




1 2 3 4 5 6 7 8 9 10+ TABLEM1 301 TIDST2 TIDST3 ... ++ TABLES1 148 149 +

MUMAT fields:

Field Contents

MID Identification number of a MAT1, MAT9, or MAT11 entry. (Integer > 0)

MODNAME1 Material model name. (Character)

MODNAME2 Material model name. (Character)

NUMSTAT Number of state variables. (Integer, default=0)

MATNAME Material name. (Character)

SETID Identification number of a SET1 entry which lists the state variables for NXNastran to output. SETID=-1 requests that all state variables be output.(Integer, default=0)

REALi Material constants that are type REAL. (Real) Double precision is allowed. forexample, 1.2345D6, but NX Nastran will convert them to REAL before storing.

INTEGERi Material constants that are type INTEGER. (Integer)

TIDSi Identification number of a TABLES1 entry. (Integer>0)

TIDSTi Identification number of a TABLEST entry. (Integer>0)

TIDMi Identification number of a TABLEM1 entry. (Integer>0)

MUMAT remarks:

1. If a REAL, INTEGER, TABLES1, TABLEST, or TABLEM1 row is repeated, the data type in field 2( REAL, INTEGER, TABLES1, TABLEST, TABLEM1) is optional in the consecutive row as long asthe previous row is fully defined. That is, the previous row has data in fields 3 through 9.

2. You can optionally use the MODNAME1, MODNAME2, and MATNAME character fields howeveryou would like to apply them in your external subroutine. For example, you may have multiplematerial models in the same routine, and these fields could be used to branch to a specific model.

NXUMAT interface

The subroutine NXUMAT directs NX Nastran to a specific material model. A shared library (DLL/SOfile) is built from this routine and used by NX Nastran to model the material behavior. The buildingprocess of the shared library is described in Compiling instructions.

The arguments of NXUMAT are detailed below. NX Nastran expects that the real, integer andcharacter values passed from the argument list are or precision REAL*8, INTEGER*8 andCHARACTER (LEN=8).

SUBROUTINE NXUMAT(IOPER, MODNAME1, MODNAME2, MATID, HOOK, TANSTIFF,MATIR, MATIN, NMATI, MUDATAR, MUDATAI, NMUDATA ,




DFGRDT0, DFGRDT1, EPSTOTT1, EPSMT1, EPSTHT1, EPSDELM,DELTAT, TIMET1, TEMPT0, TEMPT1, NB, INTVALS,REALVALS, XYZT1, ROT, NXPARAM, STATEVAR, NSVAR,SIGMA, EPSPL, EPSCR, DTCRPRAT, VOID1, VOID2, VOID3, IRET)

FUNCTION : USER MATERIAL DEFINITIONTHIS ROUTINE IS DIVIDED IN THREE STEPS (IOPER)

IF (IOPER.EQ.0) THENNXUMAT DLL VERSION NUMBER

ELSEIF (IOPER.EQ.1) THENINITIALIZATION OF STATEVAR

ELSECOMPUTATION OF MATERIAL LAW

ENDIFEND

Each of the arguments of the NXUMAT routine is described below.

IOPER (Input)

IOPER defines the operational step for which NXUMAT has been called for.

IOPER = 0: this is used to facilitate versioning for the NXUMAT library. This number is read fromthe argument STATEVAR(1). This float is printed to the F06 file as a user information message23209 along with the value In STATEVAR(1).

Example

*** USER INFORMATION MESSAGE 23209 (IFPDRV)VERSION 1.00 OF NXUMAT DLL LOADED.

IOPER=1: this is used to initialize state variables. This step can be used to assign initial values tothe STAEVAR array, which will be stored by NX Nastran and returned in the computational step.

IOPER>1: this is considered the computational step.

MODNAME1 (Input)

MODNAME1 contains the eight-character name from the MUMAT entry.

MODNAME2 (Input)

MODNAME2 contains the eight-character name from the MUMAT entry.

MATID (Input)

MATID is the material ID given in the MUMAT entry.

HOOK(NB,NB) (Input)

HOOK is an NBxNB-size matrix containing the hook’s matrix. This is pre-computed byNX Nastran based on the MAT1/MAT9/MAT11 entries associated with the MUMAT entry.

TANSTIFF(NB,NB) (Input/Output)




TANSTIFF contains the tangent stiffness matrix computed at the previous time step when enteringNXUMAT and should be updated with the tangent stiffness matrix for the current time stepupon convergence.

MATIR(NMATI) (Input)

MATIR contains the real data from the associated MAT1/MAT9/MAT11 entries. Its format isexplained in MATIN/MATIR array format.

MATIN(NMATI) (Input)

MATIN contains the integer data from the associated MAT1/MAT9/MAT11 entries. Its format isexplained in MATIN/MATIR array format.

NMATI (Input)

NMATI is the size of the MATIR/MATIN array.

MUDATAR (NMUDATA) (Input)

MUDATAR contains the real data from the MUMAT entries. Its format is explained inMUDATAI/MUDATAR array format.

MUDATAI (NMUDATA) (Input)

MUDATAI contains the real data from the MUMAT entry. Its format is explained inMUDATAI/MUDATAR array format.

NMUDATA (Input)

NMUDATA is the size of the MUDATAR/MUDATAI array.

DFGRDT0(3,3) (Input)

Deformation gradient at the previous time step. This is not defined in NX Nastran 11.

DFGRDT1(3,3) (Input)

Deformation gradient at the previous time step. This is not defined in NX Nastran 11.

EPSTOTT1(NB) (Input)

Total strain tensor (including mechanical and thermal strain).

EPSMT1(NB) (Input)

Mechanical strain.

EPSTHT1(NB) (Input)

Thermal strain.

EPSDELM(NB) (Input)

Mechanical strain increment.

DELTAT (Input)




Time step.

TIMET1 (Input)

Current time.

TEMPT0 (Input)

Temperature at the previous time step.

TEMPT1 (Input)

Temperature at the current time step.

NB (Input)

Number of tensor components.

INTVALS(*) (Input)

The INTVALS array contains various integer data, including the following:

INTVALS(1) contains the element ID.

INTVALS(2) contains the gauss ID.

INTVALS(3) contains the current time step number.

INTVALS(4) contains the iteration number for the current time step.

INTVALS(5) contains the subcase ID.

REALVALS(*) (Input)

The REALVALS array contains various real data, including the following:

REALVALS(1) contains the element thickness for shell elements.

XYZT1(3) (Input)

XYZT1 contains the updated coordinates of the current gauss point.

ROT(3,3) (Input)

ROT contains the rotational matrix between the structural and material coordinate systems.

NXPARAM(*) (Input)

NXPARAM contains the list of PARAM entry values that are in the input testcase. You can passparameters defined in the NX Nastran input file to the external routine. This includes parametersdefined with the PARAM case control, the PARAM bulk entry, and the PLASTIC, CREEP, andMATNL parameter settings defined on the NLCNTL bulk entry. You can use these settings in yourexternal routine, for example, to turn on/off specific material computations in a subcase. Refer tothe included utility routine PARAMQRY to understand how to use this functionality.

STATEVAR(NSVAR) (Input/Output)




STATEVAR contains the state variables that you specified. It contains the previous time stepstate variables as input and must be updated with current state variables upon convergence.

NSVAR (Input)

NSVAR is the number of state variables.

SIGMA(NB) (Input/Output)

SIGMA contains the stress tensor from the previous time step and must be updated with thecurrent time step value upon convergence.

EPSPL(NB) (Input/Output)

EPSPL contains the plastic strain tensor from the previous time step and must be updated withcurrent time step value upon convergence. This strain tensor is stored inside NX Nastran andis output when requested.

EPSCR(NB) (Input/Output)

EPSCR contains the creep strain tensor from the previous time step and must be updated withcurrent time step value upon convergence. This strain tensor is stored inside NX Nastran andis output when requested.

DTCRPRAT (Output)

DTCRPRAT is the creep time step ratio which can be used as the time stepping control for creep.

VOID1, VOID2, VOID3

These are empty slots for future use.

IRET (Output)

IRET is the return code. Any returned value other than 0 (>0) will stop the solution and issue afatal message with the return code.

The user data specified on the MUMAT entry and corresponding MAT1, MAT9, or MAT11 entry ispassed to the NXUMAT routine via the arrays MUDATAI/MUDATAR and MATIN/MATIR respectively.This section describes the layout of the input data arrays supplied to the NXUMAT subroutine.

Each entry (that is, the MUMAT entry and the MAT* entry) is stored in two arrays each. One array hasthe integer data and the other has the real data. Some cross-referencing between the two arraysmust be done to extract the desired data. The format of these arrays is described in the followingsections. These arrays are declared as INTEGER*8 for the integers and REAL*8 for the real portion.

MATIN/MATIR array format

MAT1,MAT9, and MAT11 data along with corresponding MATT1,MATT9, and MATT11 entries are sentto the NXUMAT routine through two arrays: MATIN and MATIR. Both MATIN and MATIR representthe MAT* entry data in the format laid out in the following table. The integer data of the MAT* andMATT* entries exist in MATIN and the real data exist in the MATIR array.

The first word in the array is the total number of words in the array. The second word is the offset tothe mapping array. The mapping array has information on the location of each table of data. Thethird word identifies the type of the array: 1 corresponds to the MATIN array and 2 corresponds to




the MUDATAI array. The fourth word is the material ID, and the fifth word contains the type of theMAT* entry (1, 9, or 11). Based on the type of MAT* entry for which this array contains data, thenext ‘N’ words from the sixth word contain the bulk entry data (N=11, 20, and 15 for the MAT1,MAT9, and MAT11 entry respectively). After that, in the next word (if any), corresponding MATT*entries are present, including its ID. If no MATT* entries are present, this word is zero. If the MATT*entry is present, after the ID the MATT* entries are laid out next. If MATT* entries are present, thatmeans TABLEM1 data is present. This is laid out next in the array. Each table has a fixed formatas shown in the following table and is ended by a -1. Multiple tables can exist. The mapping arrayis laid out in the end.

Word Description1 Total length of data used in this array (LENGTH).2 Offset to the mapping array (array index).3 The ID code for a MATIN array is always 1.

The ID code is used by the interpolation routines to identify the data structure.4 Material ID used to setup the array.5 MAT table type:

1: The record contains MAT1 data.

9: The record contains MAT9 data.

11: The record contains MAT11 data.6 Number of entries in the record (N):

If the MAT table type is 1, N = 11.

If the MAT table type is 9, N = 20.

If the MAT table type is 11, N = 15.7 through N+6 MAT* constants (real).N+8 MATT* ID (0 if no MATT* entry).N+9 through 2N+8 MATT* entries (integers).N+6 throughLENGTH

TABLEM1 data tables (CODEX/CODEY: 0=Linear, 1=Log):

1. Table identification number (if 0, no table).

2. NUMPAIR: Number of X-Y Pairs.

3. CODEX: Type of interpolation for the x-axis (integer).

4. CODEY: Type of interpolation for the y-axis (integer).

5. EXTRAP: Extrapolation option.

6. X tabular value (real).

7. Y tabular value (real).

- Words 6 through 7 repeated NUMPAIR.




Word Description

(-1) end of TABLEM1 tables.Mapping

1. Table ID.

2. Array index pointing to the table data.

For example, consider a MAT9 entry as show below along with a MATT9 entry and correspondingTABLEM1 entries.

MAT9 1 1.+7 2.5+6 1.+6 0. 0. 0. 1.+7++ 1.+6 0. 0. 0. 3.+7 0. 0. 0.++ 3.75+6 0. 0. 1.75+6 0. 1.75+6 0.1 1.-5++ 1.-5 1.-5 1.-5 1.-5 1.-5 0.

MATT9 1 1 1++ 3 +

+ 1 2++ 2 2 2 2 2

TABLEM1 2 LINEAR LINEAR +

+ 50. 1.-5 200. 1.-5 ENDT


+ 50. 1e+7 200. 7e+6 ENDT


50. 3e+7 200. 1e+7 ENDT

Using the information above, these entries are formatted into the array shown below.

Description MATIN IntegerData MATIR Real Data

1 Length MATIN(1) 104 MATIR(1) 0.000000000000000D+0002 Offset MATIN(2) 99 MATIR(2) 0.000000000000000D+0003 MAT* Identifier MATIN(3) 1 MATIR(3) 0.000000000000000D+0004 MID MATIN(4) 1 MATIR(4) 0.000000000000000D+0005 MAT* type MATIN(5) 9 MATIR(5) 0.000000000000000D+000

6 No. of MAT9 dataEntries MATIN(6) 30 MATIR(6) 0.000000000000000D+000

7 MAT9 data (refer toMATIR) MATIN(7) 0 MATIR(7) 10000000



10 MAT9 data (refer toMATIR) MATIN(10) 0 MATIR(10) 0.000000000000000D+000






















28 MAT9 data (refer toMATIR) MATIN(28) 0 MATIR(28) 0.1

29 MAT9 data (refer toMATIR) MATIN(29) 0 MATIR(29) 1.000000000000000D-005












37 MATT9 ID MATIN(37) 1 MATIR(37) 0.000000000000000D+00038 MATT9 entries MATIN(38) 1 MATIR(38) 0.000000000000000D+00039 MATT9 entries MATIN(39) 0 MATIR(39) 0.000000000000000D+00040 MATT9 entries MATIN(40) 0 MATIR(40) 0.000000000000000D+00041 MATT9 entries MATIN(41) 0 MATIR(41) 0.000000000000000D+00042 MATT9 entries MATIN(42) 0 MATIR(42) 0.000000000000000D+00043 MATT9 entries MATIN(43) 0 MATIR(43) 0.000000000000000D+00044 MATT9 entries MATIN(44) 1 MATIR(44) 0.000000000000000D+00045 MATT9 entries MATIN(45) 0 MATIR(45) 0.000000000000000D+00046 MATT9 entries MATIN(46) 0 MATIR(46) 0.000000000000000D+00047 MATT9 entries MATIN(47) 0 MATIR(47) 0.000000000000000D+00048 MATT9 entries MATIN(48) 0 MATIR(48) 0.000000000000000D+00049 MATT9 entries MATIN(49) 3 MATIR(49) 0.000000000000000D+00050 MATT9 entries MATIN(50) 0 MATIR(50) 0.000000000000000D+00051 MATT9 entries MATIN(51) 0 MATIR(51) 0.000000000000000D+00052 MATT9 entries MATIN(52) 0 MATIR(52) 0.000000000000000D+00053 MATT9 entries MATIN(53) 1 MATIR(53) 0.000000000000000D+00054 MATT9 entries MATIN(54) 0 MATIR(54) 0.000000000000000D+00055 MATT9 entries MATIN(55) 0 MATIR(55) 0.000000000000000D+00056 MATT9 entries MATIN(56) 0 MATIR(56) 0.000000000000000D+00057 MATT9 entries MATIN(57) 0 MATIR(57) 0.000000000000000D+00058 MATT9 entries MATIN(58) 0 MATIR(58) 0.000000000000000D+00059 MATT9 entries MATIN(59) 0 MATIR(59) 0.000000000000000D+00060 MATT9 entries MATIN(60) 2 MATIR(60) 0.000000000000000D+00061 MATT9 entries MATIN(61) 2 MATIR(61) 0.000000000000000D+00062 MATT9 entries MATIN(62) 2 MATIR(62) 0.000000000000000D+00063 MATT9 entries MATIN(63) 2 MATIR(63) 0.000000000000000D+00064 MATT9 entries MATIN(64) 2 MATIR(64) 0.000000000000000D+00065 MATT9 entries MATIN(65) 2 MATIR(65) 0.000000000000000D+00066 MATT9 entries MATIN(66) 0 MATIR(66) 0.000000000000000D+00067 MATT9 entries MATIN(67) 0 MATIR(67) 0.000000000000000D+00068 MATT9 entries MATIN(68) 0 MATIR(68) 0.000000000000000D+00069 TABLEM1 ID MATIN(69) 1 MATIR(69) 0.000000000000000D+00070 No. of XY data MATIN(70) 2 MATIR(70) 0.000000000000000D+00071 CODEX MATIN(71) 0 MATIR(71) 0.000000000000000D+00072 CODEY MATIN(72) 0 MATIR(72) 0.000000000000000D+000

73 EXTRAPOLATIONoption MATIN(73) 0 MATIR(73) 0.000000000000000D+000





74 X(1) MATIN(74) 0 MATIR(74) 5075 Y(1) MATIN(75) 0 MATIR(75) 1000000076 X(2) MATIN(76) 0 MATIR(76) 20077 Y(2) MATIN(77) 0 MATIR(77) 700000078 TABLEM1 End MATIN(78) -1 MATIR(78) 0.000000000000000D+00079 TABLEM1 ID MATIN(79) 3 MATIR(79) 0.000000000000000D+00080 No. of XY data MATIN(80) 2 MATIR(80) 0.000000000000000D+00081 CODEX MATIN(81) 0 MATIR(81) 0.000000000000000D+00082 CODEY MATIN(82) 0 MATIR(82) 0.000000000000000D+000


84 X(1) MATIN(84) 0 MATIR(84) 5085 Y(1) MATIN(85) 0 MATIR(85) 3000000086 X(2) MATIN(86) 0 MATIR(86) 20087 Y(2) MATIN(87) 0 MATIR(87) 1000000088 TABLEM1 End MATIN(88) -1 MATIR(88) 0.000000000000000D+00089 TABLEM1 ID MATIN(89) 2 MATIR(89) 0.000000000000000D+00090 No. of XY data MATIN(90) 2 MATIR(90) 0.000000000000000D+00091 CODEX MATIN(91) 0 MATIR(91) 0.000000000000000D+00092 CODEY MATIN(92) 0 MATIR(92) 0.000000000000000D+000


94 X(1) MATIN(94) 0 MATIR(94) 5095 Y(1) MATIN(95) 0 MATIR(95) 1.000000000000000D-00596 X(2) MATIN(96) 0 MATIR(96) 20097 Y(2) MATIN(97) 0 MATIR(97) 1.000000000000000D-00598 TABLEM1 End MATIN(98) -1 MATIR(98) 0.000000000000000D+00099 Mapping array starts.

Table ID, offset givenbelow

MATIN(99) 1 MATIR(99) 0.000000000000000D+000

100 Index to Table ID above MATIN(100) 69 MATIR(100) 0.000000000000000D+000101 Table ID MATIN(101) 3 MATIR(101) 0.000000000000000D+000102 Index to Table ID above MATIN(102) 79 MATIR(102) 0.000000000000000D+000103 Table ID MATIN(103) 2 MATIR(103) 0.000000000000000D+000104 Index to Table ID above MATIN(104) 89 MATIR(104) 0.000000000000000D+000

MUDATAI/MUDATAR array format

The data defined on the MUMAT bulk entry is passed to the NXUMAT routine via the MUDATAI andMUDATAR arrays. Both MUDATAI and MUDATAR represent the MUMAT entry data in the format laidout in the following table. The integer data of MUMAT exist in MUDATAI and the real data exist inthe MUDATAR array.




The first word in the array is the total number words in the array. The second word is the offset tothe mapping array. The mapping array has information of the location of each table of data. Thethird word identifies the type of array: 1 corresponds to the MATIN array and 2 corresponds to theMUDATAI array. The next six words are the data present on the first line of the MUMAT entry. Afterthis, the next word contains a code that identifies the type of data that is to follow (1 for real, 2 forinteger, 3 for TABLES1, 4 for TABLEST, 5 for TABLEM1, and 6 for a mapping array). After the code,the next word is the size of the array for this ‘code data’ followed by the data. Note that multiple typesof data can exist, so expect multiple codes followed by their corresponding data.

After this, the table data is laid out for each TABLES1, TABLEST, and TABLEM1 on the MUMATentry. The format is shown in the following table.

Word Description1 Total length of data used in this array (LENGTH).2 Offset to the mapping array (array index).3 The ID code for a MUDATAI array is 2 for MUMAT.

The ID code is used by the interpolation routines to identify the data structure.4-10 First line of the MUMAT Bulk Data Entry.11 Code descriptor :

0: End of Data, or no data if the first word is 0.

1: REAL Data.

2: INTEGER Data.

3: TABLES1 Data.

4: TABLEST Data.

5: TABLEM1 Data.

6: Mapping.Code = 1 REAL data

Size of array

2-n) Real dataCode = 2 INTEGER data

Size of array

2-n) Integer dataCode = 3 TABLES1 data

Size of array

2-n) Table IDsCode = 4 TABLEST data

Size of array

2-n) Table IDs




Word DescriptionCode = 5 TABLEM1 data

Size of array

2-n) Table IDsCode = 6 Mapping

1. Size of the mapping array.

2. Table ID.

3. Table Type (code 3, 4, 5)

4. Array Index pointing to the table dataTABLES1 data 1. Table identification number (if 0, no table) (integer).

2. NUMPAIR: Number of X-Y pairs.



Words 3 and 4 repeated NUMPAIR.TABLEST data 1. Table identification number (if 0, no table) (integer).


3. EXTRAP: Extrapolation option (0=no extrapolation, 1=extrapolation).


5. TID: Table ID (integer).

Words 4 and 5 repeated NUMPAIR.TABLEM1 data (CODEX/CODEY: 0=Linear, 1=Log)

1. Table identification number (if 0, no table) (integer).


3. CODEX: Type of interpolation for the X-axis (integer).

4. CODEY: Type of interpolation for the Y-axis (integer).

5. EXTRAP: Extrapolation option (0=no extrapolation, 1=extrapolation).



Words 6 and 7 repeated NUMPAIR.




For example, consider the MUMAT entry below along with a TABLES1 entry.

MUMAT 1 NLPLAST

$+ INTEGER 1 1 2 0

$ YF HR METHOD NLTYPE

$ 2 3 4 5 6 7 8 9 10

+ REAL 0.0 9.+2

$ H/EP LIMIT1 E NU RHO A TREF

+ TABLES1 80

TABLES1 80 +

+ 0.0 0.0 7.5-4 9.+2 17.5-4 1.5+327.5-42.0+3 +

+ ENDT

Using the information above, these entries are formatted into the array shown below.


1 Length of thearray MUDATAI(1) 38 MUDATAR(1) 0.000000000000000D+000

2 Offset MUDATAI(2) 24 MUDATAR(2) 0.000000000000000D+000

3 MUMATidentifier MUDATAI(3) 2 MUDATAR(3) 0.000000000000000D+000

4 MUMAT data MUDATAI(4) 1 MUDATAR(4) 0.000000000000000D+0005 MUMAT data MUDATAI(5) 2.31E+18 MUDATAR(5) 0.000000000000000D+0006 MUMAT data MUDATAI(6) 2.31E+18 MUDATAR(6) 0.000000000000000D+0007 MUMAT data MUDATAI(7) 0 MUDATAR(7) 0.000000000000000D+0008 MUMAT data MUDATAI(8) 0 MUDATAR(8) 0.000000000000000D+0009 MUMAT data MUDATAI(9) 7 MUDATAR(9) 0.000000000000000D+00010 MUMAT data MUDATAI(10) 2.31E+18 MUDATAR(10) 0.000000000000000D+00011 Code

descriptor

1 = Real data

MUDATAI(11) 1 MUDATAR(11) 0.000000000000000D+000

12 Size of realdata MUDATAI(12) 2 MUDATAR(12) 0.000000000000000D+000

13Value(1) inMUDATARarray


14Value(2) inMUDATARarray

MUDATAI(14) 0 MUDATAR(14) 900

15 Codedescriptor

2 = Integer data


16 Size of Integerdata MUDATAI(16) 4 MUDATAR(16) 0.000000000000000D+000





17 Value(1) MUDATAI(17) 1 MUDATAR(17) 0.000000000000000D+00018 Value(2) MUDATAI(18) 1 MUDATAR(18) 0.000000000000000D+00019 Value(3) MUDATAI(19) 2 MUDATAR(19) 0.000000000000000D+00020 Value(4) MUDATAI(20) 0 MUDATAR(20) 0.000000000000000D+00021 Code

descriptor

3 = Tables1data


22 Number ofTables1

Table IDs


23 Tables1 ID MUDATAI(23) 80 MUDATAR(23) 0.000000000000000D+00024 Code

descriptor

6 = Mappingdata


25 Size ofMapping data MUDATAI(25) 3 MUDATAR(25) 0.000000000000000D+000

26 Table ID MUDATAI(26) 80 MUDATAR(26) 0.000000000000000D+00027 Table Type

3 = Tables1


28 Index toTables1 data MUDATAI(28) 29 MUDATAR(28) 0.000000000000000D+000

29 Tables1 ID MUDATAI(29) 80 MUDATAR(29) 0.000000000000000D+00030 No. of XY pairs MUDATAI(30) 4 MUDATAR(30) 0.000000000000000D+00031 X(1) MUDATAI(31) 0 MUDATAR(31) 0.000000000000000D+00032 Y(1) MUDATAI(32) 0 MUDATAR(32) 0.000000000000000D+00033 X(2) MUDATAI(33) 0 MUDATAR(33) 7.500000000000000D-00434 Y(2) MUDATAI(34) 0 MUDATAR(34) 90035 X(3) MUDATAI(35) 0 MUDATAR(35) 1.750000000000000D-00336 Y(3) MUDATAI(36) 0 MUDATAR(36) 150037 X(4) MUDATAI(37) 0 MUDATAR(37) 2.750000000000000D-00338 Y(4) MUDATAI(38) 0 MUDATAR(38) 2000

Source code examples

Source code examples are included with the NX Nastran installation at the following locations.

• Source code written in C can be found at:installation_location\nxn11\nxumat\democ\

• Source code written in FORTRAN can be found at:installation_location\nxn11\nxumat\demof\




Compiling instructions

The source code examples are located with the installation at the following locations.

• The FORTRAN source code and compile procedures are located at:installation_location\nxn11\nxumat\demof

• The C source code and compile procedures are located at:installation_location\nxn11\nxumat\democ

The example source code has been tested with the Intel Compiler 13. The resulting .dll for Windowsand the resulting .so for Linux, both generated from this compiler version, have been tested andverified to work with NX Nastran 11. You can use any compiler as long as you adhere to the standardNXUMAT description in the provided source code, and the compiled .dll or .so file uses one of thefollowing handles as entry points:NXUMAT, NXUMAT_, nxumat or nxumat_.

Template make files are provided in the democ and demof folders for both Windows and Linuxoperating systems.

If you run “nmake libumat.dll” in the demof or democ folders on a Windows machine, a Windowsshared library (libnxumat.dll) will be produced from the FORTRAN or C code, respectively.

If you run “make libumat.so” in the demof or democ folders on a Linux machine, a Linux shared library(libnxumat.so) will be produced from the FORTRAN or C code, respectively.

This assumes that you have an Intel Fortran or C compiler, and the nmake or make utility on Windowsor Linux, respectively. You will need to point to proper compilers and linkers in the makefiles tosuccessfully compile.

Ready-to-run routine and test cases

Compiled example routines and NX Nastran input files are included with the NX Nastran installationto demonstrate the input file requirements and the general workflow.

• On Windows:Compiled Fortran code: installation_location\nxn11\em64tntl\libnxumat_demofCompiled C code: installation_location\nxn11\em64tntl\libnxumat_democ.dll

• On Linux:Compiled Fortran code: installation_location\nxn11\x86_64linuxl\libnxumat_demof.soCompiled C code: installation_location\nxn11\x86_64linuxl\libnxumat_democ.so

Before using the compiled examples, you will need to follow the instructions in Material library pathto point NX Nastran to a compiled example library. You can point NX Nastran to either the Fortranor the C compiled example.

Nine material models are included in the compiled example. You can select a specific model in yourNX Nastran input file with the MODNAME1 field on the MUMAT bulk entry.

The following table summarizes the nine material models, the MODNAME1 input definition youuse to select a specific material model, and a ready-to-run NX Nastran input file nxumatex*.dat foreach material model.

You can find the ready-to-run input files at:installation_location\nxn11\nxumat\demodat\




MODNAME1 Input File DescriptionEISO nxumatex1.dat Isotropic, temperature independentEORTHO nxumatex2.dat Orthotropic, temperature independentEANISO nxumatex3.dat Anisotropic, temperature independentETISO nxumatex4.dat Isotropic, temperature dependentETORTHO nxumatex5.dat Orthotropic, temperature dependentETANISO nxumatex6.dat Anisotropic, temperature dependentNLPLAST nxumatex7.dat Plasticity, temperature dependentNLCREEP nxumatex8.dat Creep, temperature dependent

PLASCR nxumatex9.dat Plasticity and creep combined, temperaturedependent

Material library path

There are three ways, in the following order of precedence, in which you can point NX Nastran tothe location of your material library.

• You can define the new keyword umatlib on either the command line or in your RCF file. Forexample,

umatlib=D:/scratch/mymaterial.dll

• You can define the new environment variable NXN_LOCAL_LIB_NAME. For example,

NXN_LOCAL_LIB_NAME D:/scratch/mymaterial.dll

• If you are run NX Nastran on a Windows machine, you can replace the following file with yourcompiled routine:installation_location\nxn11\em64tntl\libnxumat.dll

If you are run NX Nastran on a Linux machine, you can replace the following file with yourcompiled routine:installation_location\nxn11\x86_64linuxl\libnxumat.so

Debugging

You can debug a .dll file using Visual Studio on Windows as long as you build the .dll file with theoptions required for debugging. The .dll file you use for debugging can be built with the make_dll.bator the nmake utility.You can use the following procedure to debug.

1. NX Nastran must be configured so that it reads its input options from a file instead of thecommand line. You will create an *.asg file which contains the configuration options. The *.asgfile will include options such as the input file name, memory settings, and optionally the umatlibkeyword defining the path to the .dll.You can use the following procedure to create an *.asg file.

a. Set the environment variable NXN_NOEXE=1.

set NXN_NOEXE=1

b. Define your Material library path. Run an NX Nastran job using the input file which includesyour MUMAT bulk entry. When the variable NXN_NOEXE=1 is defined, NX Nastran will




generate the .asg file and stop. No solution will be performed. The .asg file generated willhave the name of the input file along with some process id information appended to it.

c. Reset the environment variable NXN_NOEXE.

set NXN_NOEXE

2. You can start debugging with the command:

devenv installation_location\nxn11\em64tntL\analysis.exe

This will start a Visual Studio debug session for the NX Nastran executable, analysis.exe. Enter aproject name including the path when Visual Studio makes this requests. For example:

D:\umat\demof\analysis.sln

3. Select Save.

4. Visual Studio will start with a solution named analysis. Right-click on the solution and chooseproperties.

5. When the property form appears, enter the location of your *.asg file in the Arguments fieldin the Parameters section.

6. Select the File Open command, open the top level driver for the UMAT .dll. In this environment, itwill be the “nxumat.F” file. Scroll down to the first executable line of code, and set a break.

7. Select the “Start Debugging” icon (green triangle) or press the F5 key. NX Nastran should launchand the execution should stop at the break point which was set in the previous step.

8. The next time you want to debug, you can use the following command which uses the savedsolution and bypasses several of the initial steps.

devenv analysis.sln

9. If the run is terminated prematurely from within the debugger, you must delete the temporaryfiles in the work directory, for example, D:\workdir. Failure to do so will cause subsequentdebugging runs to fail.




STATVAR

Requests output of state variables with SOL 401.

Requests output of state variables used by a user material subroutine with SOL 401.FORMAT:

EXAMPLES:STATVAR=ALLSTATVAR(PRINT,PUNCH)=17

DESCRIBERS:

Describer Meaning




GRID Output at grid points on elements.

GAUSS Output at gauss points on elements.

BOTH Output at both grid and gauss points on elements.

ALL Requests output for all elements.

n Set identification number of a previously appearing SET command.The SET command lists element IDs. (Integer>0)

NONE No output requested.

REMARKS:1. Only supported in SOL 401.

Initial stress-strainThe option to define an initial stress or strain condition is available on all elements in SOL 401except for plane strain elements, generalized plane strain elements, solid composite elements, andrigid elements.

You define the initial stress or strain with the new INITS case control command, which selects the newINITS bulk entry. The INITS case control command must be defined globally, above the subcases. Itis reapplied in every static subcase.

The initial stress or strain available in NX Nastran 11 is consistent with other static loads since itresults in an initial unbalanced load condition in a static subcase. That is, it deforms a body where it isunconstrained, and produces a stress state where it is constrained.




The first row on the INITS bulk entry includes the following fields.

• The TYPE field defines the data type: TYPE=STRESS or TYPE=STRAIN

• The CSYS field selects the coordinate system for the stress or strain components. The default isthe basic coordinate system. CSYS = -1 can also be defined to select the material system.

• The LOC field defines the location:

LOC= GRID: Specifies that data is defined at grid points.

LOC= NOE: Specifies that data is defined on an element at grid locations. This can includecorner and/or midside grid locations.

You define the stress or strain data on the consecutive rows on the INITS entry. The softwareassumes the data is either engineering stress or engineering strain. The format of these rowsdepends on the data location defined in the LOC field, and the element type.

Format for the 3D solid elements CTETRA, CHEXA, CPENTA and CPYRAM:

Stress at grid points (TYPE=STRESS, LOC=GRID):GRID ID Sxx Syy Szz Sxy Syz Szx

....

Strain data at grid points (TYPE=STRAIN, LOC=GRID):GRID ID Exx Eyy Ezz Exy Eyz Ezx

...

Stress data at the element corners (TYPE=STRESS, LOC=NOE):ElemID GRIDID Sxx Syy Szz Sxy Syz Szx

...

Strain data at the element corners (TYPE= STRAIN, LOC=NOE):ElemID GRIDID Exx Eyy Ezz Exy Eyz Ezx

...

For the plane stress elements CPLSTS3, CPLSTS4, CPLSTS6, CPLSTS8, the software uses bothin-plane and out-of-plane initial strain values. Although, only in-plane initial stress values are used.For example, the following formats should be used when the plane stress elements are defined onthe XY plane, and the basic coordinate system (default) is used. For elements defined on the XZplane, Sxx, Szz, Szx or Exx, Eyy, Ezz, Ezx would be defined.

Stress data at grid points (TYPE=STRESS, LOC=GRID):GRID ID Sxx Syy Sxy

...

Strain data at grid points (TYPE=STRAIN, LOC=GRID):GRID ID Exx Eyy Ezz Exy

...

Stress data at the element corners (TYPE=STRESS, LOC=NOE):ElemID GRIDID Sxx Syy Sxy

...

Strain data at the element corners (TYPE= STRAIN, LOC=NOE):ElemID GRIDID Exx Eyy Ezz Exy

...




For the axisymmetric elements CQUADX4, CQUADX8, CTRAX3, CTRAX6, in-plane (radial andaxial) and out-of-plane (theta) initial stress or strain values are used by the software. For example,the following formats should be used when the axisymmetric elements are defined on the XY plane,and the basic coordinate system (default) is used. For elements defined on the XZ plane, Sxx,Szz, Szx or Exx, Ezz, Ezx should be defined.

Stress data at grid points (TYPE=STRESS, LOC=GRID):GRID ID Sxx Syy Szz Sxy

...

Strain data at grid points (TYPE= STRAIN, LOC=GRID):GRID ID Exx Eyy Ezz Exy

...

Stress data at the element corners (TYPE=STRESS, LOC=NOE):ElemID GRIDID Sxx Syy Szz Sxy

...

Strain data at the element corners (TYPE= STRAIN, LOC=NOE):ElemID GRIDID Exx Eyy Ezz Exy

...

For the plane stress and axisymmetric elements, if you select a coordinate system other than thebasic system in the CSYS field on the INITS entry, the software first transforms the data into the basicsystem, and then uses the components consistent with the formats described above.

The option to output the initial strains using the new OSTNINI case control command is available. Theoutput can be requested at either the grid or corner Gauss locations on elements. The OSTNINIcommand must be defined globally, and the output occurs once at the beginning of the solution. Thestrains are output in the basic coordinate system.

Additional information:

• Initial stress and strain can be defined on a subset of the model. The software assumes a valueof 0.0 at the locations where data is undefined. An exception is when data is undefined at amid-side grid point, and data is defined at both or either related corners. In this case, the softwareinterpolates a value for that mid-side grid point.

• The option to apply an initial stress or strain condition before applying other loads in an initialsubcase is available to help convergence. The first subcase should have Tend=0.0 on theTSTEP1 entry and no load set selected. The number of increments can optionally be definedwith NINC on the TSTEP1 entry to increment the initial stress or strain. When NINC=1 (default),the initial stress or strain is applied in a single step. When NINC>1, the initial stress or strain isramped. A service load cannot be defined when ramping initial stress or strain with NINC>1.

• The software converts an initial stress to an initial strain using the elastic modulus defined onthe MATi entries. If you define MATTi bulk entries to define the elastic modulus as temperaturedependent, the software uses the initial temperatures selected by the TEMPERATURE(INIT)case control command to evaluate the temperature dependent elastic modulus. Data on theMATS1 bulk entry, if defined, is not used to convert stress to strain.

• You can define multiple INITS bulk entries, each with a unique ID, and then combine themusing the new INITADD bulk entry. The INITADD entry is selected with the ID on the INITScase control. The INITS entries selected by the INITADD entry must be all TYPE=STRESS or




all TYPE=STRAIN. As a result, you cannot mix initial stress and initial strain definitions in thesame input file.

• If you define data on the same grid or element corner location, a fatal error occurs.




INITS

Selects an initial stress or strain set.

Selects an initial stress or strain set.FORMAT:

INITS=nEXAMPLES:

INITS=12

DESCRIBERS:

Describer Meaning

n Set identification number of an INITS or INITADD bulk entry.(Integer>0)

REMARKS:1. INITS is only supported in SOL 401.

2. The INITS case control must be defined above the subcases (globally), and isreapplied in each static subcase. If you want to include the effects of initial stressor strain including any other load in a normal modes subcase, you should includea static subcase before the sequentially dependent normal modes subcase.




INITS

Defines initial stress or strain state in SOL 401.

Defines initial stress or strain state in SOL 401.FORMAT OF

INITIALSTRESS

DEFINED ONGRID POINTS(TYPE=STRESS

ANDLOC=GRID):

1 2 3 4 5 6 7 8 9 10

INITS SID STRESS GRID CSYS

GRID ID Sxx Syy Szz Sxy Syz Szx

GRID ID Sxx Syy Szz Sxy Syz Szx

... ... ... ... ... ... ...

FORMAT OFINITIALSTRESS

DEFINED ATELEMENT

GRIDLOCATIONS

(TYPE=STRESSAND LOC =

NOE):

1 2 3 4 5 6 7 8 9 10

INITS SID STRESS NOE CSYS

Elem ID GRID ID Sxx Syy Szz Sxy Syz Szx

Elem ID GRID ID Sxx Syy Szz Sxy Syz Szx

... ... ... ... ... ... ... ...

FORMAT OFINITIALSTRAIN

DEFINED ONGRID POINTS(TYPE=STRAIN

ANDLOC=GRID):

1 2 3 4 5 6 7 8 9 10

INITS SID STRAIN GRID CSYS

GRID ID Exx Eyy Ezz Exy Eyz Ezx

GRID ID Exx Eyy Ezz Exy Eyz Ezx

... ... ... ... ... ... ...




FORMAT OFINITIAL

STRAIN ATELEMENT

GRIDLOCATIONS

(TYPE=STRAINAND LOC =

NOE):

1 2 3 4 5 6 7 8 9 10

INITS SID STRAIN NOE CSYS

Elem ID GRID ID Exx Eyy Ezz Exy Eyz Ezx

Elem ID GRID ID Exx Eyy Ezz Exy Eyz Ezx

... ... ... ... ... ... ... ...

EXAMPLE:

1 2 3 4 5 6 7 8 9 10

INITS SID STRAIN NOE 0

12 3 .0045 .0342 .00015

12 28 .00012 .0035 .00015

12 65 .00012 .0035 .00015

12 72 .00012 .0035 .00015

FIELDS:

Field Contents

SID Initial stress or strain set identification number. (Integer>0; alsosee Remark 3)

TYPE Defines if the defined data is initial stress or initial strain. Thereis no default value for this field. This field must be defined.(Character)

= STRAIN for initial strain.

= STRESS for initial stress.

LOC The location where the data is defined. There is no default valuefor this field. This field must be defined. (Character)

= GRID for data on grid points.

= NOE for data on an element at grid locations. This can includecorner and/or midside grid locations.




Field Contents

CSYS Selects a coordinate system to define the initial stress or strainorientation. (Integer)

= -1 Material coordinate system is used.

= 0 Basic coordinate system is used. (Default)

> 0 Selects a specific CSYS.

Exx,Eyy,Ezz,

Exy,Eyz,Ezx

Engineering strains representing the symmetric portion of thestrain tensor. (Real)

Sxx,Syy,Szz,

Sxy,Syz,Szx,

Engineering stress representing the symmetric portion of thestress tensor. (Real)

When LOC=GRID:

GRID ID Grid point ID where data is applied. (Integer>0)

When LOC=NOE:

Elem ID Element where the data is applied. (Integer>0)

GRID ID Grid point ID defining a location on the element. (Integer>0)

REMARKS:1. The ID of all INITS and INITADD entries must be unique.

2. The option to define an initial stress or strain is available on all elements in SOL401 except for the plane strain elements including the generalized plane strainelements, solid composite elements defined with the PCOMPS entry, and rigidelements.

3. The INITS case control must be defined above the subcases (globally), and isreapplied in each static subcase. If you want to include the effects of initial stressor strain including any other load in a normal modes subcase, you should includea static subcase before the sequentially dependent normal modes subcase.

4. For the plane stress and axisymmetric elements, if you select a coordinate systemother than the basic system in the CSYS field on the INITS entry, the software firsttransforms the data into the basic system, then uses the components consistentwith the formats described below.

For the plane stress elements CPLSTS3, CPLSTS4, CPLSTS6, CPLSTS8, bothin-plane and out-of-plane initial strain values are used by the software. Although,only in-plane initial stress values are used. For example, when the plane stresselements are defined on the XY plane and the basic coordinate system is usedto define the initial stress or strain, Sxx, Syy, Sxy or Exx, Eyy, Ezz, Exy shouldbe defined. For elements defined on the XZ plane, Sxx, Szz, Szx or Exx, Eyy,Ezz, Ezx should be defined.




For the axisymmetric elements CQUADX4, CQUADX8, CTRAX3, CTRAX6,in-plane (radial and axial) and out-of-plane (theta) initial stress or strain valuesare used by the software. For example, when the axisymmetric elements aredefined on the XY plane and the basic coordinate system is used to define theinitial stress or strain, Sxx, Syy, Szz, Sxy or Exx, Eyy, Ezz, Exy should be defined.For elements defined on the XZ plane, Sxx, Syy, Szz, Szx or Exx, Eyy, Ezz, Ezxshould be defined.

5. Initial stress and strain can be defined on a subset of the model. The softwareassumes a value of 0.0 at the locations where data is undefined. An exceptiionis when data is undefined at a mid-side grid point, and data is defined at both oreither of the related corners. In this case, the software will interpolate a value forthat mid-side grid point.

6. The software converts initial stress to strain using the elastic modulus.Stress/strain data and the yield point on the MATS1 bulk entry, if defined, are notused to convert stress to strain.

7. Multiple INITS bulk entries can be defined, each with a unique ID, then combinedwith the INITADD entry. The INITADD entry is selected with the ID on the INITScase control. The INITS entries selected by the INITADD entry must be allTYPE=STRESS or all TYPE=STRAIN. As a result, you cannot mix initial stressand initial strain definitions in the same input file.

8. If data is defined on the same grid or element location, a fatal error will occur.




INITADD

Combines multiple initial stress or initial strain sets in SOL 401.

Combines multiple initial stress or initial strain sets in SOL 401.FORMAT:

1 2 3 4 5 6 7 8 9 10

INITADD SID

SID1 SID2 SID3 SID4 SID5 SID6 SID7 SID8

SID9 SID10 ...

EXAMPLE:

INITADD 80

100 101 102 103 104 105 106 107

108

FIELDS:

Field Contents

SID Set identification number for INITADD bulk entry. (Integer > 0)

SIDi Set identification number of INITS bulk entries. (Integer > 0)

REMARKS:1. The ID of all INITS and INITADD entries must be unique.

2. The INITS case control must be defined above the subcases (globally). If youwant to include the effects of initial stress or strain in a modal subcase, you shouldinclude a static subcase before the sequentially dependent modal subcase.

3. The INITS entries selected by the INITADD entry must be all TYPE=STRESSor all TYPE=STRAIN. You cannot mix initial stress and initial strain definitionsin the same input file.

4. If data is defined on the same grid or element corner location, a fatal error willoccur.




OSTNINI

Requests initial strain output in SOL 401.

Requests initial strain output in SOL 401.FORMAT:

EXAMPLES:OSTNINI=ALLOSTNINI(PRINT,PUNCH)=17

DESCRIBERS:

Describer Meaning




GRID Output at grid points on elements.

GAUSS Output at gauss points on elements.

BOTH Output at both grid and gauss points on elements.

ALL Requests output for all elements.

n Set identification number of a previously appearing SET command.The SET command lists element IDs. (Integer>0)

NONE No output requested.

REMARKS:1. Only supported in SOL 401.

2. The OSTNINI command should be defined above the subcases (globally). Theoutput only occurs once, at the beginning of the solution before any subcasesolutions begin.

3. Strains reported are engineering strain.

4. Initial strains are written to the .op2 file in the OES data block in SORT1 format.

5. The strain components are output in the basic coordinate system.




Time-varying added stiffness for generalized plane strain elementsGeneralized plane strain formulations for CPLSTNi elements became available in NX Nastran 10for use in SOL 401. To obtain the generalized plane strain behavior, the CPLSTNi element mustreference a PGPLSN property bulk entry. On the PGPLSN entry, you can specify constant addednormal and rotational stiffness for the generalized plane strain element.

Beginning with NX Nastran 11, the generalized plane strain capability is enhanced so that you cannow specify time-varying added normal and rotational stiffness terms. To do so, in an added stiffnessfield on the PGPLSN entry, enter the identification number of a TABLEDi bulk entry. On the TABLEDientry, list tabular data to define how the added stiffness term varies with time.

For more information, see the PGPLSN bulk entry.




PGPLSN

Generalized Plane Strain Element Property for SOL 401

Defines the properties of generalized plane strain elements for SOL 401.FORMAT:

1 2 3 4 5 6 7 8 9 10

PGPLSN PID MID CGID T

KN KR1 KR2

EXAMPLE:

PGPLSN 100 1 85 10.0

FIELDS:

Field Contents

PID Property identification number. See Remarks 1 and 2. (Integer > 0)

MID Identification number of a MAT1 or MAT11 entry. (Integer > 0; No default)

CGID Identification number of control grid point. (Integer > 0; No default)

T Undeformed element thickness. (Real > 0.0; No default)

KN Optional user-specified additive normal stiffness relative to the planararea defined by the mesh of generalized plane strain elements. (Real ≥0.0 or Integer > 0; Default = 0.0)

If real entry, value of stiffness at all times.

If integer entry, identification number of a TABLEDi entry that containsvalue of stiffness as a function of time.

KRi Optional user-specified additive rotational stiffness in the unitsmoment/radian about the ith-axis of the displacement coordinate systemfor the control grid point. See Remark 3. (Real ≥ 0.0 or Integer > 0;Default = 0.0)

If real entry, value of stiffness at all times.

If integer entry, identification number of a TABLEDi entry that containsvalue of stiffness as a function of time.

REMARKS:1. All PGPLSN property bulk entries must have unique identification numbers with

respect to all other property bulk entries.

2. PGPLSN bulk entries can only be referenced by CPLSTN3, CPLSTN4, CPLSTN6,and CPLSTN8 element bulk entries for SOL 401. When these elements referencea PGPLSN bulk entry, their generalized plane strain formulation is used.




3. Any planar area contains a pair of principal axes. The values for the optionaluser-specified additive rotational stiffness should be defined about axes that passthrough the control point and are parallel to the principal axes of the planar areadefined by the mesh of generalized plane strain elements. To do this, specify adisplacement coordinate system for the control grid point and define two of theaxes for the displacement coordinate system as parallel to the principal axesof the planar area as follows:

• If the axisymmetric plane is the XY-plane of the basic coordinate system,define the X- and Y-axes of the displacement coordinate system as parallel tothe principal axes of the planar area.

• If the axisymmetric plane is the XZ-plane of the basic coordinate system,define the X- and Z-axes of the displacement coordinate system as parallel tothe principal axes of the planar area.

4. The generalized plane strain element is not supported in a glue or contact region.

Chocking elementsBeginning with NX Nastran 11, you can use chocking elements in SOL 401 axisymmetric analysis.

Chocking elements are a special type of axisymmetric element that are used to model regions inan axisymmetric analysis that can carry a compressive hoop stress, but cannot carry a tensile hoopstress. Chocking elements behave like axisymmetric elements when a compressive hoop stress ispresent; otherwise, they behave like plane stress elements.

Chocking elements complement the existing modeling capabilities of axisymmetric elements andplane stress elements as follows:

• Axisymmetric elements are used to model regions that carry a hoop stress.

• Plane stress elements may be used to model regions in an axisymmetric analysis that do notcarry a hoop stress.

Like plane stress elements in axisymmetric analysis, you use chocking elements to model regionswhere the axisymmetric geometry is violated by regularly-spaced features like holes or keyways.However, you use chocking elements where the potential for a compressive hoop stress exists.

Tip

As a rule, only use chocking elements in combination with axisymmetric elements. A meshcomprised solely of chocking elements may lead to singularities, convergence issues, anderroneous results.

An example is the shrouding around the periphery of turbine blades in an aircraft engine.




A generic turbine assembly is shown in the figure. You can see that the shroud is constructed fromdiscrete segments that are attached to each turbine blade. A small gap exists between each segment.If the combination of mechanical and thermal loads is such that these gaps close, the shroud cansustain a compressive hoop stress. To account for this behavior in an axisymmetric model, you canmesh the shroud cross section with chocking elements.

The behavior of chocking elements depend on whether large displacements are enabled.

Linear analysis

When large displacements are not enabled, the gap status at the beginning of the analysis is usedthroughout the analysis. At any Gauss point location where there is no initial gap, the contributionto the elemental stiffness matrix from that Gauss point is based on the axisymmetric formulation ofthe chocking element.

Note

The axisymmetric formulation of chocking elements sustains tensile, as well ascompressive hoop stress. Because the gap distance does not update in a linear analysis,overly stiff results can occur for loadings that tend to increase the gap distance.

At any Gauss point location where there is an initial gap, the contribution to the elemental stiffnessmatrix from that Gauss point is based on the axisymmetric formulation of the chocking element withthe Eθ, νθr, and νθz elastic constants reduced by a factor of 1 x 106. Doing so causes the elementstiffness to be essentially identical to a plane stress formulation with σθ as the out-of-plane normalstress.

When large displacements are not enabled, the stiffness does not reformulate unless plasticity isenabled. When this occurs, the stiffness reformulates to account for plasticity effects only.

Geometric nonlinear analysis

When large displacements are enabled, the solution is iterative. For the initial iteration, at any Gausspoint location where there is no initial gap, the contribution to the elemental stiffness matrix from thatGauss point is based on the axisymmetric formulation of the chocking element. At any Gauss pointlocation where there is an initial gap, the contribution to the elemental stiffness matrix from thatGauss point is based on the axisymmetric formulation of the chocking element with the Eθ, νθr, andνθz elastic constants reduced by a factor of 1 x 106. Doing so causes the element stiffness to be




essentially identical to a plane stress formulation with σθ as the out-of-plane normal stress. From thisstiffness formulation and the prevailing mechanical and thermal loads, the software calculates theout-of-plane engineering strain, εθ, at each Gauss point for the initial iteration.

An expression for the gap size at the end of the iteration for each Gauss point is obtained as follows:

1. In the deformed configuration, the circumferential distance occupied by the chocking elementis given by

2πr – Ng

where N is the number of gaps, g is the gap size at the end of the iteration and r is the radiusat the end of the iteration.

2. Because εθ is an engineering strain, and engineering strains are based on undeformed lengths,the circumferential distance occupied by the chocking element in the deformed configurationis also given by

(1 + εθ) (2πr0 – Ng0)

where r0 is the initial radius and g0 is the initial gap size.

3. Equating the above terms for the circumferential distance occupied by the chocking element inthe deformed configuration and solving for the gap size at the end of the iteration yields

g = (1 / N) [2πr – (1 + εθ) (2πr0 – Ng0)]

Using this expression for the gap size at the end of the iteration, the software calculates whether ateach Gauss point the element is chocked (g ≤ 0) or unchocked (g > 0).

The second and all successive iterations use the gap status at the end of the previous iteration toformulate the stiffness for the current iteration. If the element is chocked at a Gauss point, thecontribution to the elemental stiffness matrix from that Gauss point for that iteration is based on theaxisymmetric formulation of the chocking element. If the element is unchocked at a Gauss point, thecontribution to the elemental stiffness matrix from that Gauss point for that iteration is based on theaxisymmetric formulation of the chocking element with the Eθ, νθr, and νθz elastic constants reducedby a factor of 1 x 106. Doing so causes the element stiffness to be essentially identical to a planestress formulation with σθ as the out-of-plane normal stress.

For applications of chocking elements like the turbine shroud, the mesh of chocking elements isconnected to axisymmetric elements. Because the stiffness in the radial direction for such a modelis relatively large, even when a positive gap exists, the incremental radial displacements that thesoftware calculates during the iterative solution are relatively small and the solution is able toconverge.

However, if the model is extremely compliant in the radial direction, the radial coordinates that thesoftware calculates to reformulate the stiffness may be negative, which is physically impossible.When the software detects a negative radial coordinate, it does not reformulate the stiffness matrixand it uses the initial circumferential distance for the deformed configuration at the next iteration.

To enable large displacements, specify PARAM,LGDISP,+1 in the input file.




Surface tractions on chocking elements

Use the PLOADX1 bulk entry to apply surface tractions to the edges of chocking elements. When thesoftware calculates the equivalent grid point forces from the surface traction data on a PLOADX1bulk entry, it accounts for the presence of gaps.

For example, suppose you use a PLOADX1 bulk entry to apply a pressure along the edge of achocking element. If the edge is directed in the axial direction, the total force applied to the chockingelement over 2π radians is:

p (2πr – Ng) L

where p is the pressure, r is the radial coordinate of the edge, N is the number of gaps, g is the gapsize, and L is the length of the edge.

Chocking element types

Four new elements are created to support the chocking capability:

• CCHOCK3 – A triangular chocking element

• CCHOCK4 – A quadrilateral chocking element

• CCHOCK6 – A triangular chocking element with midside nodes

• CCHOCK8 – A quadrilateral chocking element with midside nodes

All four chocking elements must reference the new PCHOCK property bulk entry. On the PCHOCKbulk entry, you specify the material property for the chocking element and the number of gaps. Youcan specify the initial gap thickness on either the PCHOCK bulk entry or on the chocking elementbulk entries that reference the PCHOCK bulk entry. If the initial gap thickness is specified on both, thespecification on the chocking element bulk entry takes precedence. If the gap is of uniform thickness,use the GAPT field on the PCHOCK bulk entry to specify the gap thickness. If the gap thicknessvaries through the cross section, use the GAPi fields on the chocking element bulk entries, or use acombination of GAPT specifications and GAPi overrides, to specify the gap thickness.

To request gap results output, use the new CKGAP case control command.

For more information, see the new CCHOCK3, CCHOCK4, CCHOCK6, CCHOCK8, and PCHOCKbulk entries, and the new CKGAP case control command.




CKGAP

Gap Result Output Request

Requests gap result output for chocking elements in SOL 401.FORMAT:

EXAMPLES:CKGAP(GAUSS)=ALL

DESCRIBERS:

Describer Meaning

GRID Requests gap results for corner grids. (Default)

GAUSS Requests gap results for Gauss points.

BOTH Requests gap results for corner grids and Gauss points.

PRINT The printer is the output medium. (Default)

PUNCH The punch file is the output medium.

PLOT Generates results for requested set but no printer output.

ALL Results are output for all chocking elements.

n Identification number of a SET case control command that lists thechocking elements for which results are output. (Integer>0)

NONE No results are output for any chocking elements.

REMARKS:1. The software uses the gap result at the gauss points to determine if the element is

chocked or unchocked.

2. Gap results at the grid points is computed using a linear extrapolation of the gapresults at the gauss points. Since gap results can vary across the elements,the linear extrapolation can introduce inaccurate gap results at the grid points.This becomes more significant when there is a large variation of gap across anelement, which is possible with a coarse mesh.




CCHOCK3

2D Chocking Triangular Element Connection

Defines a 2D chocking triangular element connection. Valid for SOL 401 axisymmetricanalysis only.

FORMAT:

1 2 3 4 5 6 7 8 9 10CCHOCK3 EID PID G1 G2 G3 THETA

GAP1 GAP2 GAP3

EXAMPLE:

CCHOCK3 19 9 1215 1216 1342

0.001 0.0

FIELDS:

Field Contents

EID Element identification number. (Integer > 0)

PID Property identification number of a PCHOCK bulk entry.(Integer > 0; No default)

Gi Grid point identification number of connection points. (Integer> 0; No default)

THETA Material property orientation angle in degrees. See Remark4. (Real; Default = 0.0)

GAPi Initial gap opening at grid point Gi. See Remark 6. (Real orblank; See Remark 5 for default behavior)

REMARKS:1. Element identification numbers should be unique with respect to all other element

identification numbers.

2. The grid points of all axisymmetric elements (CTRAX3, CQUADX4, CTRAX6,CQUADX8, CCHOCK3, CCHOCK4, CCHOCK6, CCHOCK8), plane stresselements (CPLSTS3, CPLSTS4, CPLSTS6, CPLSTS8), and plane strain elements(CPLSTN3, CPLSTN4, CPLSTN6, CPLSTN8) must all lie in either the XZ-plane,or all in the XY-plane of the basic coordinate system.

3. The basic coordinate system is the reference coordinate system for stress andstrain output.

4. For orthotropic materials, the THETA angle orients the principal materialcoordinates of the element relative to the basic coordinates. Figures 5-1 and 5-2




show the positive sense of the THETA angle when the element is defined on theXZ-plane and XY-plane, respectively.

5. If GAPi is blank, the value for GAPT on the corresponding PCHOCK entry is usedfor the initial gap opening at grid point Gi. If GAPi and GAPT on the correspondingPCHOCK entry are both specified, the GAPi specification takes precedence. Thesoftware computes the total initial gap opening at grid point Gi as the product ofGAPi (or GAPT) and the value for NGAP on the corresponding PCHOCK entry.

6. If the value for GAPi or, if applicable, the value for GAPT on the correspondingPCHOCK entry is negative, the software uses the value to calculate an initialcompressive hoop strain.

7. For any grid point Gi selected on axisymmetric, plane stress, or plane stainelements, if you select a displacement coordinate system with the CD field onthe GRID entry, you must orient the displacement coordinate system accordingto the following rules:

• If the elements are defined on the XY-plane of the basic coordinate system, theZ-axis (φ-axis for a spherical system) of the displacement coordinate systemmust be in the same direction as the Z-axis of the basic coordinate system.

• If the elements are defined on the XZ-plane of the basic coordinate system,the Y-axis (θ-axis for the cylindrical and spherical systems) of the displacementcoordinate system must be in the same direction as the Y-axis of the basiccoordinate system.

8. GPSTRESS and GPSTRAIN output are not supported.

9. The behavior of chocking elements depend on whether large displacements areenabled.

• When large displacements are not enabled, the gap status at the beginningof the analysis is used throughout the analysis and the stiffness does notreformulate unless plasticity is enabled. When plasticity is enabled, thestiffness reformulates to account for plasticity effects only.

• When large displacements are enabled, the solution is iterative. The initial gapstatus is used for the first iteration. The gap status at the end of each iterationis updated and the stiffness is reformulated. When plasticity is enabled, thestiffness reformulates to account for plasticity effects, as well as changesin gap status.


10. At any Gauss point location where there is no gap, the contribution to the elementalstiffness matrix for the chocking element from that Gauss point is based on theaxisymmetric formulation of the chocking element. At any Gauss point locationwhere there is a gap, the contribution to the elemental stiffness matrix for thechocking element from that Gauss point is based on the axisymmetric formulationof the chocking element with the Eθ, νθr, and νθz elastic constants reduced by a




factor of 1 x 106 so that the element stiffness becomes essentially identical to aplane stress formulation with σθ as the out-of-plane normal stress.

Figure 5-1. CCHOCK3 Element Geometry and Coordinate Systems, XZ-Plane

Figure 5-2. CCHOCK3 Element Geometry and Coordinate Systems, XY-Plane




CCHOCK4

2D Chocking Quadrilateral Element Connection

Defines a 2D chocking quadrilateral element connection. Valid for SOL 401axisymmetric analysis only.

FORMAT:

1 2 3 4 5 6 7 8 9 10CCHOCK4 EID PID G1 G2 G3 G4 THETA

GAP1 GAP2 GAP3 GAP4

EXAMPLE:

CCHOCK4 19 9 1215 1216 1342 1222

0.001 0.0 0.002

FIELDS:

Field Contents








2. The grid points of all axisymmetric elements (CTRAX3, CQUADX4, CTRAX6,CQUADX8, CCHOCK3, CCHOCK4, CCHOCK6, CCHOCK8), plane stresselements (CPLSTS3, CPLSTS4, CPLSTS6, CPLSTS8), and plane strain elements(CPLSTN3, CPLSTN4, CPLSTN6, CPLSTN8), must all lie in either the XZ-plane,or all in the XY-plane of the basic coordinate system.






CCHOCK6

2D Chocking Triangular Element Connection

Defines a 2D chocking triangular element connection. Valid for SOL 401 axisymmetricanalysis only.

FORMAT:

1 2 3 4 5 6 7 8 9 10CCHOCK6 EID PID G1 G2 G3 G4 G5 G6

THETA GAP1 GAP2 GAP3

EXAMPLE:

CCHOCK6 237 1 1215 1217 1342 1216 1289 1290

30.0 0.001 0.0

FIELDS:

Field Contents














CCHOCK8

2D Chocking Quadrilateral Element Connection

Defines a 2D chocking quadrilateral element connection. Valid for SOL 401axisymmetric analysis only.

FORMAT:

1 2 3 4 5 6 7 8 9 10CCHOCK8 EID PID G1 G2 G3 G4 G5 G6

G7 G8 THETA GAP1 GAP2 GAP3 GAP4

EXAMPLE:

CCHOCK8 19 9 1215 1217 1442 1440 1216 1886

1441 1385 30.0 0.001 0.0 0.002

FIELDS:

Field Contents

















7. For any grid point Gi selected on axisymmetric, plane stress, plane stain, orchocking elements, if you select a displacement coordinate system with the CDfield on the GRID entry, you must orient the displacement coordinate systemaccording to the following rules:












PCHOCK

Defines Properties for 2D Chocking Elements

Defines properties for CCHOCKi elements.FORMAT:

1 2 3 4 5 6 7 8 9 10PCHOCK PID MID NGAP GAPT

EXAMPLE:

PCHOCK 100 1 6 1.0

FIELDS:

Field Contents

PID Property identification number. (Integer > 0)

MID Material identification number for a MAT1 or MAT11 bulk entry. (Integer> 0; No default)

NGAP Number of gaps. (Integer > 0; No default)

GAPT Initial gap opening. See Remarks 1, 2, and 3. (Real; Default = 0.0)

REMARKS:1. The value for GAPT is used for all grid points Gi in the connectivity of chocking

elements that reference the PCHOCK entry, except for those grid points Gi whereGAPi on the chocking element bulk entry is specified. For those grid points, theGAPi value takes precedence.

2. If the value for GAPT or, if applicable, the value for GAPi on the correspondingCCHOCKi entry is negative, the software uses the value to calculate an initialcompressive hoop strain.

3. Figure 5-9 shows a possible application for chocking elements and how the initialgap opening GAPT is defined.




Figure 5-9. Initial Gap Opening

Cohesive elementsBeginning with NX Nastran 11, when using SOL 401 you can use cohesive elements to modeladhesively bonded interfaces. The advantages of cohesive elements over traditional glue connectionsin NX Nastran are that with cohesive elements, you can account for:

• Compliance in the connection.

• Damage in the material.

To support the cohesive element capability, the CHEXCZ and CPENTCZ elements are introduced.You can define these elements as occupying a solid volume or a planar area. To define the elementgeometry such that it occupies a planar area, define coincident grid points on each edge thatconnects the top and bottom faces.

For example, to define the CPENTCZ element as a planar area, G1, G10, and G4 must have thesame coordinates. G1 is also included in the connectivity of an element that is part of the mesh onone side of the interface and G4 is also included in the connectivity of an element that is part of themesh on the other side of the interface. Mid-side grid points on edges that connect the top andbottom faces like G10 are exclusive to the cohesive element mesh.

CHEXCZ and CPENTCZ elements must reference a PSOLCZ property. With the PSOLCZ bulk entry,you reference the corresponding MAT1, MAT11, or MATCZ bulk entry, the material coordinate system,and, under certain circumstances, the thickness of the element.

There are three stiffness values associated with cohesive elements: K01 and K02 are the transverseshear stiffness; K03S is the out-of-plane normal stiffness. You specify these stiffness values asfollows:

• If the PSOLCZ bulk entry references a MAT1 bulk entry, NX Nastran calculates the stiffness ofthe cohesive elements to be K01 = G / THICK, K02 = G / THICK, and K03S = E / THICK, whereTHICK is the value you specify in the THICK field of the PSOLCZ bulk entry.

• If the PSOLCZ bulk entry references a MAT11 bulk entry, NX Nastran calculates the stiffness ofthe cohesive elements to be K01 = G13 / THICK, K02 = G23 / THICK, and K03S = E3 / THICK,where THICK is the value you specify in the THICK field of the PSOLCZ bulk entry.




• If the PSOLCZ bulk entry references a MATCZ bulk entry, you specify the stiffness directly inthe K01, K02, and K03S fields of the MATCZ bulk entry. For this case, the THICK field of thePSOLCZ bulk entry is ignored.

In all three cases, NX Nastran does not use the physical thickness of cohesive elements as definedby the geometric coordinates of the grids to determine the stiffness of the cohesive element.

You use the new MATCZ bulk entry when you want to obtain material damage estimates. To activatedamage estimation, include PARAM,MATNL,1 in your input file. On the MATCZ bulk entry, specify thedamage estimation model. You can choose from the following options:

• In the polynomial model (the default), the Mode I, Mode II, and Mode III damage variables aretaken to be equal, and the damage is modeled as a function of thermodynamic force. Anevolution equation is used to estimate the damage.

• In the bi-triangular model, for Mode I, the relationship between stress and displacement ismodeled as bilinear.

• In the exponential model, for Mode I, the relationship between stress and displacement ismodeled as exponential.

NX Nastran also does not use the physical thickness of cohesive elements as defined by thegeometric coordinates of the grids in damage calculations.

Results for cohesive elements are calculated at the corner grid points. The results include:

• Damage values

• Surface tractions

• Relative displacements

To request result output for cohesive elements, use the CZRESULTS case control command.With the CZRESULTS case control command, you can obtain the damage for all three modes,components of the surface tractions, and components of the relative displacements. Relativedisplacement is defined as the displacement of the top surface of the cohesive element relativeto the bottom surface of the cohesive element.

Four values are reported for surface tractions and relative displacements. One value is the magnitudeof the surface traction or relative displacement in the direction normal to the element. The otherthree values are the components relative to the basic coordinate system of the surface traction orrelative displacement in the plane of the element. Surface tractions have units of force per unitarea. Relative deformation has units of length.

For more information, see the new CZRESULTS case control command, and the new CHEXCZ,CPENTCZ, PSOLCZ, and MATCZ bulk entries.




CZRESULTS

Cohesive Element Output Request

Requests results output for cohesive elements in SOL 401.FORMAT:

EXAMPLES:CZRESULTS(DAMAGE,PUNCH)=100

DESCRIBERS:

Describer Meaning

TRACTION Requests normal and in-plane traction results. See Remarks 1and 2. (Default)

RLTDIS Requests normal and in-plane relative displacement results. SeeRemarks 1 and 2.

DAMAGE Requests damage results. See Remark 1.




ALL Results are output for all cohesive elements.

n Identification number of a SET case control command that lists thecohesive elements for which results are output. (Integer>0)

NONE No results are output for any cohesive elements.

REMARKS:1. All results are reported at the corner grid points.

2. Four values are reported for tractions and relative displacements. One value isthe magnitude of the traction or relative displacement in the direction normal tothe element. The other three values are the components relative to the basiccoordinate system of the traction or relative displacement in the plane of theelement. Tractions have units of force per unit area. Relative deformation hasunits of length.




CHEXCZ

Six-Sided Cohesive Element Connection

Defines the connections of the six-sided cohesive element with eight to twenty gridpoints.

FORMAT:

1 2 3 4 5 6 7 8 9 10CHEXCZ EID PID G1 G2 G3 G4 G5 G6

G7 G8 G9 G10 G11 G12 G13 G14

G15 G16 G17 G18 G19 G20

EXAMPLE:

CHEXCZ 15 1 3 4 5 6 7 8

9 10 0 30 31 53 54

55 56 57 58 59 60

FIELDS:

Field Contents


PID Property identification number of a PSOLCZ. (Integer > 0; Nodefault)

Gi Grid point identification numbers of connection points. (Integer> 0 or blank; See Remark 3 for default behavior)

Figure 5-10. CHEXCZ Element Connection






2. Grid points G1 through G4 must be given in consecutive order about onequadrilateral face. This is the bottom face of the element. G5 through G8 mustbe on the opposite face with G5 opposite G1, G6 opposite G2, G7 opposite G3,and G8 opposite G4. This is the top face of the element. The normal direction isdefined relative to the bottom surface.

3. The edge points G9 to G20 are optional. Any or all of them may be deleted. If theID of any edge connection point is left blank or set to zero (G9 and G10 in the inputexample), the equations of the element are adjusted to give correct results for thereduced number of connections. Corner grid points cannot be deleted.

4. If G15 through G20 are omitted, the second continuation line is not required.

5. For best results, locate edge grid points within the middle third of the edge.

6. For information regarding the material coordinate system, see PSOLCZ.




CPENTCZ

Five-Sided Cohesive Element Connection

Defines the connections of a five-sided cohesive element with six to fifteen grid points.

FORMAT:

1 2 3 4 5 6 7 8 9 10CPENTCZ EID PID G1 G2 G3 G4 G5 G6

G7 G8 G9 G10 G11 G12 G13 G14

G15

EXAMPLE:

CPENTCZ 112 2 3 15 14 4 103 115

5 16 8 0 120 125

130

FIELDS:

Field Contents


PID Property identification number of a PSOLCZ entry. (Integer > 0;No default)

Gi Identification numbers of connected grid points. (Integer ≥ 0 orblank; See Remark 3 for default behavior)

Figure 5-11. CPENTCZ Element ConnectionREMARKS:

1. Element identification numbers must be unique with respect to all other elementidentification numbers.




2. Grid points G1 through G3 must define one triangular face. This is the bottomface. G4 through G6 must be on the opposite face with G4 opposite G1, G5opposite G2, and G6 opposite G3. This is the top face. The normal direction isdefined relative to the bottom surface.

3. The edge points G7 to G15 are optional. Any or all of them may be omitted. If theID of any edge connection point is left blank or set to zero (G10, G11, and G12 inthe input example), the equations of the element are adjusted to give correct resultsfor the reduced number of connections. Corner grid points cannot be omitted.

4. If all edge grid points are omitted, the first and second continuation lines are notrequired. If G15 is the only edge grid point that is omitted, the second continuationline is not required.

5. For best results, locate edge grid points within the middle third of the edge.

6. For information regarding the material coordinate system, see PSOLCZ.




PSOLCZ

Properties of Cohesive Elements

Defines the properties of cohesive elements (CHEXCZ and CPENTCZ entries).FORMAT:

1 2 3 4 5 6 7 8 9 10

PSOLCZ PID MID CORDM THICK

EXAMPLE:

PSOLCZ 1 4 3 0.75

FIELDS:

Field Contents

PID Property identification number. (Integer > 0)

MID Identification number of a MAT1, MAT11, or MATCZ entry. SeeRemark 2. (Integer > 0; No default)

CORDM Identification number of the material coordinate system. Enter “0” orleave blank to use the basic coordinate system. See Remarks 3 and4. (Integer; Default = 0)

THICK Thickness of cohesive element. See Remark 2. (Real > 0.0; Default =1.0)

REMARKS:1. PSOLCZ entries should have unique identification numbers with respect to all

other property entries.

2. Three stiffness values are associated with cohesive elements: K01 and K02 aretransverse shear stiffness values; K03S is the out-of-plane normal stiffness value.

The physical thickness of a cohesive element as defined by the geometriccoordinates of the grids is not used to determine the stiffness of the cohesiveelement.

If the PSOLCZ entry references a MAT1 entry, the software calculates thestiffness of the cohesive elements to be K01 = G / THICK, K02 = G / THICK, andK03S = E / THICK.

If the PSOLCZ entry references a MAT11 entry, the software calculates the stiffnessof the cohesive elements to be K01 = G13 / THICK, K02 = G23 / THICK, andK03S = E3 / THICK.

If the PSOLCZ entry references a MATCZ entry, you specify the stiffness of thecohesive element directly in the K01, K02, and K03S fields of the MATCZ entryand the THICK field is ignored.




The unit of stiffness for cohesive elements is force per unit length cubed.

3. The Z-axis of the material coordinate system for a cohesive element is normal tothe plane defined by grids G1-G2-G3-G4 for a CHEXCZ element or the planedefined by grids G1-G2-G3 for a CPENTCZ element. The positive sense of theZ-axis is the same direction as the vector obtained by crossing a vector directedfrom G1 to G2 with a vector directed from G1 to G4 for the CHEXCZ element or avector directed from G1 to G3 for the CPENTCZ element.

The X-axis of the material coordinate system for a cohesive element depends onwhether a MATCID entry references the element.

• If a MATCID entry references the element, the X-axis of the materialcoordinate system is the projection of the X-axis of the coordinate systemlisted in the CID field of the MATCID entry onto the plane defined by gridsG1-G2-G3-G4 for a CHEXCZ element or the plane defined by grids G1-G2-G3for a CPENTCZ element.

• If a MATCID entry does not reference the element, the X-axis of the materialcoordinate system depends on how the CORDM field is specified.

o If the CORDM field is specified, but not set to "0", the X-axis of the materialcoordinate system is the projection of the X-axis of the CORDM coordinatesystem onto the plane defined by grids G1-G2-G3-G4 for a CHEXCZelement or the plane defined by grids G1-G2-G3 for a CPENTCZ element.

o If the CORDM field is blank or is set to "0", the X-axis of the materialcoordinate system is the projection of the X-axis of the basic coordinatesystem onto the plane defined by grids G1-G2-G3-G4 for a CHEXCZelement or the plane defined by grids G1-G2-G3 for a CPENTCZ element.

The Y-axis of the material coordinate system lies in the plane defined by gridsG1-G2-G3-G4 for a CHEXCZ element or the plane defined by grids G1-G2-G3for a CPENTCZ element, and together with the X-axis and Z-axis forms aright-handed coordinate system.




The software cannot project the X-axis of the CORDM, CID, or basic coordinatesystem onto the plane of a cohesive element if it is parallel to the Z-axis of thematerial coordinate system for the cohesive element. If they are parallel, a fatalerror results.

4. If MID references a MAT11 or MATCZ entry, then CORDM defines the principalmaterial coordinates.

5. Use the CZRESULTS case control command to request results for CHEXCZ andCPENTCZ elements. Results are output for corner grid points only.

6. A cohesive element can use temperature-dependent materials MAT1 and MATT1,or MAT11 and MATT11. However, logarithmic interpolation is not supported if aTABLEM1 is referenced. The software does not issue a warning message andreverts to linear interpolation if a logarithmic AXIS is specified.




MATCZ

Cohesive Element Material

Defines damage model and material properties for cohesive elements (CHEXCZand CPENTCZ).

FORMAT FORPOLYNOMIALLAW (DLAW =

“POLY”):

1 2 3 4 5 6 7 8 9 10MATCZ MID DLAW TANG TAU ADEL

K03S K02 K01 GIC GIIC GIIIC DCOU Y0SEXPN

FORMAT FORBI-TRIANGULARLAW (DLAW =

“BITR”):


K03S K02 K01 GIC GIIC GIIIC DCOU Y0S

FORMAT FOREXPONENTIALLAW (DLAW =

“EXPO”):


K03S K02 K01 GIC GIIC GIIIC DCOU

EXAMPLES:

MATCZ 1 POLY 1 1.5 3.04.0+8 1.0+8 1.0+8 0.32 0.48 0.48 1.0 0.10.5

MATCZ 1 BITR 14.0+8 1.0+8 1.0+8 0.32 0.48 0.48 1.0 0.1

MATCZ 1 EXPO 1 2.04.0+8 1.0+8 1.0+8 0.32 0.48 0.48 1.0

FIELDS:

Field Contents





Field Contents

DLAW Damage model. (Character; Default = “POLY”)

“POLY” for the Polynomial model.

“BITR” for the Bi-Triangular model.

“EXPO” for the Exponential model.

TANG Tangent of constitutive model. (Integer; Default = 1)

1: Use the tangent stiffness when it is positive and use zero when itis negative.

2: Use the secant stiffness.

3: Use the tangent stiffness.

TAU Time for delay. See Remark 2. (Real; Default = 0.0)

ADEL Parameter for delay. See Remark 3. (Real > 0.0; Default = 1.0)

K03S Out-of-plane normal stiffness in force per unit length3. (Real > 0; Nodefault)

K02 In-plane shear stiffness in force per unit length3. (Real > 0; No default)

K01 Transverse shear stiffness in force per unit length3. (Real > 0; Nodefault)

GIC Critical energy release rate for Mode I. (Real > 0; No default)

GIIC Critical energy release rate for Mode II. (Real > 0; No default)

GIIIC Critical energy release rate for Mode III. (Real > 0; No default)

DCOU Coupling coefficient. (Real ≠ 0.0)

Y0S Thermodynamic force. (Real ≥ 0.0)

EXPN Exponent. (Real > 0.0)

REMARKS:1. The material identification number must be unique with respect to the collection of

all MAT1, MAT11, and MATCZ entries.

2. Use a positive value to define time for delay. The software interprets negativevalues as zero time for delay.

3. If TAU ≤ 0.0, there is no time for delay and the ADEL field is ignored.




Progressive failure analysis in solid compositesBeginning with NX Nastran 11, you can model progressive ply failure in composite laminates that aremeshed with solid elements. This capability is available in SOL 401 only. NX Nastran 11 supportsa unidirectional ply failure model that is based on a model developed by Ladeveze and Le Dantec(Damage modeling of the elementary ply for laminated composites, Composites Science andTechnology 43, 1992) in which damage is linked to the transverse normal stress and in-plane shearstress. However, the model that is supported in NX Nastran can also account for:

• Damage in the fiber direction.

• Damage linked to the stresses in the out-of-plane direction.

• Damage linked to time delay effects.

• Coupling with plasticity.

• Stress/strain-dependent elastic modulus.

The procedure for estimating ply damage is iterative. Using the material properties in the undamagedstate, NX Nastran makes an initial calculation of the stress state. NX Nastran uses this stress state inthe unidirectional ply model to calculate an initial estimate of ply damage. Based on these damagevalues, NX Nastran calculates the material properties in the damaged state. With these values for thematerial properties, NX Nastran solves the model to obtain the updated stress state. NX Nastranuses the updated stress state in the unidirectional ply model to calculate a second estimate of the plydamage, and continues iterating until the ply damage values converge.

The converged damage values are termed the static damage. If you optionally include time delayeffects, the final damage values for the time step are the static damage values adjusted for thetime delay.

To use the progressive ply failure capability, model the laminate with CHEXA and CPENTA solidelements that reference PCOMPS bulk entries. In the MIDi fields of the PCOMPS bulk entries, enterthe MID of MAT11 bulk entries to define the linear elastic properties of the plies in the undamagedstate. To define the material properties and parameters that are related to progressive ply failuremodel, include MATDMG bulk entries that have the same MID as the MAT11 bulk entries. To obtainply failure results output, include a PFRESULTS case control command.

Because progressive ply failure is applicable to composite laminates that are meshed with solidelements, you can optionally use CHEXCZ and CPENTCZ cohesive elements to model the interfacebetween the solid elements.

For more information, see the new PFRESULTS case control command, the updated PCOMPSbulk entry, and the new MATDMG bulk entry.

Unidirectional ply model

The unidirectional ply model uses Equation 5-1 for the strain energy density at a point in a ply.Equation 5-1 accounts for damage to the ply and is used to formulate expressions for elementstiffness and thermodynamic force.




Equation 5-1.

where:

• The 1-direction is the fiber direction.

• The 2-direction is the in-plane transverse direction.

• The 3-direction is the out-of-plane transverse direction.

• d11, d22, and d12 are the damage variables.

• EI0, Gij0, and νij0 are the elastic modulus, shear modulus, and Poisson’s ratio, respectively forthe undamaged material.

• λ is a parameter whose value is either zero or one that controls whether or not damage is linkedto out-of-plane stresses.

Note

‹x›+ means use the value for x when x > 0, and use x = 0 when x ≤ 0. Similarly, ‹x›- meansuse the value for x when x < 0, and use x = 0 when x ≥ 0.

The unidirectional ply model uses thermodynamic forces to predict ply damage. Thermodynamicforces are derived from the strain energy density as indicated in Equation 5-2.

Equation 5-2.

The criteria that the unidirectional ply model uses to predict ply damage are indicated in Equation 5-3.




Equation 5-3.

where:

• dijs are the static damage values.

• Y11lim+ and Y11lim- are energy threshold values in tension and compression, respectively.

• Y120 is the energy threshold for shear damage d12.

• Y12C is the critical value of energy for shear damage d12.

• b3 is the coupling coefficient between damage variables.

In Equation 5-3, Ymax is defined from Equation 5-4.

Equation 5-4.

where t is the time at the end of the current time step.

In Equation 5-4, Y(t) is referred to as the equivalent thermodynamic force, and it is given by Equation5-5.

Equation 5-5.

where b2 is also a coupling coefficient.

In Equation 5-3, Y12F and Y22F are referred to as the thermodynamic forces in fragile behavior.They are defined by Equation 5-6.




Equation 5-6.

where η is the transition thickness of the ply, h is the thickness of the ply, and Y12S and Y22S arethe transverse fissuration thresholds.

Note

sup (supremum) evaluates to the least upper bound of the arguments.

Time delay effects

The unidirectional ply model can optionally include time delay effects. Time delay effects smooth theoccurrence of damage. Equation 5-7 shows how the rate of damage accumulation is calculated.

Equation 5-7.

where τc is a time constant, ac is a parameter for delay, and dmax is the maximum allowable valueof damage.

dijS are the static damage values calculated from Equation 5-3.

Coupling with plasticity

The unidirectional ply model includes coupling with plasticity. The plasticity calculations use theeffective stress definitions in Equation 5-8.




Equation 5-8.

The software uses the effective stresses in Equation 5-9 to predict when yielding occurs.

Equation 5-9.

where:

• a is the coupling coefficient.

• p is the cumulative plastic strain.

• R0 is the initial plasticity threshold.

• R(p) is the yield function.

The form of the yield function that the software uses is given by Equation 5-10.

Equation 5-10.

where K and γ are empirically-derived material constants.

The software calculates the rate of plastic strain accumulation from Equation 5-11.




Equation 5-11.

where:

Equation 5-12.

Nonlinear traction and compression

The unidirectional ply model can optionally include a nonlinear elastic modulus in the fiber directionas indicated in Equation 5-13.

Equation 5-13.

where ζ+ and ζ- are nonlinearity coefficients in tension and compression, respectively.

Specifying material properties and parameters for the unidirectional ply model

Table 5-117 shows where you specify the various material properties and parameters used in theunidirectional ply model.

Material property or parameter Bulk entry (field name)Ei0, Gij0, νij0 MAT11λ MATDMG (PE field)Y11lim+ MATDMG (Y11LIMT field)Y11lim- MATDMG (Y11LIMC field)Y120 MATDMG (Y012 field)Y12C MATDMG (YC12 field)b2 MATDMG (B2 field)




Material property or parameter Bulk entry (field name)b3 MATDMG (B3 field)η MATDMG (HBAR field)h PCOMPS (TRi field)Y12S MATDMG (YS12 field)Y22S MATDMG (YS22 field)τc MATDMG (TAU field)ac MATDMG (ADEL field)dmax MATDMG (DMAX field)a MATDMG (A field)R0 MATDMG (LITK field)K MATDMG (BIGK field)γ MATDMG (EXPN field)ζ+ MATDMG (KSIT field)ζ- MATDMG (KSIC field)




PFRESULTS

Progressive Failure Output Request

Requests progressive failure results output for composite solid elements in SOL 401.FORMAT:

EXAMPLES:PFRESULTS(DAMAGE,ENERGY,PLOT)=ALL

DESCRIBERS:

Describer Meaning

DAMAGE Requests damage value results. See Remarks 1 and 2. (Default)

STATUS Requests damage status. See Remark 3.

ENERGY Requests damage energy results. See Remark 4.




ALL Results are output for all composite solid elements.

n Identification number of a SET case control command that lists thecomposite solid elements for which results are output. (Integer>0)

NONE No results are output for any composite solid elements.

REMARKS:1. Results are reported at the corner grid points for each ply in the laminate on an

individual element basis. The results for each ply in the laminate are reportedat the middle of the ply.

2. Damage values are calculated at the Gauss points and extrapolated to the cornergrid points. At the Gauss points, the calculated damage can range from 0.0 and0.999. A damage value of 0.999 indicates that the elastic modulus is reducedto 0.1% of its original value. The software limits the damage to 0.999 to avoidnumerical problems that can arise if the damage is 1.0. However, because thevalues at the Gauss points are extrapolated to the corner grids, the reporteddamage values at the corner grids can be less than 0.0 and greater than 0.999.

3. Damage status is reported on an individual element basis as follows:

“0” indicates that the laminate is undamaged.

“1” indicates that some plies in the laminate are damaged, but have not failed.




“2” indicates that some plies in the laminate have failed and other plies in thelaminate may be damaged.

“3: indicates that all plies in the laminate have failed.

A ply has failed when the software calculates that the ply is damaged at all Gausspoints. A ply is damaged when the software calculates that the ply is damaged atone or more, but not all of the Gauss points.

4. Damage energy is the energy that is expended to cause the damage in thelaminate. Damage energy is output on an element-by-element basis.




PCOMPS

Layered Composite Element Property for Solid Elements

Defines the properties of an n-ply composite material laminate for CHEXA andCPENTA solid elements.

FORMAT:

1 2 3 4 5 6 7 8 9 10

PCOMPS PID CORDM PSDIR SB NB TREF GE

GPLYIDi MIDi TRi THETAi FTi ILFTi SOUTi

EXAMPLE:

PCOMPS 20 2 13 10000.

1 1 0.02 45. TSAI NB YES

2 1 0.03 –45. HILL SB YES

3 2 0.05 0. TSAI SB YES

4 1 0.03 –45. HILL SB YES

5 1 0.02 45. TSAI NB YES

FIELDS:

Field Contents

PID Property identification number. (0 < Integer < 10000000)

CORDM Identification number of the coordinate system that the software uses todetermine the orientation of the material coordinate system. See Remark1. Enter “0” or leave blank to use the basic coordinate system. (Integer;Default = 0)

PSDIR Ply and stack directions. Enter the X-, Y-, and Z-axes of CORDM as1, 2, and 3, respectively. See Remark 1. (Integer; 12,13,21,23,31,32;Default = 13)

SB Allowable inter-laminar shear stress of the bonding material. (Real > 0.0;Default = Failure index not calculated)

NB Allowable inter-laminar normal stress of the bonding material. (Real >0.0; Default = Failure index not calculated)

TREF Reference temperature. (Real; Default = 0.0)

GE Damping coefficient. (Real; Default = 0.0)

GPLYIDi Global ply IDs. For information on stacking order, see Remark 2. (Integer> 0; No default)




Field Contents

MIDi Material ID of the various plies. The MIDs must refer to MAT1, MAT9, orMAT11 bulk entries. For progressive ply failure, the MIDs must refer toMAT11 bulk entries. (Integer > 0; For default behavior, see Remark 3)

TRi Ply thickness. See Remark 4. (Real > 0.0; No default)

THETAi Ply orientation angle. (Real; Default = 0.0)

FTi Ply failure theory. See Remark 5. Allowable entries are:

“HILL” for the Hill failure theory.

“HOFF” for the Hoffman failure theory.

“TSAI” for the Tsai-Wu failure theory.

“STRN” for the Maximum Strain failure theory.

“STRS” for the Maximum Stress failure theory.

“TS” for the Maximum Transverse Shear Stress failure theory.

“PFA” for progressive ply failure. See Remark 6.

(Character; Default = No failure theory)

ILFTi Inter-laminar failure theory. Allowable entries are:

“SB” for transverse shear stress failure index.

“NB” for normal stress failure index.

(Character; Default = No failure index)

SOUTi Controls individual ply stress, strain, and damage output. See Remark 9.Allowable entries are:

“NO” for do not compute.

“YES” for compute.

(Character; Default = “NO”)

REMARKS:1. The software uses the CORDM, PSDIR, and THETAi specifications and the

element coordinate system to define the orientation of the material coordinates.For CHEXA elements, the procedure is as follows:

a. To determine the Zm–axis (the stacking direction), the software uses theabsolute value of direction cosines to determine which element coordinatedirection is most closely aligned with the CORDM axis specified by the secondnumber in the PSDIR field. The most closely aligned element coordinatedirection is used as the Zm–axis.




b. To determine the Xm–axis for the ith ply, the software projects the CORDM axisspecified by the first number in the PSDIR field onto the plane normal to theZm–axis. The software rotates the projected axis about the Zm–axis throughangle THETAi to obtain the Xm–axis for the ith ply. The positive sense ofrotation for THETAi is about the positive Zm–axis.

c. For each ply, the software selects the Ym–axis so that it is orthogonal to theXm–axis for the ply, and the Zm–axis, and yields a right-hand coordinatesystem.

For CPENTA elements, the procedure is as follows:

a. To determine the Zm–axis (the stacking direction), the software selects theelement coordinate direction that is normal to the triangular faces of theelement.

b. To determine the Xm–axis for the ith ply, the software projects the CORDM axisspecified by the first number in the PSDIR field onto the plane normal to theZm–axis. The software rotates the projected axis about the Zm–axis throughangle THETAi to obtain the Xm–axis for the ith ply. The positive sense ofrotation for THETAi is about the positive Zm–axis.

c. For each ply, the software selects the Ym–axis so that it is orthogonal to theXm–axis for the ply, and the Zm–axis, and yields a right-hand coordinatesystem.

The figure shows the material coordinates for the ith ply in a CHEXA and aCPENTA element when PSDIR=32.




2. The ply stacking order is the same as the order of the continuation lines. Theply defined in the first continuation line is ply 1. The ply defined in the secondcontinuation line is ply 2, and so on. Thus, the stacking order is independentof the GPLYIDi values.

Because the orientation of an element coordinate system depends on elementconnectivity, the positive sense for a pair of parallel Zm–axes can differ. To allowfor a single PCOMPS definition to be applied across many elements, the softwareuses the positive sense of the CORDM axis that is used to determine the Zm–axisfor each element as the direction of increasing ply number. That is, ply 2 is furtherout the positive axis than ply 1.

3. MID1 must be defined. If all other MIDi are blank, they default to the value in theMID1 field. If multiple, but not all, MIDi fields are defined, the blank fields default tothe last defined MIDi. For example, if a laminate consists of six plies and MID1and MID4 are defined, MID1 will be used for the first three plies, and MID4 will beused for the last three plies.

4. The laminate thickness is adjusted at the corners to coincide with the distancebetween grid points. The thickness of each ply in the laminate is adjustedproportionally.

5. FTi is failure theory for the ith ply. The material properties for all failure theoriesexcept progressive ply failure are specified by MATFT bulk entries. The materialproperties for progressive ply failure are specified by MATDMG bulk entries. Forthe ith ply, the software references the MATFT or MATDMG bulk entry that has thesame MID as that used for the MIDi field.

6. To considers in-plane progressive damage to a ply, use progressive ply failure.To consider inter-laminar failure, use the SB or NB options in the ILFTi field. Toconsider inter-laminar progressive failure and delamination, leave the ILFTi fieldblank and use cohesive elements to model the inter-laminar behavior.

7. To compute a ply and/or bonding failure index, the STRESS case control commandmust be present, SOUTi on the PCOMPS bulk entry must be set to “YES”, andthe following must be defined.

For a stress or strain ply failure index:

a. FTi on the PCOMPS bulk entry.

b. The stress or strain allowables on the referenced MATFT bulk entry.

For a stress bonding failure index:

a. ILFTi on the PCOMPS bulk entry.

b. The stress allowables SB or NB on the PCOMPS bulk entry.

By default, failure index output prints in the f06 file even when using the PLOT orPUNCH describers on the STRESS and STRAIN case control commands. Theparameter entry PARAM,NOFISR,1 can be used to turn off the printing of thefailure index output. See the parameter NOFISR.




8. Ply stress and strain results are always computed in the ply coordinate system.

9. To request that ply stress and/or strain be computed, the STRESS and/or STRAINcase control command must be defined with the appropriate PRINT, PUNCH,or PLOT output option, and the SOUTi field must equal “YES”. The STRESSand STRAIN commands also include the CPLYMID, CPLYBT, and CPLYBMTdescribers to specify stress or strain recovery at the bottom, middle, or top of theplies. See the remarks on the STRESS and STRAIN case control commands.

10. GPSTRESS or GPSTRAIN output is not supported.

11. Glue or contact definitions defined on composite solid faces which areperpendicular to the stack direction (edge faces) may produce poor stresscontinuity. If the glue/contact definition is between edge faces belonging todifferent PCOMPS definitions, and if the number of plies on each PCOMPSdefinition is small and the same, and the ply thicknesses are similar, the stresscontinuity should be fairly smooth. This also applies to the results requested withthe BCRESULTS and BGRESULTS case control commands.

12. PCOMPS is supported in solutions 101, 103, 105, 108, 109, 111, 112, and 401.

13. For SOLs 101, 103, 105, 108, 109, 111, and 112, the software uses TREF on thePCOMPS entry as the reference temperature for all plies. The software ignoresTREF on the MATi entries referenced by the plies. See the remarks for linearsolutions on the TEMPERATURE case control command for information on howthe reference temperature is used to compute thermal strain in these solutions.

For SOL 401, the software uses TREF defined on the MATi entry referencedby a ply for the ply reference temperature. The software ignores TREF on thePCOMPS entry. See "Thermal Loads" in the Multi-Step Nonlinear User's Guidefor information on how the reference temperature is used to compute thermalstrain in SOL 401.




MATDMG

Material Properties for Progressive Ply Failure

Defines material properties and parameters for progressive ply failure in compositesolid elements. Used in combination with MAT11 entries that have the same MID.Valid for SOL 401 only.

FORMAT:

1 2 3 4 5 6 7 8 9 10MATDMG MID PPFMOD

Y012 YC12 YS12 YS22 Y11LIMT Y11LIMC KSIT KSICB2 B3 A LITK BIGK EXPN TAU ADEL

PLYUNI HBAR DMAX PE

EXAMPLE:

MATDMG 3 UD0.1 12.0 10.0 0.08 5.7 1.0E16 8.00.3 0.5 0.9 20.0 750.0 0.4 0.0001

0.43

FIELDS:

Field Contents


PPFMOD Progressive ply failure model. Allowable entries are:

“UD” for the unidirectional ply model.

(Character; No default)

Y012 Energy threshold for shear damage d12. (Real > 0; For defaultbehavior, see Remark 1)

YC12 Critical value of energy for shear damage d12. (Real > 0; Fordefault behavior, see Remark 1)

YS12 Limit value of energy for shear damage d12. (Real > 0.0; Nodefault)

YS22 Limit energy in the matrix direction. (Real > 0.0; No default)

Y11LIMT Energy threshold in tension for the fiber direction. (Real > 0.0;No default)

Y11LIMC Energy threshold in compression for the fiber direction. (Real> 0.0; No default)

KSIT Nonlinearity coefficient in tension for the fiber direction. SeeRemark 2. (Real; Default = 0.0)




Field Contents

KSIC Nonlinearity coefficient in compression for the fiber direction.See Remark 2. (Real; Default = 0.0)

B2 Coupling coefficient. (Real ≥ 0.0; Default = 0.0)

B3 Coupling coefficient between the damage variables. (Real >0.0; Default = 1.0)

A Coupling coefficient. (Real ≥ 0.0; Default = 0.0)

LITK Initial plastic threshold. (Real > 0.0; Default = 1.0E15)

BIGK Parameter for Plastic Law. (Real ≥ 0.0; Default = 0.0)

EXPN Exponent for Plastic Law. (Real ≥ 0.0; Default = 0.0)

TAU Time constant. See Remark 3. (Real; Default = 0.0)

ADEL Parameter for delay. See Remark 4. (Real > 0.0; Default = 1.0)

PLYUNI Control parameter for the application of nonlinearitycoefficients. (Integer = 0 or 1; Default = 0)

0: Nonlinearity coefficients are applied to stress.

1: Nonlinearity coefficients are applied to strain.

HBAR Transition thickness of ply. (Real ≥ 0.0; Default = 0.0)

DMAX Maximum damage value at a Gauss point. (0.0 < Real ≤0.999; Default = 0.999)

PE 3D effect parameter. (Integer = 0 or 1; Default = 0)

0: Plane stress effect option. The effect of damage in thenormal and shear stress associated with the out-of-planedirection are ignored.

1: 3D stress effect option. The effect of damage in the normaland shear stress associated with the out-of-plane directionare included.

REMARKS:1. An error message is issued if the Y012 and YC12 fields are both blank, or if the

Y012 field or the YC12 field is defined and the other is not.

2. The software uses the nonlinearity coefficients KSIT and KSIC to calculate theelastic modulus in the fiber direction as a nonlinear function of stress if PLYUNI= 0, or strain if PLYUNI = 1.

3. Use a positive value to define time delay. The software interprets negative valuesas zero time delay.




4. If TAU ≤ 0.0, there is no time delay and the ADEL field is ignored.

Element performance enhancementsNX Nastran 11 contains the following element performance enhancements for SOL 401:

• Data structures are optimized for various combinations of geometric and material nonlinearities.The optimized data structures allow the software to exchange data more efficiently. Theperformance improvement is particularly noticeable when only geometric nonlinearities arepresent.

• For composite solid elements:

o The limit of 100 plies in a laminate is removed.

o Laminates with plies that vary in number from element to element are processed moreefficiently.

SOL 401 CaveatsThe following software issues exist in NX Nastran 11.0. They will be fixed in the NX Nastran 11.1maintenance release.

• The RFORCE1 entry applies a rotational load to a portion of a model. The RFORCE1 entryreferences a GROUP entry which lists the grid points where the load is applied.

In SOL 401, if the RFORCE1 entry is selected with the LOAD case control command(time-unassigned loading), and the LVAR parameter on the NLCNTL bulk entry is set to "RAMP"(default), and the GRID entries referenced by the RFORCE1 entry are not ordered sequentially,the incremental loading in the subcase as a result of the RFORCE1 entry will be incorrect.Although, the final subcase loading will be correct.

To avoid the issue, you can either reorder your GRID entries to be sequential, or you can definethe LVAR parameter on the NLCNTL bulk entry to "STEP", or you can select your RFORCE1entry with the DLOAD case control command (time-assigned loading).

For example, if an RFORCE1 entry references a GROUP which lists the grid points 5, 7 and 10:...GROUP,2,++,GRID,5,7,10...GRID,10,..GRID,7,..GRID,5,.....

You can avoid this issue by reordering the GRID entries as follows:

...GRID,5,..GRID,7,..GRID,10,..




• In SOL 401, when multiple bolts are preloaded in a sequence, the output requested with theBOLTRESULTS command will show an incorrect strain value output for all but the last bolt.In addition, when bolts are loaded in a previous subcase and the BOLTRESULTS output isrequested in the current subcase, the strain value for the bolts preloaded in the previoussubcases will be incorrect in the BOLTRESULTS output. Note that all of the bolts are beingpreloaded correctly and the issue is only with the value of the strain output in the f06 and op2 files.

For example, a bolt loaded at 1000N will be loaded correctly with 1000N even though the strainvalue column shows the incorrect value. A query of the axial force values in the BOLTRESULTSoutput will demonstrate the correct bolt force. The strain at which the bolt is being held insubsequent subcases is also correct despite the incorrect strain reported in the BOLTRESULTSoutput. As a result, models with bolts do produce correct behaviour throughout the entire solutionand produce expected results, except for the strain column in the BOLTRESULTS output.



Chapter 6: Advanced nonlinear

Advanced nonlinearDTEMP support for 4D temperature loads

In previously to define time dependent thermal loads, you were required to select temperature loadssimilar to mechanical loads. That is, you would select the temperature loads with the EXCITEIDon the TLOAD1 entry.

Now you can optionally select time dependent thermal loads using the DTEMP case controlcommand. The DTEMP command selects the DTEMP bulk entry, which defines a list of time pointsversus set IDs. The set IDs are the IDs of TEMP or TEMPD entries in the bulk data. This format ofdefining time dependent thermal loads is consistent with SOL 401.

The following input example demonstrates the new time dependent thermal load definition.

...The DTEMP case control command selects the DTEMP bulk entry below.DTEMP = 100...BEGIN BULK...This DTEMP bulk entry includes 3 times and temperature sets.DTEMP 100 ++ 0.0 1 1.0 2 2.0 3...Temperature set 1 is a TEMPD, which in this example,defines a temperature of 0.0 at all grid points.TEMPD,1,0.0...TEMP, 2, 1 , 47.0891TEMP, 2, 2 , 51.6375TEMP, 2, 3 , 55.3994...TEMP, 3, 1 , 59.5615TEMP, 3, 2 , 65.3060TEMP, 3, 3 , 70.0660...

Rotational acceleration static loading

In previous releases, you could use the RFORCE and RFORCE1 bulk entries to define a static loadingas a result of angular velocity, but you could not use the RACC field to define angular acceleration.

Now, the RACC field is supported on the existing RFORCE and RFORCE1 entries.

The RFORCE and RFORCE1 entries have the following comparisons for SOLs 601 and 701:

• The RFORCE1 entry applies static loads to the grid points listed on a referenced GROUP bulkentry as a result of a rotational velocity and rotational acceleration.



• The RFORCE entry applies static loads to all grid points as a result of a rotational velocity androtational acceleration.

Additional output support

The following output options are now supported. The Advanced Nonlinear output format for theserequests is consistent with the other solution types supporting the BCRESULTS, BGRESULTS, andOLOAD commands.

• Contact separation output

The SEPDIS describer on the BCRESULTS case control command is now supported by SOLs601 and 701 to request the final separation distance for grids on edge and surface regions.

• Glue force output

The existing BGRESULTS case control command is now supported to request glue forces inSOL 601.

• Applied load output

The existing OLOAD case control command is now supported by SOLs 601 and 701 to requestthe output of the applied load vector.

See the Advanced Nonlinear Theory and Modeling Guide.



Advanced nonlinear

DTEMP

Time-assigned temperature set selection for SOL 401, 601 and 701.

Selects a time-assigned temperature set to be used for temperature dependentmaterial properties and thermal loading.

FORMAT:DTEMP =n

EXAMPLES:DTEMP=5

DESCRIBERS:

Describer Meaning

n Set identification number of DTEMP or DTEMPEX bulk entries.(Integer > 0)

REMARKS:1. Only supported in static subcases for SOL 401.

2. If both DTEMP and TEMP(LOAD) are specified, the last one defined takesprecedence. For example, if you define the TEMP(LOAD) command globally,and you define the DTEMP command in a subcase, the DTEMP command isused for that subcase.

REMARKSRELATED TO

SOLS 601 AND701:

1. The set identification number must be of a DTEMP bulk entry. The DTEMPEX bulkentry is not supported.

2. DTEMP and TEMP(LOAD) cannot be specified in the same model.


Advanced nonlinear


DTEMP

Time dependent temperature set definition for SOLs 401, 601 and 701.

Defines a time dependent temperature set.FORMAT:

1 2 3 4 5 6 7 8 9 10

DTEMP SID

T1 TID1 T2 TID2 T3 TID3 T4 TID4

T5 TID5 -etc.-

EXAMPLE:

DTEMP 200

0. 1 45. 2 50. 3 60. 4

105. 5 160. 6 170. 7 180.. 8

FIELDS:

Field Contents

SID Unique identification number specified in the DTEMP case controlcommand. (Integer>0)

Ti Times in increasing order of magnitude. (Real ≥ 0.0)

T1 < T2 < T3 <…< Tn

TIDi SID of TEMP or TEMPD bulk entries (Integer>0).

REMARKS:1. SID must be unique to all other DTEMP entries.

2. The SID of the DTEMP bulk entry can only be selected with the DTEMP casecontrol command. The TEMPERATURE case control command cannot be used toselect the DTEMP bulk entry.

3. The same TIDi can be used multiple times on the same DTEMP entry in order todefine the same temperature conditions for multiple times.

4. All TID on a DTEMP entry must have temperatures assigned to the same setof grid points.



Advanced nonlinear

RFORCE

Rotational Force

Defines a static loading condition due to an angular velocity and/or acceleration.

FORMAT:

1 2 3 4 5 6 7 8 9 10RFORCE SID G CID A R1 R2 R3 METHOD

RACC MB

EXAMPLE:

RFORCE 2 5 -6.4 0.0 0.0 1.0 2

1.0

FIELDS:

Field Contents


G Grid point identification number through which the rotation vector acts.(Integer ≥ 0; No default)

CID Coordinate system defining the components of the rotation vector.See Remark 19. (Integer ≥ 0, Default = 0)

A Scale factor of the angular velocity in revolutions per unit time. (Real;No default)

R1, R2, R3Rectangular components of the rotation vector . The vector definedwill pass through point G. (Real; R12 + R22 + R32 > 0.0; Defaults R1= 1.0, R2 = 0.0, R3 = 0.0)

METHOD Method used to compute centrifugal forces due to angular velocity.For angular acceleration, see Remarks 6 and 7. (Integer = 1 or 2;Default = 1)


MB Indicates whether the CID coordinate system is defined in the mainBulk Data Section (MB = –1) or the partitioned superelement Bulk DataSection (MB = 0). Coordinate systems referenced in the main BulkData Section are considered stationary with respect to the assemblybasic coordinate system. See Remark 18. (Integer; Default = 0)

REMARKS:1. In Figure 6-1, the force vector at grid point Gi is given by


Advanced nonlinear



and have the units of revolutions per unit time and revolutionsper unit time squared, respectively. The software multiplies each by 2π to computeω and α:

Angular velocity

Angularacceleration

Note: The equation for will have additional terms if the mass is offset andMETHOD = 1 is selected.

Figure 6-1. RFORCE Vector at Grid Point Gi


3. G = 0 signifies that the rotation vector acts through the origin of the basiccoordinate system.




Advanced nonlinear



No Offset OffsetLumped METHOD = 1 or METHOD

= 2 METHOD = 1

Coupled METHOD = 2 Neither

7. SOL 401 always uses METHOD = 2. As a result, the METHOD field is ignoredby SOL 401.

8. In SOL 401, if a rotational force is defined with the RFORCE or RFORCE1 entry,and spin softening is requested with the SPINK parameter on the NLCNTL entry, ifthe rotation center is defined with a grid point which is not used in the connectivityof any element, all translational DOF for this grid point must be constrained.

9. In SOL 401, loads selected with the LOAD=n case control command are timeunassigned. Time unassigned loads are linearly ramped in a subcase when theLVAR parameter on the NLCNTL entry is set to RAMP (default). The followingrules apply to the time unassigned and ramped RFORCE and RFORCE1 entriesselected in sequentially dependent subcase.

• RFORCE and RFORCE1 entries cannot be defined in the same subcase.

• If multiple RFORCE1 entries are defined in a subcase, the grids associatedwith each RFORCE1 entry must be mutually exclusive.

• The rotational load vector direction defined with the R1, R2, R3 fields and thecoordinate system selected with the CID field cannot change from subcaseto subcase.

• The scale factors A and RACC can change, and RFORCE and RFORCE1entries can be added or removed, as long as the rotational load vectors andcoordinate systems do not change.

10. In cyclic symmetry analyses, the T3 axis of the basic coordinate system must becoincident with the axis of symmetry. In the DIH type of cyclic symmetry, the T1axis also must be parallel to side 1 of segment 1R of the model.



Advanced nonlinear


12. In a geometric nonlinear static analysis (SOL 106 and 401 when PARAM LDGISPis set to +1), this type of loading is a follower force type of loading. However, theorientation of coordinate system CID is not updated.

13. In nonlinear static solutions when there is more than one increment (INC) specifiedon the NLPARM entry for a given subcase, the load vector resulting from theRFORCE input (and not the angular velocity vector) is scaled linearly. This meansthat loading by increments in the angular velocity can only be achieved by havingsubcases where the RFORCE loading is applied in a single increment.




17. The follower force effects due to loads from this entry are included in thestiffness in all linear solution sequences that calculate a differential stiffness. Thesolution sequences are SOLs 103, 105, 107 to 112, 115 and 116 (see also theparameter FOLLOWK). Follower force effects are included in the force balancein the nonlinear static and nonlinear transient dynamic solution sequences,SOLs 106, 129, 153, and 159, if geometric nonlinear effects are turned on withPARAM,LGDISP,1. The follower force stiffness is included in the nonlinear staticsolution sequences (SOLs 106 and 153) but not in the nonlinear transient dynamicsolution sequences (SOLs 129 and 159).

For SOL 401, follower force effects are included in the force balance in thenonlinear static solution if geometric nonlinear effects are turned on withPARAM,LGDISP,1. For additional information, see the NLCNTL bulk entry.


19. If CID is not a rectangular coordinate system, RFORCE will treat it as if it wereand unexpected answers may result.

20. Follower force stiffness (param,followk,yes) is supported for method 2 only.

21. In SOL 401, when RFORCE or RFORCE1 entries are referenced by the EXCITEIDfield on a TLOAD1 entry, the data on the associated TABLEDi, along with the scalefactors S and Si on a DLOAD entry (if defined), scale the angular velocity (ω)and acceleration (α), which are used to compute an inertia force in the equationF = [m] [ω x (ω x r)) + α x r]. Since ω is squared in the force computation,the resulting scaling is not linearly related to the computed force (F). All othersolutions, including SOL 601, scale the computed force (F).



Advanced nonlinear

REMARKSRELATED TO

SOLS 601 AND701:

1. METHOD and MB are ignored.

2. To apply rotational force with constant magnitude, SID is selected by Case Controlcommand LOAD=SID for both static and transient analyses. For magnitudechange due to large deformation, see Remark 4.

3. To apply a time-dependent rotational load, SID is referenced by the field EXCITEID= SID in the TLOAD1 entry. Time-dependent loads are selected by Case Controlcommand DLOAD.

4. By default, in large deformation analysis, the magnitude of the rotational forcechanges due to the deformation. The use of LOADOPT = 0 in NXSTRAT entrycauses the rotational load to be independent of deformation.

5. Only one RFORCE can be applied in an analysis.

6. CID must be a rectangular coordinate system.


Advanced nonlinear


RFORCE1

Rotational Force with repeated SID

Defines a static loading condition due to an angular velocity and/or acceleration.FORMAT:

1 2 3 4 5 6 7 8 9 10

RFORCE1 SID G CID A R1 R2 R3 METHOD

RACC MB GROUPID

EXAMPLE:

RFORCE1 2 5 -6.4 0.0 0.0 1.0 2

1.0

FIELDS:

Field Contents


G Grid point identification number through which the rotation vector acts.(Integer ≥ 0; No default)

CID Coordinate system defining the components of the rotation vector.See Remark 20. (Integer ≥ 0, Default = 0)

A Scale factor of the angular velocity in revolutions per unit time. (Real;No default)

R1, R2, R3Rectangular components of rotation vector . The vector definedwill pass through point G. (Real; R12 + R22 + R32 > 0.0; Defaults R1= 1.0, R2 = 0.0, R3 = 0.0)

METHOD Method used to compute centrifugal forces due to angular velocity.For angular acceleration, see Remarks 7 and 8. (Integer = 1 or 2;Default = 2)


MB Indicates whether the CID coordinate system is defined in the mainBulk Data Section (MB = –1) or the partitioned superelement Bulk DataSection (MB = 0). Coordinate systems referenced in the main BulkData Section are considered stationary with respect to the assemblybasic coordinate system. See Remark 19. (Integer; Default = 0)

GROUPID Group identification number. The GROUP entry referenced in theGROUPID field selects the grid points to which the load is applied.See Remark 23. (Integer > 0)



Advanced nonlinear

REMARKS:1. The RFORCE and RFORCE1 entries have the following difference.

• The RFORCE entry applies loads that result from rotational velocities andaccelerations to all grid points.

• The RFORCE1 entry applies loads that result from rotational velocities andaccelerations to select grid points. The grid points are selected using aGROUP bulk entry.

2. In Figure 6-2, the force vector at a grid point is given by


and have the units of revolutions per unit time and revolutionsper unit time squared, respectively. The software multiplies each by 2π to computeω and α:

Angular velocity

Angularacceleration

Note: The equation for will have additional terms if the mass is offset andMETHOD = 1 is selected.

Figure 6-2. RFORCE1 Vector at a Grid Point


Advanced nonlinear



4. G = 0 signifies that the rotation vector acts through the origin of the basiccoordinate system.




No Offset OffsetLumped METHOD = 1 or METHOD

= 2 METHOD = 1

Coupled METHOD = 2 Neither

8. SOL 401 always uses METHOD = 2. As a result, the METHOD field is ignoredby SOL 401.

9. In SOL 401, if a rotational force is defined with the RFORCE or RFORCE1 entry,and spin softening is requested with the SPINK parameter on the NLCNTL entry, ifthe rotation center is defined with a grid point which is not used in the connectivityof any element, all translational DOF for this grid point must be constrained.

10. In SOL 401, loads selected with the LOAD=n case control command are timeunassigned. Time unassigned loads are linearly ramped in a subcase when theLVAR parameter on the NLCNTL entry is set to RAMP (default). The followingrules apply to the time unassigned and ramped RFORCE and RFORCE1 entriesselected in sequentially dependent subcase.

• RFORCE and RFORCE1 entries cannot be defined in the same subcase.

• If multiple RFORCE1 entries are defined in a subcase, the grids associatedwith each RFORCE1 entry must be mutually exclusive.

• The rotational load vector direction defined with the R1, R2, R3 fields and thecoordinate system selected with the CID field cannot change from subcaseto subcase.



Advanced nonlinear

• The scale factors A and RACC can change, and RFORCE and RFORCE1entries can be added or removed, as long as the rotational load vectors andcoordinate systems do not change.

11. In cyclic symmetry analyses, the T3 axis of the basic coordinate system must becoincident with the axis of symmetry. In the DIH type of cyclic symmetry, the T1axis also must be parallel to side 1 of segment 1R of the model.


13. In a geometric nonlinear static analysis (SOL 106 and 401 when PARAM LDGISPis set to +1), this type of loading is a follower force type of loading. However, theorientation of coordinate system CID is not updated.

14. In nonlinear static solutions when there is more than one increment (INC) specifiedon the NLPARM entry for a given subcase, the load vector resulting from theRFORCE1 input (and not the angular velocity vector) is scaled linearly. Thismeans that loading by increments in the angular velocity can only be achieved byhaving subcases where the RFORCE1 loading is applied in a single increment.




18. The follower force effects due to loads from this entry are included in thestiffness in all linear solution sequences that calculate a differential stiffness. Thesolution sequences are SOLs 103, 105, 107 to 112, 115 and 116 (see also theparameter FOLLOWK). Follower force effects are included in the force balancein the nonlinear static and nonlinear transient dynamic solution sequences,SOLs 106, 129, 153, and 159, if geometric nonlinear effects are turned on withPARAM,LGDISP,1. The follower force stiffness is included in the nonlinear staticsolution sequences (SOLs 106 and 153) but not in the nonlinear transient dynamicsolution sequences (SOLs 129 and 159).

For SOL 401, follower force effects are included in the force balance in thenonlinear static solution if geometric nonlinear effects are turned on withPARAM,LGDISP,1. For additional information, see the NLCNTL bulk entry.



Advanced nonlinear


20. If CID is not a rectangular coordinate system, RFORCE1 will treat it as if it wereand unexpected answers may result.

21. Follower force stiffness (param,followk,yes) is supported for method 2 only.

22. In SOL 401, when RFORCE or RFORCE1 entries are referenced by the EXCITEIDfield on a TLOAD1 entry, the data on the associated TABLEDi, along with the scalefactors S and Si on a DLOAD entry (if defined), scale the angular velocity (ω)and acceleration (α), which are used to compute an inertia force in the equationF = [m] [ω x (ω x r)) + α x r]. Since ω is squared in the force computation,the resulting scaling is not linearly related to the computed force (F). All othersolutions, including SOL 601, scale the computed force (F).

23. Grid points are either listed on the GROUP entry or are related to elements orproperties listed on the GROUP entry as follows:

• If TYPE = “GRID” on the GROUP entry, the GROUP entry lists the grid pointsto which the load is applied.

• If TYPE = “ELEM” on the GROUP entry, the GROUP entry contains a list ofelements. The load is applied to the grid points used in the connectivity of thelisted elements.

• If TYPE = “PROP” on the GROUP entry, the GROUP entry contains a list ofproperties. The load is applied to the grid points used in the connectivity ofelements that reference the listed properties.

REMARKSRELATED TO

SOLS 601 AND701:

1. METHOD and MB are ignored.

2. To apply rotational force with constant magnitude, SID is selected by Case Controlcommand LOAD = SID for both static and transient analyses. For magnitudechange due to large deformation, see Remark 4.

3. To apply a time-dependent rotational load, SID is referenced by the field EXCITEID= SID in the TLOAD1 entry. Time-dependent loads are selected by Case Controlcommand DLOAD.

4. By default, in large deformation analysis, the magnitude of the rotational forcechanges due to the deformation. The use of LOADOPT = 0 in NXSTRAT entrycauses the rotational load to be independent of deformation.

5. CID must be a rectangular coordinate system.

6. Elements which are not selected with your GROUP bulk entry will not contributeto the resulting grid point mass used to compute the load. For example, if a gridpoint is used by elements A and B, but only element A is included in the GROUP,the mass of element A contributes to the grid point mass used to compute theRFORCE1 load. The mass of element B does not contribute. This behavior isunique to solutions 601 and 701. Using the same example, the other NX Nastran



Advanced nonlinear

solutions use the mass contribution of both elements A and B when computing theRFORCE1 load.


Advanced nonlinear


BCRESULTS

Contact Result Output Request (SOLs 101, 103, 111, 112, 401, 601, and 701)

FORMAT:

EXAMPLES:BCRESULTS=ALLBCRESULTS(FORCE,PLOT)=ALLBCRESULTS(TRACTION,FORCE,PLOT)=ALL

DESCRIBERS:

Describer Meaning

TRACTION Contact pressure (scalar) and in-plane contact tractions (vector inbasic coordinate system with units of force per area) are outputfor each contact grid point.

FORCE Contact force vector in basic coordinates is output for eachcontact grid point.

SEPDIS For SOLs 101, 103, 111, and 112, requests the initial and finalseparation distance for grids on the source region.

For SOL 401, requests the final separation distance, and thetotal and incremental slide distance for grids on the source andtarget regions.

See Remark 1.

STATUS Requests the status of contact elements in SOL 401. SeeRemark 3.


PLOT Computes and puts contact results in OP2 file only.


ALL Contact results at all contact grid points will be output.

NONE Contact results will not be output.

n Set identification of a previously appearing SET command. Onlycontact grid points with identification numbers that appear on thisSET command will be output. (Integer>0)

REMARKS :1. For SOLs 101, 103, 111, and 112, the SEPDIS describer requests both the initial

and final separation distance for grids on the source region. The separation



Advanced nonlinear

distance is a scalar quantity representing the source side normal distance to thetarget. During the solution, the separation distance is known at the elementintegration points, but is written to the grids when output. The result at each sourcegrid is the value of separation distance at the closest contact element. If there aretwo or more contact elements equidistant from the grid, then the minimum value ofseparation distance is used at the grids rather than the average, since the averagegives unexpected results for coarse meshes.

For SOL 401, the SEPDIS describer requests the final separation distance forgrids on both the source and target regions. It is computed based on the currentdeformed configuation. For grids on the source region, the separation distance isa scalar quantity representing the source side normal distance to the target. Forgrids on the target region, the separation distance is a scalar quantity representingthe target side normal distance to the source. During the solution, the separationdistance is known at the element integration points, but is written to the gridswhen output. The result at each source and target grid is the value of separationdistance at the closest contact element. If there are two or more contact elementsequidistant from the grid, then the minimum value of separation distance is usedat the grids rather than the average, since the average gives unexpected resultsfor coarse meshes.

In addition for SOL 401, the SEPDIS describer requests the total and incrementalslide or slip distance for grids on both the source and target regions. By default, itrequests slide output. If you set the system cell 642 to 0, the SEPDIS describerrequests the total and incremental slip.

Slide output in SOL 401

SOL 401 computes slide as:

The slide distance is a relative displacement in the tangential direction betweenthe source and target faces. It is computed without regard to the status of thecontact condition. For example, a source and target may not be in contact but theirlocations are changing relative to one another. These changes are included inthe slide distance output. The tangential slide distances are output in the basiccoordinate system. The incremental slide distance is the sliding which occurredsince the last output step. The total slide distance is computed in the currentdeformed configuation and relative to the initial, undeformed configuration. Forexample, if a model is loaded then unloaded in several subcases causing a sourceand target to slide a distance and then return to their initial relative positions, thetotal slide distance in this example is zero.

Slip output in SOL 401

The slip distance computed by SOL 401 is a summation of tangential slippingwhich occurs when the contact condition has the status of "slipping". As a result,slip distance is only computed when a source and target are actually in contact.Slip output is not computed when contact elements have a status of "sticking"or "inactive". The status of "slipping" occurs when the contact frictional force(contact normal force x coefficient of friction) is smaller than the tangential loads.The tangential slip distances are output in the basic coordinate system. The


Advanced nonlinear


incremental slip distance is the slipping which occurred since the last output step.The total slip distance is the summation of the incremental slipping which occurredfrom all previous solution steps from all static subcases. Although, if a contactelement becomes inactive as a result of the source and target separating, theaccumulated total slip is reset back to zero.

2. For edge-to-edge contact, force, traction, and separation distance output can berequested. By default, the contact force for axisymmetric elements is based ona 2π section. The system cell 587 can optionally be set to 1 to select the perradian section basis. The contact force unit is consistent with the applied andreaction force unit for each element.

3. When the STATUS describer is included on the BCRESULTS command in SOL401, an integer value indicating the contact status is output on each grid pointincluded in a contact source or target region. The status values are:

0: No contact exists.

1: A sticking contact condition exist.

2: A sliding contact condition exist.

REMARKSRELATED TO

SOLS 601 AND701:

1. The axisymmetric elements CTRAX3, CQUADX4, CTRAX6, and CQUADX8are always on a per radian basis in solutions 601 and 701. As a result, theedge-to-edge contact force unit for axisymmetric elements is “force/radian”.



Advanced nonlinear

BGRESULTS

Glue Result Output Request (SOLs 101, 103, 105, 401, 601)

FORMAT:

EXAMPLES:BGRESULTS=ALLBGRESULTS(FORCE,PLOT)=ALLBGRESULTS(TRACTION,FORCE,PLOT)=ALL

DESCRIBERS:

Describer Meaning

TRACTION Glue normal traction (scalar) and in-plane glue tractions (vectorin basic coordinate system) are output for each glue grid point.Traction units are force per area.

FORCE Glue force vector is output for each glue grid point.

SEPDIS For SOL 401 only. Requests the final separation distance, andthe total and incremental slide distance for grids on the sourceand target regions.


PLOT Computes and puts glue results in OP2 file only.


SORT1 Output will be presented as a tabular listing of grid points for eachload, frequency, eigenvalue or time, depending of the solutionsequence.

SORT2 Output will be presented as a tabular listing of load,frequency ortime for each grid point (not supported for SOL 401).

ALL Glue results at all contact grid points will be output.

NONE Glue results will not be output.

n Set identification of a previously appearing SET command. Onlyglue grid points with identification numbers that appear on thisSET command will be output. (Integer>0)

REMARKS:1. The glue traction request is supported in solutions 101, 103 (but only for a static

preload subcase if present), 105, and 401 (static subcase only). The glue results


Advanced nonlinear


from SOL 105 are a result of the applied static loads which are not necessarily theloads at which buckling occurs.

2. Sliding glue can be requested in SOL 401 with the parameter setting SLIDE=1on the BGPARM entry. Sliding glue includes a normal stiffness, but no tangentialstiffness. When sliding glue is requested, the SEPDIS describer can be usedto request slide distance output. The slide distance represents the tangentialdistance traveled by the source and target grids relative to each other. The totaland incremental slide distance output is written in the basic coordinate system ongrid points for both the source and target regions. The total slide distance is thevector sum of the incremental slide distances from all time steps. If a subcase issequentially dependent, the total slide distance will also include the total slidedistance from a previous static subcase. Any gaps between the glue edges andsurfaces are preserved as slidiing occurs.

REMARKSRELATED TO

SOLS 601 AND701:

1. Glue traction request is not support in SOL 601.



Advanced nonlinear

OLOAD

Applied Load Output Request

Requests the form and type of applied load vector output.

FORMAT:

EXAMPLES:OLOAD=ALLOLOAD(SORT1,PHASE)=5

DESCRIBERS:

Describer Meaning

SORT1 Output will be presented as a tabular listing of grid points foreach load, frequency, eigenvalue, or time, depending on thesolution sequence.

SORT2 Output will be presented as a tabular listing of frequency ortime for each grid point.


PUNCH The punch file will be the output medium.

REAL or IMAG Requests rectangular format (real and imaginary) of complexoutput. Use of either REAL or IMAG yields the same output.

PHASE Requests polar format (magnitude and phase) of complexoutput. Phase output is in degrees.

PSDF Requests the power spectral density function be calculated forrandom analysis post-processing. The request must be madeabove the subcase level and RANDOM must be selected inthe Case Control. See Remark 11.

ATOC Requests the autocorrelation function be calculated for randomanalysis post-processing. The request must be made abovethe subcase level and RANDOM must be selected in the CaseControl. See Remark 11.


Advanced nonlinear


Describer Meaning

CRMS Requests the cumulative root mean square function becalculated for random analysis post-processing. Request mustbe made above the subcase level and RANDOM must beselected in the Case Control. See Remark 11.

RMS Requests the root mean square and zero crossing functionsbe calculated for random analysis post-processing. Requestmust be made above the subcase level and RANDOM mustbe selected in the Case Control. See Remark 11.

RALL Requests all of PSDF, ATOC, RMS, and CRMS be calculatedfor random analysis post-processing. The request mustbe made above the subcase level and RANDOM must beselected in the Case Control. See Remark 11.

RPRINT Writes random analysis results to the print file. (Default) SeeRemark 11.

NORPRINT Disables the writing of random analysis results to the print file.See Remark 11.

RPUNCH Writes random analysis results to the punch file. See Remark11.

ALL Applied loads for all points will be output. See Remark 2 andRemark 8.

NONE Applied load for no points will be output.

n Set identification of a previously appearing SET command.Only loads on points with identification numbers that appearon this SET command will be output. (Integer>0)


2. The defaults for SORT1 and SORT2 depend on the type of analysis:

• SORT1 is the default in static analysis, frequency response, steady state heattransfer analysis, real and complex eigenvalue analysis, flutter analysis, andbuckling analysis. If SORT2 is selected in a frequency response solution forone or more of the commands ACCE, DISP, FORC, GPFO, MPCF, OLOA,SPCF, STRA, STRE, and VELO then the remaining commands will also beoutput in SORT2 format.

• SORT2 is the default in transient response analysis (structural and heattransfer). SORT2 is not available for real eigenvalue (including buckling),complex eigenvalue, or flutter analysis. If SORT1 is selected in a transientsolution for one or more of the commands ACCE, DISP, ENTH, FORC, GPFO,



Advanced nonlinear

HDOT, MPCF, OLOA, SPCF, STRA, STRE, and VELO then the remainingcommands will also be output in SORT1 format.

• XY plot requests will force SORT2 format thus overriding SORT1 formatrequests.

3. In a statics problem, a request for SORT2 causes loads at all requested points(zero and nonzero) to be output.

4. OLOAD=NONE overrides an overall output request.

5. In the statics superelement solution sequences, and in the dynamics SOLs 107through 112, 118, 145, 146, and 200, OLOADs are available for superelementsand the residual structure. Only externally applied loads are printed, and not loadstransmitted from upstream superelements. Transmitted loads can be obtained withGPFORCE requests.

• In the nonlinear transient analysis solution sequences SOLs 129 and 159,OLOADs are available only for residual structure points and include loadstransmitted by upstream superelements.

6. In nonlinear analysis, OLOAD output will not reflect changes due to follower forces.

7. Loads generated via the SPCD Bulk Data entry do not appear in OLOAD output.

8. In SORT1 format, OLOADs recovered at consecutively numbered scalar pointsare printed in groups of six (sextets) per line of output. But if a scalar point is notconsecutively numbered, then it will begin a new sextet on a new line of output. Ifa sextet can be formed and it is zero, then the line will not be printed. If a sextetcannot be formed, then zero values may be output.

9. OLOAD results are output in the global coordinate system (see field CD on theGRID Bulk Data entry).

10. In inertia relief analysis, the OLOAD output includes both the inertia loads andapplied loads.

11. The following applies to random solutions:

• By default, frequency response results are not output. If in addition to randomoutput, frequency response output is desired, specify SYSTEM(524)=1 orRANFRF=1 in the input file. The PRINT, PUNCH, PLOT describers control thefrequency response output. The RPRINT, NORPRINT, RPUNCH describerscontrol the random output.

• The SORT1 and SORT2 describers only control the output format for thefrequency response output. The output format for random results is controlledusing the RPOSTS1 describer on the RANDOM case control command orthe parameter RPOSTS1, except for RMS results, which are only availablein SORT1 format.


Advanced nonlinear


• Any combination of the PSDF, ATOC, RMS, and CRMS describers can beselected. The RALL describer selects all four.



Chapter 7: GPU Computing

GPU and MIC computingThe graphics processing unit (GPU) and Intel's Many Integrated Core (MIC) are used for applicationsin which computations of large data can be done in parallel. The general approach to performanceis to divide computations across a large number of relatively small cores. Some computationallyintensive portions are offloaded to the GPU or MIC, while the remaining computations still run onthe CPU.

NX Nastran 11 includes the following enhancements for GPU and MIC.

• The NX Nastran MPYAD module performs matrix math operations. You can now enable MIC forMPYAD module operations by defining the intel_mic=1 keyword setting. See MIC capabilitiesbelow.

• You can now enable GPU with DMP for a frequency response solution (FRRD1 module). Forexample, you can define the gpgpu=any keyword to enable the GPU for FRRD1, and definethe dmp=n keyword to specify the number of MPI threads. The maximum number of threads isequal to your number of GPU devices. All of the GPU cards must be identical when enablingDMP. See GPU capabilities below.

• Previously when enabling GPU for FRRD1 module operations, you had to run NX Nastran withthe LP-64 executable.Now, GPU and MIC can be enabled with either the LP-64 and ILP-64 executable for all supportedoperations, including the FRRD1 module.

MIC capabilities

Intel’s Many Integrated Core (MIC) architecture, which is used by the Intel Xeon Phi, is supported forthe following NX Nastran math computations.

• The NX Nastran MPYAD module performs matrix math operations. When enabled, all MPYADcomputations will be done with MIC. For example, a large modal frequency response job (SOL111) using the ddrmm method can benefit when MIC is enabled, particularily when displacementoutput is requested at a large number of grid points.

• NX Nastran supports the Automatic Offload (AO) feature with the MIC-enabled MKL library. NXNastran commonly calls math kernel libraries (MKL) in all solutions. When AO is enabled, andMKL library deems a computation as sufficiently large, it automatically offloads the computation tothe MIC architecture.

You use the intel_mic=1 keyword setting to enable these computations with Intel’s MIC architecture.For example,

nastran.exe intel_mic=1 input_file.dat



GPU capabilities

AMD GPU cards and the NVIDIA GPU cards are supported for NX Nastran frequency response(FRRD1 module) and matrix decomposition (DCMP module) computations.

• Enabling GPU computations for the FRRD1 module speeds up modal frequency responsesolutions (SOL 111) when viscous or structural damping produces coupled damping matrices.The benefit becomes significant when the number of modes is at least 5,000. See the FRRD1with GPU Performance Example below.

• If you have multiple GPUs, you can optionally enable GPU and DMP together for the FRRD1module. See the FRRD1 with GPU and DMP Performance Example below.

• Enabling GPU computations for the DCMP module decreases the time for matrix decomposition.The impact is more significant for sparse matrices reporting a maximum front size larger than30K in the .f04 file.

You can use the gpgpu=any keyword setting to enable the GPU for both FRRD1 and DCMP modulecomputations. For example,

nastran.exe gpgpu=any input_file.dat

To enable GPU with DMP for a frequency response solution (FRRD1 module), you should enablethe GPU with a keyword setting such as gpgpu=any, and define the number of MPI threads withthe dmp=n keyword up to your number of GPU devices. All of the GPU cards must be identicalwhen enabling DMP.

Keyword Input Summary

Enabling Intel’s MIC architecture:

intel_micintel_mic=1 Enables Intel’s MIC architecture for MPYAD module and MKL

computations.

Enabling GPU for both FRRD1 and DCMP module computations:

gpgpugpgpu=none Disables GPU for both FRRD1 and DCMP module computations.

gpgpu=any Enables GPU for both FRRD1 and DCMP module computations withthe first available AMD or NVIDIA GPU.

gpgpu=amd Enables GPU for both FRRD1 and DCMP module computations withthe first available AMD GPU.

gpgpu and dmpkeywords Enables GPU with DMP for the FRRD1 module computations.

Enabling GPU for FRRD1 module computations only:

cl_frrd

cl_frrd=1 Enables GPU for FRRD1 module computations with the first availableAMD or NVIDIA GPU.

cl_frrd=2 Enables GPU for FRRD1 module computations with the first availableAMD GPU.



GPU Computing

cl_frrd=3 Enables GPU for FRRD1 module computations with the first availableNVIDIA GPU.

Enabling GPU for DCMP module computations only.

cl_dcmp

cl_dcmp=1 Enables GPU for DCMP module computations with the first availableAMD or NVIDIA GPU.

cl_dcmp=2 Enables GPU for DCMP module computations with the first availableAMD GPU.

cl_dcmp=1sys531=1

Enables GPU for DCMP module computations with the first availableNVIDIA GPU. (Both cl_dcmp=1 and sys531=1 are required for thisoption)

Intel MIC Example

You use the intel_mic keyword to enable MKL computations with Intel’s MIC architecture. Forexample,

nastran.exe intel_mic=1 input_file.dat

If an automatic offload occurs, you should see the following in your log file:

14:33:18 Application of Loads and Boundary Conditions started.14:33:21 Application of Loads and Boundary Conditions completed.[MKL] [MIC --] [AO Function] DGEMM[MKL] [MIC --] [AO DGEMM Workdivision] 0.00 1.00[MKL] [MIC 00] [AO DGEMM CPU Time] 0.816250 seconds[MKL] [MIC 00] [AO DGEMM MIC Time] 0.094590 seconds[MKL] [MIC 00] [AO DGEMM CPU->MIC Data] 9397248 bytes[MKL] [MIC 00] [AO DGEMM MIC->CPU Data] 24443904 bytes

Note: No messages are printed if Intel MIC was requested but not used.

Modal frequency response (FRRD1 module) Example

You can use the gpgpu or the cl_frrd keyword to enable the GPU for both FRRD1 modulecomputations. For example,

nastran.exe cl_frrd=1 input_file.dat

The FRRD1 module reports the following in the f04 file:

16:42:31 1:31 13595.0 ... FREQRS 256 FRRD1 BEGN*** USER INFORMATION MESSAGE 4157 (FRDGPU)

PARAMETERS FOR FRDGPU FOLLOWMATRIX SIZE = 7628 NUMBER OF FREQUENCIES = 64SYSTEM (107) = 32768 SYSTEM (573) = 1

Module DMAP Matrix Cols Rows F T NzWds Density BlockT StrL NbrStr BndAvgFRRD1 256 SCR 308 320 7628 2 4 30512 1.00000D+00 152 5204 469 7628FRRD1 256 UHF 320 7628 2 4 30512 1.00000D+00 152 5204 469 762816:53:32 12:32 15161.0 1566.0 417.1 326.9 FREQRS 256 FRRD1 END

FRRD1 with GPU performance example

This example uses AMD Tahiti GPU (4GB), 24 core Magny-Cours.


GPU Computing


The damping definition in the model produced coupled damping matrices.

Modes were computed up to the given frequency, where e10k = 1785 modes, e20k = 3631 modes,e30k = 5576 modes, and e40k = 7646 modes. GPU memory was exhausted around 10,000 modes.



GPU Computing

FRRD1 with GPU and DMP performance example

This example uses two AMD Tahiti GPU (4GB).

The damping definition in the model produced coupled damping matrices.

Modes were computed up to the given frequency, where e10k = 1785 modes, e20k = 3631 modes,e30k = 5576 modes, e40k = 7646 modes, e50k = 9787 modes and e60k = 12088 modes.


GPU Computing

Chapter 8: RDMODES improvements

RDMODES automatic NREC computationRDMODES is based on substructuring technology and requires the number of external partitions(NREC) to be specified with the keyword NREC.

In NX Nastran 11, you can now define NREC=1 and the software will automatically compute areasonable number of partitions based on your model size. The resulting number of partitions willbe reported in the .f06 file.

If you define NREC>1, the software will use the specified value as the number of partitions, as inprevious NX Nastran releases.

RDMODES restart improvementRecursive Domain Normal Modes (RDMODES) is a parallel capability that uses substructuringtechnology for large scale normal modes analysis. Solution restarts together with RDMODES havebeen enhanced to make the following workflows more efficient.

• SOL 111 example workflow

1. You run a modal frequency response solution (SOL 111) to compute the frequency responseat a few key grid locations for all frequencies of interest. You plot the resulting frequencyresponse function (FRF) to determine the frequencies in which the response is critical.

2. You then rerun the same solution one or more times to, for example, compute the responsefor all DOF, but only at the critical frequencies. The response computed for all grid points issometimes called the Operational Deformed Shape (ODS).

• SOL 103 example workflow

1. You run a normal modes solution (SOL 103) to compute a large number of modes butrequest minimal or perhaps no output.

2. You then rerun the same solution one or more times to, for example, request output forspecific modes.

In previous releases, for both of these workflows, you could use RDMODES, and you could userestart procedures to reuse the already computed modes in a restart solution. If the model size andthe number of modes were extremely large, the amount of restart data would also be extremely large.The reuse of extremely large restart data can be inefficient.

In NX Nastran 11, a new RDMODES restart method is available which reduces the amount ofeigenvector restart data. When the new parameter setting PARAM,ODS,YES is included in the bulkdata for the first run, and you run with RDMODES, the eigenvector result is stored in terms of thereduced, RDMODES substructure representation. As a result, the size of the restart data is much



smaller. In addition, the restart data is organized for an RDMODES restart solution to begin veryefficiently.

New RDMODES restart method

1. The first RDMODES solution step computes and stores sparse eigenvectors, along with specialoutput datablocks which are used for output data recovery in the second solution step.

- Your solution should be either SOL 103 or SOL 111.

- You should include the command line keywords to request RDMODES. You can run RDMODESas DMP or as SMP. For example, a DMP run could be requested with dmp=2 nrec=2.

- You should include PARAM,ODS,YES in the bulk data section to turn on ODS.

- You should include the command line keyword scratch=no to save the solution restart data atthe end of this first solution.

2. The second RDMODES solution step is a restart solution.

- Your solution sequence must be the same as the one used in step one (SOL 103 or SOL 111).

- Since this is a restart run, you will remove all of the bulk data from your input file, includingthe ODS parameter definition used in step one. In addition, an assign statement and a restartstatement should be included in the file management section of your input file. For example,for a serial run:

assign run1='test_ods.MASTER' $restart logical=run1 $

The same example for a DMP run (note the wild card t*):

assign run1='test_ods.t*.MASTER' $restart logical=run1 $

- You should include the command line keywords to request RDMODES. You must run the sameRDMODES option, SMP or DMP, that you ran in step one.

- You can modify the case control section to change, for example, output requests, solutionfrequencies with the FREQi commands for SOL 111, or mode numbers with the MODSELcommand.

- You do not need to save your restart data in this run, so the command line keyword scratch=yescan be included.

Additional RDMODES information:

You activate RDMODES by entering the Nastran keyword ‘nrec’ on the command line. To specifythe desired parallel functionality, you can also enter the Nastran keywords ‘dmp’ or ‘smp’. Samplecommand line entries include:

DMP: NASTRAN nrec = m dmp = p

Serial: NASTRAN nrec = m

SMP: NASTRAN nrec = m smp = p



RDMODES improvements

where m is the number of external partitions and p is the number of processors.

See the Parallel Processing Guide for information on all parallel options.


RDMODES improvements

Chapter 9: Optimization

Optimization enhancementsAuto-generated shell thickness design variablesIn previous versions of NX Nastran, associating design variables with the thickness of one shellelement in SOL 200 required at least one DESVAR entry, and a DVPREL1 entry for each element.If the thicknesses of many shell elements were expected to change independently of others, as intopometry optimization, you were required to specify DESVAR, DVPREL1, and PSHELL bulk entriesfor each element that could change.

To alleviate this need, in NX Nastran 11, an option for the software to automatically create theseentries is available. Use the new DVEREL1 bulk entry to make the request. The GRPID field on theDVEREL1 entry selects the ID of a GROUP bulk entry, and the GROUP entry selects the elementsthat are to participate in topometry optimization. The shell elements CTRIA3, CTRIA6, CTRIAR,CQUAD4, CQUAD8, and CQUADR are supported.

The GROUP entry referenced by the DVEREL1 entry must currently use TYPEi=ELEM. The softwareignores any unsupported elements in the ELEM lists, and it ignores elements selected on a GROUPentry with TYPEi=PROP.

For each element selected by the DVEREL1 and associated GROUP entries, the softwareautomatically associates a new design variable with the element thickness. This results in a separateindependent thickness design variable for each element selected. The starting thickness value isdetermined as follows:

• If the shell element definition in the input file includes corner thicknesses, the software computesan average thickness for the element.

• If corner thicknesses are not defined, the thickness on the original PSHELL in the input file is used.

As the solution searches for an optimum, each of these element thicknesses can vary independently.If you request a punch file output, the resulting element thicknesses are written as corner thicknessesin the connectivity data.

The design variable to property relation created by the DVEREL1 bulk entry has the form

P = COEF * DV

where DV is the design variable value, P is the element thickness, and COEF is defined on theDVEREL1 entry.

The DVEREL1 entry also includes the PMIN and PMAX fields to limit the thickness value. The valuesof COEF, PMIN, and PMAX apply to all design variables created as a result of a single DVEREL1entry definition. You can define multiple DVEREL1 entries if you require different PMIN, PMAX, COEFvalues on different shell regions, or to simply organize the input for different regions.

By default, the ID numbers of the auto-generated DESVAR entries are the same as their associatedelement ID numbers. Alternatively, you can define a starting ID value in the DVID1 field. Each new IDfor the same DVEREL1 is then incremented by one.



Note that the ID of each auto-generated DESVAR entry must be unique with respect to any existingDESVAR or other DVEREL1 generated DESVAR. These IDs cannot duplicate any existing DVPREL1or PSHELL IDs either. Therefore, care should be taken when defining the DVID1 field on theDVEREL1 entry.

If you request an .op2 file with the PARAM,POST,-1 or PARAM,POST-2 definitions, the final shellcorner thicknesses are written to the OSHT1 datablock in the .op2 file at the end of the analysis. Thethickness values written to the .op2 file represent the best design obtained during optimization. Youcan optionally display the thickness values in a post processor which supports the OSHT1 datablock.

In addition, the new EDVOUT parameter is available on the DOPTPRM bulk entry to control whatfraction of DVEREL1 generated design variables are printed. The printing of variables occurs inthe Design Variable History at the end of the .f06 file, as well as at requested cycles. The fractionyou assign the EDVOUT parameter is applied separately to the increased and to the decreasedDVEREL1 generated design variables. For example, when the default of 0.001 is used, both 0.1%of the most increased and 0.1% of the most decreased DVEREL1 generated design variables areprinted. A value of 1.0 requests to print all DVEREL1 generated design variables which have eitherincreased or decreased. Note that the design variables which are not generated by the DVEREL1entry are all printed in full.

SDO Enhancements

The optimizer choices for SOL 200 are DOT (default) and Siemens Design Optimization (SDO). Youcan select SDO by setting the NASTRAN system cell 425 to 1.

NASTRAN SYSTEM(425) = 1

SDO has been considerably enhanced to improve the quality of the results. On the average, it canhandle larger problems than DOT, especially in regard to large scale topometry optimization usingthe new bulk entry DVEREL1. You are encouraged to try SDO.



Optimization

DVEREL1

Automatic shell element thickness design variable

Automatic shell element thickness design variable.FORMAT:

1 2 3 4 5 6 7 8 9 10

DVEREL1 ID TYPE GRPID PNAME PMIN PMAX

DVID1 COEF1

EXAMPLE:

DVEREL1 701 PSHELL 1001 T 0.1 10.0

4053 0.1

The referenced GROUP bulk entry may look like the following.

...GROUP, 1001, shell_thickness,+

+, ELEM, 1001, THRU, 1871+, ELEM, 2001, THRU, 2589...

FIELDS:

Field Contents

ID Unique identification number. (Integer>0)

TYPE The property type used by the elements selected on the associatedGROUP entry. The software will auto-generate design variables forthese elements. Currently only PSHELL is supported. This field is casesensitive. (Character; Default=PSHELL)

GRPID ID of a GROUP bulk entry which selects the shell elements CQUADR,CQUAD4, CQUAD8, CTRIAR, CTRIA3, CTRIA6 for which the softwarewill auto-generate a design variable associated with the thickness. Seethe remarks and the example. (Integer>0)

PNAME Property name or field position of the property entry. Currently, only "T"is supported. (Character or Integer; Default=T)

PMIN Minimum value allowed for the associated properties. (Real;Default=1.0E-15)

PMAX Maximum value allowed for the associated properties. (Real; Default=1.0E+20)

DVID Identification number for the first auto-generated PSHELL, DESVAR,and DVPREL1 entry. When the default is used, the design variableIDs will be the same as the IDs of the associated shell elements.(Integer>0; Default=0)


Optimization


Field Contents

COEF The coefficient in the expression P = COEF*DV. (Real; Default =1)

REMARKS:1. The GROUP entry referenced by the DVEREL1 entry must currently use

TYPEi=ELEM. The software ignores any unsupported elements in the ELEM lists,and it ignores elements selected on a GROUP entry with TYPEi=PROP.

2. For each element selected by the DVEREL1 and associated GROUP entries,the software automatically associates a new design variable with the elementthickness. This results in a separate independent thickness design variable foreach element selected. The starting thickness value is determined as follows:

- If the shell element definition in the input file includes corner thicknesses, thesoftware will compute an average thickness for the element.

- If corner thicknesses are not defined, the thickness on the original PSHELLin the input file is used.

3. The relationship between the connectivity property and design variables is givenby:

4. A GROUP ID may only be referenced by a single DVEREL1.

5. The ID of each auto-generated DESVAR entry must be unique with respect toany existing DESVAR or other DVEREL1 generated DESVAR. These IDs cannotduplicate any existing DVPREL1 or PSHELL IDs either. Therefore, care should betaken when defining the DVID1 field on the DVEREL1 entry.

6. If you request an .op2 file with the PARAM,POST,-1 or PARAM,POST-2 definitions,the final shell corner thicknesses are written to the OSHT1 datablock in the.op2 file at the end of the analysis. The thickness values written to the .op2 filerepresent the best design obtained during optimization. You can optionally displaythe thickness values in a post processor which supports the OSHT1 datablock.

7. The EDVOUT parameter is available on the DOPTPRM bulk entry to controlwhat fraction of DVEREL1 generated design variables are printed. The printingof variables occurs in the Design Variable History at the end of the f06 file, aswell as at requested cycles. The fraction you assign the EDVOUT parameter isapplied separately to the increased and to the decreased DVEREL1 generateddesign variables. For example, when the default of 0.001 is used, both 0.1% ofthe most increased and 0.1% of the most decreased DVEREL1 generated designvariables will be printed. A value of 1.0 requests to print all DVEREL1 generateddesign variables which have either increased or decreased.

To determine the most increased and the most decreased thickness variables, thesoftware evaluates the variables using their percentage change between the bestand initial design cycles. For example, if the thickness of variable one decreases



Optimization

from 1.0 to 0.8 or 20%, and the thickness of variable two decreases from 3.0 to2.55 or 15%, variable one will have priority for printing.

Note that the design variables which are not generated by the DVEREL1 entry areall printed in full.


Optimization


DOPTPRM

Design Optimization Parameters

Overrides default values of parameters used in design optimization.

FORMAT:

1 2 3 4 5 6 7 8 9 10

DOPTPRM PARAM1 VAL1 PARAM2 VAL2 PARAM3 VAL3 PARAM4 VAL4

PARAM5 VAL5 -etc.-

EXAMPLE:

DOPTPRM IPRINT 5 DESMAX 10

FIELDS:

Field Contents

PARAMi Name of the design optimization parameter. Allowable names aregiven in Table 9-1. (Character)

VALi Value of the parameter. (Real or Integer) See Table 9-1.

REMARKS:1. Only one DOPTPRM entry is allowed in the Bulk Data Section.

Table 9-1. PARAMi Names and Descriptions

Name Description , Type, and Default Value

APRCOD

Approximation method to be used. 1 = Direct Linearization;2=Mixed Method based on response type; 3 = ConvexLinearization. APRCOD = 1 is recommended for shapeoptimization problems. (Integer 1, 2, or 3; Default = 2)

CONV1Relative criterion to detect convergence. If the relative change inobjective between two optimization cycles is less than CONV1,then optimization is terminated. (Real>0.0; Default = 0.0001)

CONV2Absolute criterion to detect convergence. If the absolute changein objective between two optimization cycles is less than CONV2,then optimization is terminated. (Real>0.0; Default = 1.0E-20)

CONVDV Relative convergence criterion on design variables. (Real>0.0;Default = 0.001)

CONVPR Relative convergence criterion on properties. (Real>0.0; Default= 0.001)



Optimization



CT Constraint tolerance. Constraint is considered active if currentvalue is greater than CT. (Real<0.0; Default = -0.03)

CTMIN Constraint is considered violated if current value is greater thanCTMIN.(Real>0.0; Default = 0.003)

DABOBJ*Maximum absolute change in objective between ITRMOPconsecutive iterations (see ITRMOP) to indicate convergenceat optimizer level. F0 is the initial objective function value. SeeRemark 2. (Real>0.0; Default = MAX[0.001*ABS(F0), 0.0001])

DELB Relative finite difference move parameter. (Real>0.0; Default= 0.0001)

DELOBJ*Maximum relative change in objective between ITRMOPconsecutive iterations to indicate convergence at optimizer level.See Remark 2. (Real>0.0; Default = 0.001)

DELPFractional change allowed in each property during anyoptimization design cycle. This provides constraints on propertymoves. (Real>0.0; Default = 0.2)

DELXFractional change allowed in each design variable during anyoptimization cycle. (Real>0.0; Default = 1.0) See DXMIN forabsolute minimum change allowed per cycle for design variables.

DESMAX Maximum number of design cycles (not including FSD cycle) tobe performed. (Integer ≥ 0; Default = 5)While the default for DESMAX is 5 cycles, large problems oftenrequire a significantly higher number of cycles. For example,this could be somewhere between 20 and 50, depending onmany factors. The most significant factors are the time requiredfor a full analysis pass, the number of design variables, and thenonlinearity of the constraints.

DISBEG Design cycle ID for discrete variable processing initiation.Discrete variable processing analysis is carried out for everydesign cycle after DISBEG. (Integer>=0, default = 0=the lastdesign cycle) If fully stressed design (FSD), then discretevariable processing can start only after the last FSD cycle.


Optimization




DISCOD Discrete Processing Method: (Integer 1, 2, 3 or 4; Default = 1)

1: Design of Experiments

2: Conservative Discrete Design

3: Rounding up to the nearest design variable

4: Rounded off to the nearest design variable

DOBJ1* Relative change in objective attempted on the first optimizationiteration. Used to estimate initial move in the one-dimensionalsearch. Updated as the optimization progresses. See Remark2. (Real>0.0; Default = 0.1)

DOBJ2* Absolute change in objective attempted on the first optimizationiteration. See Remark 2. (Real>0.0; Default = 0.2*(F0))

DPMIN Minimum move limit imposed. (Real>0.0; Default = 0.01)

DX1* Maximum relative change in a design variable attempted onthe first optimization iteration. Used to estimate the initial movein the one dimensional search. Updated as the optimizationprogresses. See Remark 2. (Real>0.0; Default = 0.01)

DX2* Absolute change in a design variable attempted on the firstoptimization iteration. See Remark 2. (Real>0.0; Default =0.2*MAX[X(I)])

DXMIN Minimum absolute limit on design variable move (Real>0.0;Default = 0.05). See DELX for allowable relative change percycle in design variables.

EDVOUT Defines what fraction of DVEREL1 generated design variableswith increased and decreased values are to be printed into theDesign Variable History at the end of the f06 file, as well asat requested cycles. This fraction is applied separately to theincreased and to the decreased DVEREL1 generated designvariables. For example, when the default of 0.001 is used, both0.1% of the most increased and 0.1% of the most decreasedDVEREL1 generated design variables will be printed. A value of1.0 requests to print all DVEREL1 generated design variableswhich have either increased or decreased. (0.0<Real≤1.0;Default = 0.001)

Note: The increase or decrease in the value of a DVEREL1generated design variable is based on the relative changebetween the “initial” and the “best design” cycles.



Optimization



Note: The design variables which are not generated by theDVEREL1 entry are all printed in full.

FSDALP Relaxation parameter applied in Fully Stressed Design (Real,0.0<FSDALP ≤ 1.0, Default = 0.9)

FSDMAX Specifies the number of Fully Stressed Design Cycles that are tobe performed (Integer, Default = 0)

GMAX Maximum constraint violation allowed at the converged optimum.(Real>0.0; Default = 0.005)

GSCAL Constraint normalization factor. See Remarks under theDSCREEN and DCONSTR entries. (Real>0.0; Default = 0.001)

IGMAX If IGMAX = 0, only gradients of active and violated constraintsare calculated. If IGMAX>0, up to NCOLA gradients arecalculated including active, violated, and near active constraints.(Integer≥0; Default = 0)

IPRINT* Print control during approximate optimization phase.

Increasing values represent increasing levels of optimizerinformation. See Remark 2. (0 ≤ Integer ≤ 7; Default = 0)

0 no output (Default)

1 internal optimization parameters, initial information, and results

2 same as 1, plus objective function and design variables ateach iterations

3 same as 2, plus constraint values and identification of criticalconstraints

4 same as 3, plus gradients

5 same as 4, plus search direction

6 same as 5, plus scaling factors and miscellaneous searchinformation

7 same as 6, plus one dimensional search information

IPRNT1* If IPRNT1 = 1, print scaling factors for design variable vector.See Remark 2. (Integer 0 or 1; Default = 0)


Optimization




IPRNT2* If IPRNT2 = 1, print miscellaneous search information. If IPRNT2= 2, turn on print during one-dimensional search process.(Warning: This may lead to excessive output.) See Remark 2.(Integer 0, 1, or 2; Default = 0)

ISCAL Design variables are rescaled every ISCAL iterations. SetISCAL = -1 to turn off scaling. (Integer; Default=NDV (number ofdesign variables))

ITMAX* Maximum number of iterations allowed at optimizer level duringeach design cycle. See Remark 2. (Integer; Default = 40)

ITRMOP* Number of consecutive iterations for which convergence criteriamust be satisfied to indicate convergence at the optimizer level.See Remark 2. (Integer; Default = 2)

ITRMST* Number of consecutive iterations for which convergence criteriamust be met at the optimizer level to indicate convergence inthe Sequential Linear Programming Method. See Remark 2.(Integer>0; Default = 2)

IWRITE* FORTRAN unit for print during approximate optimization phase.Default value for IWRITE is set to the FORTRAN unit forstandard output. See Remark 2. (Integer>0, Default=6 or valueof SYSTEM(2).)

JPRINT* Sequential Linear Programming subproblem print. If JPRINT>0,IPRINT is turned on during the approximate linear subproblem.See Remark 2. (Default = 0)

JTMAX* Maximum number of iterations allowed at the optimizer level forthe Sequential Linear Programming Method. This is the numberof linearized subproblems solved. See Remark 2. (Integer≥0;Default = 20)

JWRITE* If JWRITE>0, file number on which iteration history will bewritten. See Remark 2. (Integer>0; Default = 0)



Optimization



METHOD DOT Optimization Method: (Integer 1, 2, or 3; Default = 1)

1: Modified Method of Feasible Directions. (Default)

2: Sequential Linear Programming

3: Sequential Quadratic Programming

For Siemens Analytic Design System (SADS), all selections willautomatically revert to a proprietary, linear programming basedalgorithm. To request the SADS optimizer, system cell 425 inTable 1-1 of the NASTRAN Statement section should be set to 1.

P1 Determines the design cycles in which output is printed. (Integer≥ 0; Default = 0)Initial results are always printed prior to the first approximateoptimization. If an optimization task is performed, finalresults are always printed for the final analysis unlessPARAM,SOFTEXIT,YES is specified. These two sets of print arenot controllable.n: Print at every n-th design cycle.

P2 Items to be printed at the design cycles defined by P1 (Integer;Default = 1)0: No print.1: Print objective and design variables. (Default)2: Print properties.4: Print constraints.8: Print responses.16: Print weight as a function of a material ID (note that thisis not a design quantity so that only inputs to the approximatedesign are available).n: Sum of desired items. For example, P2 = 10 means printproperties and responses.

P2RSET ID of a SET1 bulk entry listing constrained responses tobe printed if retained (the SET1 lists DRESPi ID numbers).The default is to print all retained constrained responses.Constrained responses are those responses referenced directlyor indirectly by a DCONSTR bulk entry. Retained constrainedresponses are the constrained responses which the softwaredetermines to be relevant in a design cycle in terms of beingcritical in driving the optimization process.


Optimization




PLVIOL Flag for handling of property limit violation. By default, the jobwill terminate with a user fatal message if the property derivedfrom design model (DVPRELi, DVMRELi, DVCRELi) exceedsthe property limits. Setting PLVIOL to a non-zero number willcause the program to issue a user warning message by ignoringthe property limits violation and proceed with the analysis.(Integer; Default=0)

PTOL Maximum tolerance on differences allowed between theproperty values on property entries and the property valuescalculated from the design variable values on the DESVAR entry(through DVPRELi relations). PTOL is provided to trap ill-poseddesign models. (The minimum tolerance may be specifiedon user parameter DPEPS. See “Parameters and ParameterApplicability Tables” ) (Real>0.0; Default = 1.0E+35)

STPSCL Scaling factor for shape finite difference step sizes, to be appliedto all shape design variables. (Real>0.0; Default = 1.0)

2. The parameter names with “*” are supported only by the DOT Optimization Method.



Chapter 10: Topology Optimization

NX Nastran Topology OptimizationA new NX Nastran Topology Optimization product is available for solutions 101 and 103. It isindependent of SOL 200 and has its own inputs and license requirement. The capability works withina single overall objective, for example, minimizing mass, along with one or a number of constraints,for example, limiting displacements at specific grids.

You can optionally use the Simcenter product to define an NX Nastran Topology Optimizationsolution and to post-process the results. See NX Nastran Topology Optimization in Simcenter forthese instructions.

The following optimization scenarios are supported.

Solution 101 Linear Statics

• Mass objective and displacement constraints.

• Mass objective and compliance constraint.

• Compliance objective and mass constraint.

• Displacement objective and mass constraint.

Solution 103 Normal Modes

• Mass objective and eigenvalue constraints.

• Eigenvalue objective and mass constraints.

The elements selected for the optimization, and their initial fill value are the design variables. Thefill value is how the software indicates the amount of element material remaining. A fill value of 1.0indicates that all element material is present, and a value of 0.0001 indicates that all material isremoved. The elements available as design variables are

• 1D elements: CROD(10), CONROD(1), CBAR(34), CBEAM(2)

• 2D elements: CTRIA3(74), CTRIA6(75), CQUAD4(33), CQUAD8(64)

• 3D elements: the 4 and 10 grid CTETRA(39), the 8 and 20 grid CHEXA(67), and the 6 and15 grid CPENTA(68).

NX Nastran outputs the final, optimized fill values into the normalized material density (ELRSCALV)output data block for post processing.

Design Variable Inputs

• The design variables are entered using the direct matrix input (DMI) format.



The header line for the DMI entry has the format:

DMI,EFILL,0,2,1,2,,3,n

where n is the number of design variables.

The subsequent lines have the format:

DMI,EFILL,CID,1,ETYPE,ELID,f_i

where

o CID is the design variable number starting with “1”.

o “1” is required in the fourth column.

o ETYPE is the element type. For example, the CQUAD4 has an element code of “33”. It mustbe defined with a decimal since the software expects a real value for this DMI field.

o ELID is the element ID and must be defined with a decimal since the software expects areal value for this DMI field.

o f_i is the initial fill value, which is typically set to “1.0”.

For example, the following DMI input defines two design variables for two CQUAD4 elementswith IDs 6 and 7. The initial fill value is set to “1.0” for both.

DMI,EFILL,0,2,1,2,,3,2DMI,EFILL,1,1,33.,6.,1.00DMI,EFILL,2,1,33.,7.,1.00

Objective and Constraint Inputs

• The single objective and the contraints are entered using the direct table input (DTI) format.

The header line for the DTI entry has the format:

DTI,OBJT,0,T1

where T1 is the sum of 1 (the single objective) + number of constraints.

The subsequent lines have the format:

DTI,OBJT,CID,OTYPE,OCID,OCOPT,ENDREC

where:

o CID is the number assigned to the objectives and constraints, starting with “1”.

o OTYPE is the objective/constraint type, and is set to the following:

■ MASS to minimize or maximize mass.

■ EVAL to minimize or maximize a particular eigenvalue.

■ DISP to minimize or maximize a displacement.

■ COMP to minimize or maximize a compliance.



Topology Optimization

o OCID has the following values:

■ When OTYPE=MASS, OCID = 0 for off, or OCID = 1 for on.

■ When OTYPE=DISP, OCID is the ID of a grid point.

■ When OTYPE=COMP and you are using a gravity load, you should define OCID = -1.

When OTYPE=COMP and you are using any other forces or moments, you shoulddefine OCID = 0.

■ When OTYPE=EVAL, OCID is an eigenvalue number.

o OCOPT has the following meanings:

■ For an objective, OCOPT should be set to +/- 1.0

◊ OCOPT = -1.0 if the objective is to maximize.

◊ OCOPT = 1.0 if the objective is to minimize.

■ For a constraint, OCOPT should not be set to +/- 1.0.

◊ OCOPT > 0.0 defines a upper constraint bound. For example, 1.1 defines an upperconstraint at 110% of the initial value.

◊ OCOPT < 0.0 defines a lower constraint bound. For example, -0.9 defines a lowerconstraints at 90%.

Other DTI examples:

• The entry “DTI,OBJT,k,MASS,1,1.0” simply requests mass minimization.

• The entry “DTI,OBJT,k,EVAL,i,1.5” places a constraint on the i-th eigenfrequency not to exceedthe upper constraint of 150% of the initial value.

• The entry “DTI,OBJT,k,DISP,j,-0.2” places a constraint on the j-th grid for its displacement not todeviate from the initial value by more than 20% below.

• The entry “DTI,OBJT,k,DISP,j,1.5” places a constraint on the j-th grid for its displacement not toexceed the upper constraint of 150% of the initial value.

• The following DTI input defines an objective to minimize mass, and a constraint change no morethan above 110% of the initial value at the 5th grid point.

DTI,OBJT,0,2DTI,OBJT,1,MASS,1,1.0,ENDREC

DTI,OBJT,2,DISP,5,1.1,ENDREC

• The following DTI input defines an objective to minimize mass, and a constraint change nomore than below 80% of the initial compliance.

DTI,OBJT,0,2DTI,OBJT,1,MASS,1,1.0,ENDRECDTI,OBJT,2,COMP,0,-0.8,ENDREC




• The following DTI input defines an objective to minimize mass, and a constraint change no morethan above 120% of the initial compliance with gravity load.

DTI,OBJT,0,2DTI,OBJT,1,MASS,1,1.0,ENDRECDTI,OBJT,2,COMP,-1,1.2,ENDREC

• The following DTI input defines an objective to maximize eigenvalue, and a Mass constraintchange between 45% and 50% of the initial mass

DTI,OBJT,0,3DTI,OBJT,1,EVAL,1,-1.0,ENDRECDTI,OBJT,2,MASS,1,-0.45,ENDRECDTI,OBJT,3,MASS,1,0.5,ENDREC

Additional input requirements

• You must define the ESE case control command. Failure to do so will cause a fatal solutionerror. At a minimum, the strain energy request can be for the set elements included as designvariables, or you can simply request output for all elements. In addition, the THRESH describeron the ESE command must be set to 0.0.

• For a SOL 103 topology optimization, you must define the EKE case control command. Failure todo so will cause a fatal solution error. At a minimum, the strain energy request can be for theset elements included as design variables, or you can simply request output for all elements. Inaddition, the THRESH describer on the ESE command must be set to 0.0.

• You must define the DISPLACEMENT and GPFORCE case control commands for the grid pointswhich are referenced in a displacement constraint. Requesting this output for all grid points, forexample DISPLACEMENT=ALL and GPFORCE=ALL, is also acceptable. Failure to request thisoutput will cause a fatal solution error. These output requests must be defined globally (abovethe subcase level) if multiple subcases exist.

• A force must be applied at all grid points in which an optimization displacement constraint orobjective is defined. The force direction is not important. The exact force magnitude is notcritical, but it should be of a similar order to your actual applied loads to prevent any numerical orconvergence problems. Failure to apply these forces will cause a fatal solution error. If subcasesexist, the loads must be defined in the same subcases as the corresponding constraints orobjectives.

• All design elements must have the same density defined on their respective MATi entries.

Parameter Inputs

Parameters Descriptions




PARAM,ITOPOPT,2 or 3

Required to select the mathematical optimizer. The GCMoptimizer (PARAM,ITOPOPT,2) is generally more robustand recommended.=2 (default) Selects the GCM mathematical optimizer.=3 Selects the CONLIN mathematical optimizer.

PARAM,ITODENS,valueOptionally defines the material density of the designelements. When the default setting is used (default=1.0),the density defined on the MATi entries is used.

PARAM,GRDPNT,0 Required to compute mass.

PARAM,ITOMXITR Optionally selects the maximum number of iterations(Default=10).

PARAM,ITOSIMP

Optionally used to specify a stiffness penalty factor. A valueof 2.0 or 3.0 is recommended. Increasing the stiffnesspenalty factor helps to bias the separation of the fill valuestoward either 0 or 1. (Default=1.0).

PARAM,ITOSIMP1 and ITOSIMP2

ITOSIMP1 and ITOSIMP2 must be used together.

ITOSIMP1 specifies a lower fill-in threshold above which thepenalty factor ITOSIMP2 is applied.

These values are important in an eigenvalue optimization.The recommended settings in an eigenvalue optimizationare ITOSIMP1=0.1 and ITOSIMP2=100.0.

When a compliance objective is created for a gravityload, the recommended settings are ITOSIMP1=0.25 andITOSIMP2=16.0.

PARAM,ITORMAS Optionally used to specify the residual mass of the structurenot participating in optimization (Default=0.0).

PARAM,ITONGHBR,1

PARAM,ITONGHBR,1 can help to eliminate thecheckerboard phenomenon when small and large fill valuesare interspersed. The option considers the neighbors ofeach element, and does a weighting of the fill values.(Default= 0)

PARAM,ITOPDIAG

Controls the level of diagnostics and internal statistics insidethe optimization. (Default=-1).

=-1 Minimum diagnostics.

= 0 Medium diagnostics.

=1 Maximum diagnostics.

PARAM,BAILOUT PARAM,BAILOUT,-1 is required to continue withintermediate unstable solutions

Example parameter inputs:

BEGIN BULK...PARAM,ITOPOPT,2PARAM,ITODENS,2.588e-4PARAM,GRDPNT,0PARAM,ITOMXITR,20




...

Example Input File

SOL 101CENDMETHOD=1SET 1 = 5,35ESE(PLOT,AVERAGE,THRES=0.0) = ALLDISPLACEMENT = ALLGPFORCE = 1LOAD = 1BEGIN BULKFORCE,1,5,,1.0E5,0.0,0.0,-1.0PARAM,POST,-2PARAM,GRDPNT,0PARAM,ITOPOPT,2PARAM,ITOMXITR,20PARAM,ITODENS,2.588e-4GRID,1,,0.,0.,0.,,123456GRID,2,,1.,0.,0.GRID,3,,2.,0.,0.GRID,4,,3.,0.,0.GRID,5,,4.,0.,0.GRID,11,,0.,1.,0.,,123456GRID,12,,1.,1.,0.GRID,13,,2.,1.,0.GRID,14,,3.,1.,0.GRID,15,,4.,1.,0.GRID,21,,0.,2.,0.,,123456GRID,22,,1.,2.,0.GRID,23,,2.,2.,0.GRID,24,,3.,2.,0.GRID,25,,4.,2.,0.GRID,31,,0.,3.,0.,,123456GRID,32,,1.,3.,0.GRID,33,,2.,3.,0.GRID,34,,3.,3.,0.GRID,35,,4.,3.,0.MAT1 1001 11.538+6.3 2.588-4 1.E-6 0.PSHELL 101 1001 1.0 1001CQUAD4,1,101,1,2,12,11CQUAD4,2,101,2,3,13,12CQUAD4,3,101,3,4,14,13CQUAD4,4,101,4,5,15,14CQUAD4,5,101,11,12,22,21CQUAD4,6,101,12,13,23,22CQUAD4,7,101,13,14,24,23CQUAD4,8,101,14,15,25,24CQUAD4,15,101,21,22,32,31CQUAD4,16,101,22,23,33,32CQUAD4,17,101,23,24,34,33CQUAD4,18,101,24,25,35,34$ Design variable matrixdmi,efill,0,2,1,2,,3,2dmi,efill,1,1,33.,6.,1.00




dmi,efill,2,1,33.,7.,1.00$ Design objective tabledti,objt,0,2dti,objt,1,MASS,1,1.0,ENDRECdti,objt,2,DISP,5,1.1,ENDRECenddata



Chapter 11: Miscellaneous

LP-64 and ILP-64 executablesFinal release for LP-64 executable

Two 64-bit executable types have been provided since the ILP-64 type was first introduced in NXNastran 4:

• LP-64 is the original 64-bit executable. You can allocate up to 8 GB of RAM with this executable.

• ILP-64 is the executable first introduced in NX Nastran 4. Practically speaking, you can allocateas much RAM as your machine supports with this executable.

NX Nastran 11 is the last release for the LP-64 executable. Only the ILP-64 executable will beavailable in NX Nastran 12. Please contact your Siemens account representative if you have anyconcerns.

New default for nastran.exe

In NX Nastran 10, when you ran an NX Nastran job with either the nastran.exe or nastranw.execommands in the /bin directory, the LP-64 executable would be used.

In NX Nastran 11, the nastran.exe and nastranw.exe commands now run the ILP-64 executable.

If you prefer to run the LP-64 executable for NX Nastran 11, you can use the nastran64.exe ornastran64w.exe executables.

Convert 64-bit XDB file to 32-bitThe CONVERT_TO_XDB_32 utility is now available to convert a binary results database file (XDB)produced by the ILP-64 version of NX Nastran into a binary results database file compatible with thatproduced by the LP-64 version of NX Nastran.

The utility is available in the NX Nastran 11 installation hierarchy at the following locations.

On Windows:

nxn11/em64tntL/convert_to_xdb_32.bat

On Linux:

nxn11/x86_64linuxl/convert_to_xdb_32

The basic format of the “convert_to_xdb_32” command is

convert_to_xdb_32 binary_xdb_file

where binary_xdb_file is the name of the XDB file produced by the ILP-64 executable.



An XDB file cannot be read from stdin. If the file extension of the XDB file is “.xdb”, you can optionallyomit “.xdb” from the command line. The name of the LP-64 XDB file will be the same as the originalname, with an _32 appended. That is, the filename.xdb becomes filename ._32.xdb. A directorypath may be include with the filename.

The following is an example Shell Script that converts some existing XDB files to 32-bit while runningthe ILP-64 executable.

#!/bin/csh -f#setenv NXN_BASE /Siemens/NXN11#setenv NXN_VERSD nxn11#setenv NXN_ARCH x86_64linuxl#foreach file ( dbx102 dbx201 dbx302

dbx402 dbx511 dbx605 dbx702 dbx801 dbx902 )#$NXN_BASE/bin/nastran $file \

out=./out/$file\

prt=no scr=yesbat=no not=no diag=8,15 system20=0 \

post="$NXN_BASE/$NXN_VERSD/$NXN_ARCH/convert_to_xdb_32 ./out/$file"#end

Support for MAT11 with axisymmetric elements and 2D solid elementsBeginning with NX Nastran 11, as a recommended practice, use MAT11 bulk entries to defineorthotropic material properties for axisymmetric elements and 2D solid elements. Axisymmetricelements include CCHOCKi, CTRAX3, CQUADX4, CTRAX6, and CQUADX8 elements. 2D solidelements include CPLSTNi and CPLSTSi elements.

In earlier versions of NX Nastran, you use MAT3 bulk entries to define orthotropic material propertiesfor CPLSTNi, CPLSTSi, CTRAX3, CQUADX4, CTRAX6, and CQUADX8 elements. However, MAT3bulk entries are not supported for use with the chocking elements that are being introduced in NXNastran 11.

To support the use of the MAT11 bulk entry to define orthotropic material properties in axisymmetricelements and 2D solid elements, the following documentation changes are made to the MAT11bulk entry:

• The 1–, 2–, and 3–directions on the MAT11 bulk entry are now described as principal materialdirections rather than as longitudinal, lateral, and layup directions, respectively. This is done toemphasize that the 1–direction need not be the direction that has the maximum elastic modulus.

• A remark that describes how the 1–, 2–, and 3–directions on the MAT11 bulk entry map to theXm–, Ym–, and Zm–directions of the axisymmetric and 2D solid elements is now included.



Miscellaneous

Similar documentation changes are made to the MAT3 bulk entry.

Note

The MAT3 bulk entry is scheduled to be undocumented in the next version of NX Nastran.

For more information, see the updated MAT3 and MAT11 bulk entries.


Miscellaneous


MAT3

Orthotropic Material Property Definition for Axisymmetric, Plane Stress and PlaneStrain Elements

Defines linear orthotropic materials for the axisymmetric elements CQUADX4,CQUADX8, CTRAX3, CTRAX6; the plane strain elements CPLSTN3, CPLSTN4,CPLSTN6, CPLSTN8; and the plane stress elements CPLSTS3, CPLSTS4, CPLSTS6,CPLSTS8.

Note

Except for axisymmetric models in SOL 601, 701, the use of MAT11 isrecommended for defining orthotropic materials for axisymmetric elementsand 2D solid elements.

FORMAT:

1 2 3 4 5 6 7 8 9 10MAT3 MID EX EY EZ NUXY NUYZ NUZX RHO

GXY GZX AX AY AZ TREF GE

EXAMPLE:

MAT3 23 1.0+7 1.1+7 1.2+7 .3 .25 .27 1.0-5

2.5+6 1.0-4 1.0-4 1.1-4 68.5 .23

FIELDS:

Field Contents


EX, EY, EZ Young’s moduli in the X-, Y-, and Z-principal materialdirections. (Real > 0.0)

NUXY, NUYZ, NUZX Poisson’s ratios: (Real)

NUXY = Poisson’s ratio for strain in the Y-principal materialdirection when stressed in the X-principal material direction.NUYZ = Poisson’s ratio for strain in the Z-principal materialdirection when stressed in the Y-principal material direction.NUZX = Poisson’s ratio for strain in the X-principal materialdirection when stressed in the Z-principal material direction.

RHO Mass density. (Real)

GZX Shear modulus when elements are defined on the XZ-planeof the basic coordinate system. (Real > 0.0)

GXY Shear modulus when elements are defined on the XY-planeof the basic coordinate system. (Real > 0.0)



Miscellaneous

Field Contents

AX, AY, AZ Thermal expansion coefficients in the X-, Y-, and Z-principalmaterial directions. (Real)

TREF Reference temperature for the calculation of thermal loadsor a temperature-dependent thermal expansion coefficient.See Remark 6. (Real or blank)

GE Structural element damping coefficient. See Remarks 7 and8. (Real)

REMARKS:1. The material identification number must be unique with respect to the collection of

all MAT1, MAT2, MAT3, MAT8, MAT9, and MAT11 entries.

2. MAT3 materials may be made temperature dependent by use of the MATT3 entry.In SOL 106, linear and nonlinear elastic material properties in the residual structurewill be updated as prescribed under the TEMPERATURE case control command.

3. Note the following:

See Understanding the MAT3 Bulk Entry in the NX Nastran User’s Guide for theMAT3 strain-stress relations for the axisymmetric, plane stress, and plane strainelements.

4. A warning message will be issued if any value of NUXY or NUYZ has an absolutevalue greater than 1.0.

5. For CPLSTNi, CPLSTSi, CQUAX4, CQUADX8, CTRAX3, and CTRAX6 elements,the X,Y,Z–principal material directions on the MAT3 bulk entry correspond to theXm,Ym,Zm–directions on the elements, respectively.

6. TREF is used for two different purposes:

• In nonlinear static analysis (SOL 106), TREF is used only for the calculationof a temperature-dependent thermal expansion coefficient. The referencetemperature for the calculation of thermal loads is obtained from theTEMPERATURE(INITIAL) set selection. See the remarks on the MAT1 bulkentry.

• In all SOLs except 106, TREF is used only as the reference temperature forthe calculation of thermal loads. TEMPERATURE(INITIAL) may be used forthis purpose, but TREF must be blank.

7. To obtain the damping coefficient GE, multiply the critical damping ratio C/Co by2.0.


Miscellaneous


8. If PARAM,W4 is not specified, GE is ignored in a transient analysis.

REMARKSRELATED TO

SOL 601:1. GE is ignored.

2. TREF is used only when MAT3 is made temperature dependent by use of theMATT3 entry.



Miscellaneous

MAT11

Solid Element Orthotropic Material Property Definition

Defines the orthotropic material properties for axisymmetric elements, 2D solidelements, 3D solid elements, and 3D solid composite elements.

FORMAT:

1 2 3 4 5 6 7 8 9 10MAT11 MID E1 E2 E3 NU12 NU13 NU23 G12

G13 G23 RHO A1 A2 A3 TREF GE

EXAMPLE:

MAT11 101 2.1E7 2.2E7 2.3E7 0.31 0.29 0.33 2.1E6

2.2E6 2.3E6 0.34 0.35 0.36 0.37 0.38 0.39

FIELDS:

Field Contents


E1 Modulus of elasticity in the 1–principal material direction. See Remark1. (Real > 0.0; No default, must be defined)



NU12 Poisson’s ratio (ε2 / ε1 for uniaxial loading in 1-principal materialdirection). (Real > 0.0; No default, must be defined)



G12 Shear modulus relating τ12 and γ12. (Real > 0.0; No default, mustbe defined)



RHO Mass density. (Real or blank; Default = 0.0)


Miscellaneous


Field Contents

A1 Thermal expansion coefficient in 1–principal material direction. (Realor blank; Default = 0.0)



TREF Reference temperature for the calculation of thermal loads, or atemperature-dependent thermal expansion coefficient. (Real or blank;Default = 0.0)

GE Structural damping coefficient. (Real or blank; Default = 0.0)

REMARKS:1. For CCHOCKi, CHEXA, CPENTA, CPLSTNi, CPLSTSi, CPYRAM, CQUAX4,

CQUADX8, CTETRA, CTRAX3, and CTRAX6 elements, the 1,2,3–principalmaterial directions on the MAT11 bulk entry correspond to the Xm,Ym,Zm–directionson the elements, respectively.

2. In general, NUij is not equal to NUji, but they are related as follows:

NUij / Ei = NUji / Ej

3. Material stability requires that the following relations are satisfied:

Ei > NUij2 Ej

and

1-NU12 NU21 – NU23 NU32 – NU31 NU13 – 2 NU21 NU32 NU13 > 0.0

4. MAT11 materials may be made temperature dependent by use of the MATT11entry.

5. MAT11 entries cannot be used as design variables in SOL 200 (via the DVMREL1and DVMREL2 bulk entries).

REMARKSRELATED TO

SOLS 601 AND701:

1. GE is ignored.

2. TREF is used only when MAT11 is made temperature dependent by use of theMATT11 entry.

Element geometry checksFor NX Nastran 11, the following changes have been made to the element geometry checks:



Miscellaneous

• User-controlled element geometry checks are supported for the new cohesive elements CHEXCZand CPENTCZ, and the new chocking elements CCHOCK3, CCHOCK4, CCHOCK6, andCCHOCK8.

• The edge-point-included-angle (EPIA) user-controlled element geometry check is available as aseparate check. It is no longer a part of the edge-point-length-ratio (EPLR) user-controlledelement geometry check.

The EPIA check is valid for the solid elements CHEXA, CPENTA, CPYRAM, and CTETRA, andthe cohesive elements CHEXCZ and CPENTCZ.

• For CQUAD8 and CTRIA6 elements, system cell 635 is available for you to change the maximumallowable angle between normals to corner grids for the EPLR check.

For more information, see the updated GEOMCHECK executive control statement.


Miscellaneous


GEOMCHECK

Specifies Geometry Check Options

Specifies tolerance values for (optional) finite element geometry tests.FORMAT:

DESCRIBERS:

Describer Meaning

test_keyword A keyword associated with the particular element geometry test.See Remark 2 for a list of acceptable selections.

tol_value Tolerance value to be used for the specified test. See Remark 2for default values of the test tolerances.

n The maximum number of messages that will be produced. Thedefault is 100 messages for each element type. See Remark 3.

FATAL Geometry tests that exceed tolerance values produce fatalmessages. See Remark 4.

INFORM Geometry tests that exceed tolerance values produceinformative messages. See Remark 4.

WARN Geometry tests that exceed tolerance values produce warningmessages. See Remark 4.

SUMMARY A summary table of the geometry tests performed is produced.No individual element information messages are output.

NONE None of the optional element geometry tests will be performed.

EXAMPLES:1. Adjust the tolerance for the CQUAD4 element skew angle test to 15.0 degrees

and limit messages to 50.

GEOMCHECK Q4_SKEW=15.0,MSGLIMIT=50

2. Limit messages to 500 for each element type.

GEOMCHECK MSGLIMIT=500

3. Adjust the tolerance for the CQUAD4 element taper and set the message type tofatal for all tests.

GEOMCHECK Q4_TAPER=0.4,MSGTYPE=FATAL



Miscellaneous

4. Request summary table output only using default tolerance values.GEOMCHECK SUMMARY

REMARKS:1. There are two categories of element checks in an NX Nastran solution:

• The system controlled checks will always occur. As the name implies, thereis no user control to these checks. The system controlled checks will alwaysproduce a fatal error if a condition is found which prevents the analysis toproceed.

See “System Element Checks” in the NX Nastran User’s Guide for descriptionsof these checks.

• GEOMCHECK are the optional, user controlled checks, and can optionallygenerate a fatal error if it finds an element which fails the user defined criteria.By default, GEOMCHECK does not produce fatal errors. Element checkswhich are controlled with the GEOMCHECK statement are summarizedin Remark 2. See “User Controlled Element Checks” in the NX NastranUser’s Guide for detailed descriptions of all checks. The GEOMCHECKelement checks will occur using default values when the GEOMCHECKstatement is not included. GEOMCHECK controls are available for the shellelements CQUAD4, CQUADR, CTRIA3, CTRIAR, the solid elements CHEXA,CPENTA, CPYRAM, CTETRA, CHEXCZ, CPENTCZ the axisymmetricelements CTRAX3, CTRAX6, CQUADX4, CQUADX8, the plane stresselements CPLSTS3, CPLSTS4, CPLSTS6, CPLSTS8, the plane strainelements CPLSTN3, CPLSTN4, CPLSTN6, CPLSTN8, the chocking elementsCCHOCK3, CCHOCK4, CCHOCK6, CCHOCK8, the CBAR element, andthe CBEAM element. Multiple GEOMCHECK directives may be present.Continuations are acceptable.

Note

Be aware that when MSGTYPE=inform, GEOMCHECK mayflag a poor quality element with an informational message, theelement may pass the system check, and the solve may complete.MSGTYPE should be set appropriately if you expect fatal errorsin these cases. Fatal errors can also be forced by assigning anegative value to MSGLIMIT, for example, MSGLIMIT=-100. Thisis also useful since a specific “FAIL” message will be reported foreach element failing the GEOMCHECK criteria. See Remark 3 formore information on MSGLIMIT.

2. The test_keyword describer can optionally be used to modify the defaultthresholds. The following table lists the test_keywords and their defaults. Thetest_keyword inputs are Real ≥ 0.0. See “User Controlled Element Checks” in theNX Nastran User’s Guide for detailed descriptions of all element checks.

test_keyword Default Threshold SummaryCQUAD4 and CQUADR Shell Element Checks


Miscellaneous


test_keyword Default Threshold SummaryQ4_SKEW Failure when < 30.0 Skew angle in degreesQ4_TAPER Failure when > 0.5 Taper ratioQ4_WARP Failure when > 0.05 Surface warping factorQ4_IAMIN Failure when < 30.0 Minimum Interior Angle in degreesQ4_IAMAX Failure when > 150.0 Maximum Interior Angle in degreesQAD_AR Failure when > 100.0 Longest edge to shortest edge aspect

ratio (CQUAD4)CTRIA3 and CTRIAR Shell Element Checks

T3_SKEW Failure when < 10.0 Skew angle in degreesT3_IAMAX Failure when > 160.0 Maximum Interior Angle in degrees

CQUAD8 Shell Element ChecksQ8_SKEW Failure when < 30.0 Skew angle in degreesQ8_TAPER Failure when > 0.5 Taper ratioQ8_IAMIN Failure when < 30.0 Minimum Interior Angle in degreesQ8_IAMAX Failure when > 150.0 Maximum Interior Angle in degreesQ8_AR Failure when > 100.0 Longest edge to shortest edge aspect

ratioQ8_EPLR Failure when < 0.5 Edge point length ratio

CTRIA6 Shell Element ChecksTA6_IAMN Failure when < 10.0 Minimum Interior Angle in degreesTA6_IAMX Failure when > 160.0 Maximum Interior Angle in degreesTA6_AR Failure when > 100.0 Longest edge to shortest edge aspect

ratioTA6_EPLR Failure when < 0.5 Edge point length ratio

CTETRA Solid Element ChecksTET_AR Failure when >100.0 Longest edge to shortest height aspect

ratioTET_EPIA Failure when > 30.0 Edge point included angleTET_EPLR Failure when < 0.5 Edge point length ratio

CHEXA Solid Element ChecksHEX_AR Failure when > 100.0 Longest edge to shortest edge aspect

ratioHEX_EPIA Failure when > 30.0 Edge point included angleHEX_EPLR Failure when < 0.5 Edge point length ratio

HEX_TK Failure when > 0.05

Ratio of the difference between thicknessin stacking direction as defined bygrids and as defined by ply thicknessspecification to the thickness in thestacking direction as defined by gridsfor CHEXA elements that referencePCOMPS entries only



Miscellaneous

test_keyword Default Threshold Summary

HEX_TP Failure when > 1.2Ratio of longest edge to shortest edge instacking direction for CHEXA elementsthat reference PCOMPS entries only

HEX_WARP Failure when < 0.707 Face warp coefficientCPYRAM Solid Element Checks

PYR_AR Failure when > 100.0 Longest edge to shortest edge aspectratio

PYR_EPIA Failure when > 30.0 Edge point included anglePYR_EPLR Failure when < 0.5 Edge point length ratioPYR_WARP Failure when < 0.707 Face warp coefficient

CPENTA Solid Element ChecksPEN_AR Failure when > 100.0 Longest edge to shortest edge aspect

ratioPEN_EPIA Failure when > 30.0 Edge point included anglePEN_EPLR Failure when < 0.5 Edge point length ratio

PEN_TK Failure when > 0.05

Ratio of the difference between thicknessin stacking direction as defined bygrids and as defined by ply thicknessspecification to the thickness in thestacking direction as defined by gridsfor CPENTA elements that referencePCOMPS entries only

PEN_TP Failure when > 1.2Ratio of longest edge to shortest edge instacking direction for CPENTA elementsthat reference PCOMPS entries only

PEN_WARP Failure when < 0.707 Quadrilateral face warp coefficientCHEXCZ Solid Element Checks

HEX_AR Failure when > 100.0 Longest edge to shortest edge aspectratio

HEX_EPIA Failure when > 30.0 Edge point included angleHEX_EPLR Failure when < 0.5 Edge point length ratioHEX_WARP Failure when < 0.707 Face warp coefficientCPENTCZ Solid Element Checks

PEN_AR Failure when > 100.0 Longest edge to shortest edge aspectratio

PEN_EPIA Failure when > 30.0 Edge point included anglePEN_EPLR Failure when < 0.5 Edge point length ratioPEN_WARP Failure when < 0.707 Face warp coefficientChecks for the Axisymmetric Elements CTRAX3 and CTRAX6, the PlaneStress Elements CPLSTS3 and CPLSTS6, the Plane Strain Elements

CPLSTN3 and CPLSTN6, the Chocking Elements CCHOCK3 and CCHOCK6TRX_IAMN Failure when < 30.0 Minimum Interior Angle in degreesTRX_IAMX Failure when > 160.0 Maximum Interior Angle in degrees


Miscellaneous


test_keyword Default Threshold SummaryTRX_AR Failure when > 100.0 Longest edge to shortest edge aspect

ratio

TRX_EPLR Failure when < 0.5 Edge point length ratio (CTRAX6,CPLSTS6, CPLSTN6, CCHOCK6)

Checks for the Axisymmetric Elements CQUADX4 and CQUADX8, thePlane Stress Elements CPLSTS4 and CPLSTS8, the Plane Strain ElementsCPLSTN4 and CPLSTN8, the Chocking Elements CCHOCK4 and CCHOCK8QDX_IAMN Failure when < 30.0 Minimum Interior Angle in degreesQDX_IAMX Failure when > 150.0 Maximum Interior Angle in degreesQDX_AR Failure when > 100.0 Longest edge to shortest edge aspect

ratioQDX_SKEW Failure when < 30.0 Skew angle in degreesQDX_TAPR Failure when > 0.5 Taper ratio

QDX_EPLR Failure when < 0.5 Edge point length ratio (CQUADX8,CPLSTS8, CPLSTN8, CCHOCK8)

CBEAM and CBAR Element ChecksBEAM_OFF Failure when > 0.15 CBEAM element offset length ratioBAR_OFF Failure when > 0.15 CBAR element offset length ratio

3. A single line summarizing the results of all tests for an element will be output ifany of the geometry tests exceeds the test tolerance. Only the first n of thesemessages will be produced. A summary of the test results indicating the number oftolerances exceeded as well as the element producing the worst violation is alsooutput. If the SUMMARY keyword has been specified, only the summary table isproduced and none of the single line element messages will be output.

Solutions which fail with numerical problems, i.e. negative Jacobian, reportdifferently based on the sign of MSGLIMIT. When troubleshooting a failed analysis,you may find it useful to switch between the following two strategies:

Value ofMSGLIMIT Meaning when numerical fatal errors occur

> 0 (positive)

If numerical problems are found resulting from poor qualityelements, a FATAL ERROR message is generated withoutthe offending element ID, the analysis terminates, but theGEOMCHECK criteria is processed and output for all elements.

This strategy works when only a few elements fail theGEOMCHECK. However, if there are hundreds or thousands offailures, diagnosing the critical elements could become difficult.In addition, the offending element ID may or may not have failedthe GEOMCHECK criteria depending on the criteria you entered.



Miscellaneous

< 0 (negative)

If numerical problems are found resulting from poor qualityelements, a FATAL ERROR message is generated whichincludes the offending element ID, the analysis terminates, yetGEOMCHECK is not processed for all elements. The downsideof using a negative MSGLIMIT is if the model contains multipleoffending elements, the procedure of fixing/rerunning needs to berepeated until all offending elements have been corrected.

4. When SUMMARY is not specified, each geometry test that exceeds the tolerancewill be identified in the single line output summary by an indicator based on thespecification for MSGTYPE. For the FATAL option, the indicator is “FAIL”; for theINFORM option, it is “xxxx”; for the WARN option, it is “WARN”. If the FATALoption is specified and any test fails, the run is terminated.

NX Nastran value-based licensingNX Nastran 11 supports a value-based licensing model, which allows you to purchase tokens that youcan use to access some NX Nastran products.

With value-based licensing, tokens are generic and can be used to check out licenses of any NXNastran or other Simcenter 3D capability that is supported in the value-based licensing program.This provides you with significant flexibility in accessing the breadth of CAE capabilities offeredby Simcenter 3D.

Value-based licensing operates using the same license server used for standard licenses. Whenthe server receives a request for an NX Nastran license, it first attempts to check out a standardlicense. If the license is not available and the capability is covered by value-based licensing, theserver requests the checkout of a defined amount of tokens. If the number of tokens is available,the server checks them out. They are unavailable for other uses until the NX Nastran job is finishedand the server checks them back in.

When you attempt to use a product for which you do not have enough tokens, a license errormessage appears in the NX Nastran .log file.

Contact your account administrator for more information and to purchase tokens.

NX Nastran products that support value-based licensingNX Nastran BasicNX Nastran Advanced AcousticsNX Nastran Dynamic ResponseNX Nastran DMPNX Nastran AeroNX Nastran SuperelementNX Nastran DMAP


Miscellaneous

Chapter 12: Documentation changes

Removing documentation for legacy axisymmetric elementsBeginning with NX Nastran 11, the CQUADX, CTRIAX, CTRIAX6, CCONEAX, CAXIFi, CFLUIDi,CSLOT3, and CSLOT4 axisymmetric elements are removed from the documentation. In addition, anycase control command or bulk entry that is used exclusively with these elements is also removedfrom the documentation.

The following table lists all of the case control commands and bulk entries that are removed from thedocumentation:

AXIC CSLOT3 GRIDB PRESPTAXIF CSLOT4 GRIDF RINGAXAXSLOT CTRIAX GRIDS RINGFLAXISYMMETRIC(1) CTRIAX6 MOMAX SECTAXBDYLIST DMIAX MPCAX SLBDYCAXIFi FLSYM OMITAX SPCAXCCONEAX FORCEAX PCONEAX SUPAXCFLUIDi FREEPT POINTAX TEMPAXCQUADX FSLIST PRESAX(1) Denotes case control command.

Although you can still use the case control command and bulk entries for which the documentationhas been removed, as a best practice, in an axisymmetric analysis use the CQUADX4, CQUADX8,CTRAX3, and CTRAX6 elements. These elements were introduced in NX Nastran 6. They possessall the capabilities of the legacy axisymmetric elements plus the following capabilities:

• They are supported for use in SOL 401.

• They are all supported for heat transfer analysis.

• They can be used where the axisymmetric plane is either the XY plane or XZ plane of thebasic coordinate system.

Removing documentation for axisymmetric acoustic cavity modelingBeginning with NX Nastran 11, the information related to Axisymmetric Acoustic Cavity Modeling,which was in the NX Nastran User's Guide, has been removed from the documentation.



Removing documentation for p-elementsThe following case control commands, parameters, and bulk entries that are used exclusively withp-elements are removed from the documentation.

ADACT GMINTC PSET VUPENTA(2)ADAPT(1) GMINTS PVAL VUQUAD4(2)ADAPT OUTPUT PVALINIT(2) VUTETRA(2)ALTSHAPE(2) OUTRCV(1) SDRPOPT(2) VUTRIA3(2)DATAREC(1) OUTRCV TEMPF VUELJUMP(2)GMBNDC PEDGEP(2) VUBEAM(2) VUGJUMP(2)GMBNDS PINTC VUGRIDGMCORD PINTS VUHEXA(2)(1) Denotes case control command.(2) Denotes parameter.

The p-element capability is still available in the software.

Removing documentation for curved elementsThe following bulk entries that support the curved element capability are removed from thedocumentation.

DVGEOM GMBC GMLOAD GMSURFFEEDGE GMCURV GMSPC TABLE3DFEFACE

The curved element capability is still available in the software.

Addition of element utilization summary tables in the QRGBeginning with NX Nastran 8, a series of tables were added to the NX Nastran User’s Guide thatsummarize element applicability for SOLs 101–200, and summarize valid combinations of elements,properties, and materials.

Beginning with NX Nastran 11, these tables are updated to include all new element types, materialtypes, and SOL 401. The updated tables are also moved from the NX Nastran User’s Guide to theNX Nastran Quick Reference Guide where they are placed in the Element Utilization Summarysection of the Bulk Data Entries chapter.



Documentation changes

Element Applicability Table

Table 12-1. Element Applicability for Solutions 101–401Nonlinear Structural, SOLs 106

and 129Material NonlinearType Element

LinearStruc-tural

SOLs(a) Plastic NLElastic

Hyper-Elastic Creep

GeomNL(b)

Multi-stepStruc-turalSOL401(c)

HeatTransSOLs153and159

CBAR X XCBEAM X X(d) X XCBEND X X XCONROD X X(e) X(e) X XCROD X X(e) X(e) X(e) X X

Line

CTUBE X X(e) X(e) X XCQUAD4 X X X X X X XCQUAD8 X X XCQUADR X XCRAC2D XCSHEAR XCTRIA3 X X X X X X XCTRIA6 X X X

Shell

CTRIAR X XCQUADX4 X X X XCQUADX8 X X X XCTRAX3 X X X XCTRAX6 X X X X

Axi-sym

CCHOCKi XCPLSTNi X(f) X X2D

Solid CPLSTSi X(f) X XCHEXA X X X X X X X XCHEXCZ XCPENTA X X X X X X X XCPENTCZ XCPYRAM X X X X X X XCRAC3D X

3DSolid

CTETRA X X X X X X X X(a) Includes SOLs 101, 103, 105, 107, 108, 109, 110, 111, 112, 114, 115, 116, 118, 144,145, 146, 187, and 200.(b) Small strain only. For large strain, refer to the hyperelasticity column.(c) SOL 401 supports linear, plasticity, creep, and geometric nonlinear structuralanalyses.(d) Elastic-perfectly plastic material behavior used to model the ends of beams asplastic hinges.(e) Nonlinear capability for axial deflections only.(f) Not supported for use in SOLs 114, 115, 116, 118, 144, 145, and 146.




Element-Property-Material Cross-Reference Tables

Table 12-2. Element-Property-Material Cross-Reference TablesElement Type Elements Table

Line CBAR, CBEAM, CBEND, CONROD, CROD, CTUBE 12-3

Shell CQUAD4, CQUAD8, CQUADR, CRAC2D, CSHEAR, CTRIA3, CTRIA6, CTRIAR 12-4

Axisymmetric CCHOCK3, CCHOCK4, CCHOCK6, CCHOCK8, CQUADX4, CQUADX8, CTRAX3, CTRAX6 12-5

2D Solid CPLSTN3, CPLSTN4, CPLSTN6, CPLSTN8, CPLSTS3, CPLSTS4, CPLSTS6, CPLSTS8 12-6

3D Solid CHEXA, CHEXCZ, CPENTA, CPENTCZ, CPYRAM, CRAC3D, CTETRA 12-7

Special Purpose

CAABSF, CAERO1, CAERO2, CAERO3, CAERO4, CAERO5, CBEAR, CBUSH, CBUSH1D,CDAMP1, CDAMP2, CDAMP3, CDAMP4, CDAMP5, CDUM1, CDUM2, CDUM3, CDUM4, CDUM5,CDUM6, CDUM7, CDUM8, CDUM9, CELAS1, CELAS2, CELAS3, CELAS4, CFAST, CGAP, CHACAB,CHACBR, CHBDYE, CHBDYG, CHBDYP, CMASS1, CMASS2, CMASS3, CMASS4, CONM1,CONM2, CONV, CONVM, CVISC, CWELD, RBAR, RBE1, RBE2, RBE3

12-8

Table 12-3. Line Elements: Supplemental Materials by Primary Material, Property,and Element

Supplemental Material

MATiElement Property PrimaryMaterial

CRP DMG FT S1 T1 T2 T3 T4 T5 T8 T9 T11CREEP

MAT1 X

MAT4 XPBAR

MAT5 X

MAT1 X

MAT4 X

CBAR

PBARL

MAT5 X

MAT1 X(1) X

MAT4 XPBEAM

MAT5 X

MAT1 X

MAT4 XPBEAML

MAT5 X

MAT1 X(1) X

MAT4 X

CBEAM

PBCOMP

MAT5 X

MAT1 X

MAT4 XCBEND PBEND

MAT5 X

MAT1 X(2) X

MAT4 XCONROD N/A

MAT5 X




Table 12-3. Line Elements: Supplemental Materials by Primary Material, Property,and Element




MAT1 X(2) X X(2)

MAT4 XCROD PROD

MAT5 X

MAT1 X(2) X

MAT4 XCTUBE PTUBE

MAT5 X(1) For material nonlinear analysis, elastic-perfectly plastic material behavior only. Strain hardening is not supported. The ends of the element aremodeled as plastic hinges.(2) Nonlinear capability for axial deflections only.

Table 12-4. Shell Elements: Supplemental Materials by Primary Material, Property,and Element




MAT1 X X X

MAT2 X X X

MAT4 X

MAT5 X

PSHELL

MAT8 X X X

MAT1 X

MAT2 XPCOMP

MAT8 X

MAT1 X

MAT2 XPCOMPG

MAT8 X

PLPLANE MATHP

CQUAD4CTRIA3

N/A MFLUID

MAT1 X

MAT2 X

MAT4 X

MAT5 X

PSHELL

MAT8 X

MAT1 X

MAT2 XPCOMP

MAT8 X

MAT1 X

MAT2 XPCOMPG

CQUAD8CTRIA6




Table 12-4. Shell Elements: Supplemental Materials by Primary Material, Property,and Element




MAT8 X

PLPLANE MATHP

MAT1 X

MAT2 X

MAT4 X

MAT5 X

PSHELL

MAT8 X

MAT1 X

MAT2 XPCOMP

MAT8 X

MAT1 X

MAT2 X

CQUADRCTRIAR

PCOMPG

MAT8 X

MAT1 X

MAT2 XCRAC2D PRAC2D

MAT8 X

CSHEAR PSHEAR MAT1

Table 12-5. Axisymmetric Elements: Supplemental Materials by Primary Material, Property, andElement




MAT1 X X X XCCHOCK3CCHOCK4CCHOCK6CCHOCK8

PCHOCKMAT11 X X X X

MAT1 X X

MAT3 X

MAT4 X

MAT5 X

MAT9 X X

PSOLID

MAT11 X X

CQUADX4CQUADX8CTRAX3CTRAX6

PLSOLID MATHP




Table 12-6. 2D Solid Elements: Supplemental Materials by Primary Material,Property, and Element




MAT1 X X

MAT3 X

MAT4 X

MAT5 X

PPLANE

MAT11 X X

MAT1 X X

CPLSTN3CPLSTN4CPLSTN6CPLSTN8

PGPLSNMAT11 X X

MAT1 X X

MAT3 X

MAT4 X

MAT5 X

CPLSTS3CPLSTS4CPLSTS6CPLSTS8

PPLANE

MAT11 X X





MAT1 X X X X

MAT4 X

MAT5 X

MAT9 X X X X

MAT10

MAT11 X X X X

PSOLID

MATPOR

PLSOLID MATHP

MAT1 X X X X

MAT9 X X X

CHEXACPENTA

PCOMPS

MAT11 X X X X

MAT1 X

MAT11 XCHEXCZCPENTCZ PSOLCZ

MATCZ








MAT1 X X X X

MAT4 X

MAT5 X

MAT9 X X X X

MAT10

MAT11 X X X X

CPYRAM PSOLID

MATPOR

MAT1 XCRAC3D PRAC3D

MAT9 X

MAT1 X X X X

MAT4 X

MAT5 X

MAT9 X X X X

MAT10

MAT11 X X X X

PSOLID

MATPOR

CTETRA

PLSOLID MATHP




Table 12-8. Special Purpose Elements: Supplemental Materials by Primary Material,Property, and Element




CAABSF PAABSF N/A

CAEROi (1) PAEROi (1) N/A

CBEAR PBEAR N/A

CBUSH PBUSH (2) N/A

CBUSH1D PBUSH1D N/A

CDAMP1 PDAMP N/A

CDAMP2 N/A N/A

CDAMP3 PDAMP N/A

CDAMP4 N/A N/A

MAT4 XCDAMP5 PDAMP5

MAT5 X

CDUMi (3) PDUMi (3) (4)

CELAS1 PELAS N/A

CELAS2 N/A N/A

CELAS3 PELAS N/A

CELAS4 N/A N/A

CFAST PFAST N/A

CGAP PGAP N/A

CHACAB PACABS N/A

CHACBR PACBAR N/A

CHBDYE N/A N/A

CHBDYG N/A N/A

CHBDYP PHBDY N/A

CMASS1 PMASS N/A

CMASS2 N/A N/A

CMASS3 PMASS N/A

CMASS4 N/A N/A

CONMi (5) N/A N/A

CONV PCONV MAT4 X

CONVM PCONVM MAT4 X

CVISC PVISC N/A

CWELD PWELD MAT1

RBAR N/A N/A

RBEi (6) N/A N/A(1) i = 1 through 5(2) Use a PBUSHT entry with the same PID as a PBUSH entry to define frequency dependent or stress dependent properties.(3) i = 1 through 9(4) Per user definition.(5) i = 1 and 2(6) i = 1, 2, and 3



Chapter 13: Upward compatibility

Updated data blocks

CASECC

Updated Record - REPEAT

Word Name Type Description

...... ...... ...... ......

489 RANLOOP I RANDOM loop number; used with ANALYSIS =RANDOM

...... ...... ...... ......

...... ...... ...... ......

561 INITSSET I Initial stress/strain case control setting. INITS=nwith n=SID of INITS or INITADD bulk entry. n=0 fornone (default). n>0 is the INITS SID or INITADDSID.

562 OSTNSET I Set no for initial strain output after subcase 0

...... ...... ...... ......

...... ...... ...... ......

565 BOLTRESMED I Bolt axial force, shear force, bending moment, andstrain output media

566 CYCLSET I SOL 401 cyclic symmetry set IF (CYCSET)

567 OSTNOPT I Output options for initial strain after subcase 0: =1for element-node; =2 for Gauss; = 3 for both. (ForINITSTN/INITSTS)

568 OSTNMED I Media for initial strain output after subcase 0;PRINT/PUNCH/PLOT. (For INITSTN/INITSTS)

569 ACPWRGST I Acoustic power, GROUP output set (ACPOWER)

570 ACPWRAST I Acoustic power, AMLREG output set (ACPOWER)

571 ACPWRDIA I Acoustic power, output media (ACPOWER)




572 ACPWRFMT I Acoustic power, output format (ACPOWER)

573 MPINTSET I Microphone point intensity, output set(MPINTENSITY)

574 MPINTDIA I Microphone point intensity, output media(MPINTENSITY)

575 MPINTFMT I Microphone point intensity, output format(MPINTENSITY)

576 MPPRESET I Microphone point pressure, output set(MPPRESSURE)

577 MPPREDIA I Microphone point pressure, output media(MPPRESSURE)

578 MPPREFMT I Microphone point pressure, output format(MPPRESSURE)

579 MPVELSET I Microphone point velocity, output set(MPVELOCITY)

580 MPVELDIA I Microphone point velocity, output media(MPVELOCITY)

581 MPVELFMT I Microphone point velocity, output format(MPVELOCITY)

582 PFRESUSET I Progressive failure analysis of composites, outputset (PFRESULTS)

583 PFRESUDIA I Progressive failure analysis of composites, outputmedia (PFRESULTS)

584 PFRESUFMT I Progressive failure analysis of composites, outputcode for damage value/damage status/damageenergy (PFRESULTS)

585 MONVAR I Maya monitor variable for displacement

586 CYCFSET I Forces of cyclic constraint output set (CYCFORCE)

587 CYCMEDIA I Forces of cyclic constraint output media(CYCFORCE)

588 CYCFFMT I Forces of cyclic constraint output format(CYCFORCE)

589 BOLTRESULTS I Bolt axial force, shear force, bending moment, andstrain



Upward compatibility


590 STVARSET I State variable values on elements, output set(STATVAR)

591 STVARMEDIA I State variable values on elements, output media(STATVAR)

592 STVARFMT I State variable values on elements, output format(STATVAR)

593 CZRESUSET I Cohesive elements, output set (CZRESULTS)

594 CZRESUDIA I Cohesive elements, output media (CZRESULTS)

595 CZRESUFMT I Cohesive elements, output code for traction/relativemotion/damage value (CZRESULTS)

596 CKGAPSET I Gap results, output set (CKGAP)

597 CKGAPDIA I Gap results, output media (CKGAP)

598 CKGAPFMT I Gap results, output location: =1 for grid; =2 forGauss; =3 for both (CKGAP)

599 UNDEF None

...... ...... ...... ......

CLAMA

Updated Record 1 – OFPID


...... ...... ...... ......

11 RSPEED RS Rotor speed in RUNIT units; P value forRUNIT = SYNC

12 RUNIT CHAR4 RSPEED units; RPM, CPS, HZ, or RAD;blank or integer 0 in a non-rotor dynamicanalysis; SYNC for synchronous

13 SUBC I Subcase ID

14 UNDEF(37) None

...... ...... ...... .......




CONTACT

New Record - AMLREG(811,8,628)


1 RID I AML region ID

2 SID I BSURFS ID for surface definition

3 DESC(12) CHAR4 Description - 48 character maximum

15 NLAY I Number of layers

16 RADTYPE I Radiation surface type:

0=None

1=AML

2=Physical boundary

17 INFID1 I Infinite plane-1 ID



20 UNDEF(3) None

New Record - IPLANE(911,9,629)


1 IPID I Infinite plane ID for AMLREG

2 SYM I Symmetry flag:

0=Symmetric

1=Unsymmetric

3 BID I Surface ID to BSURFS; 0 if CID is used

4 CID I Rectangular coordinate system ID; 0 if BID is used

5 CSP I Coordinate system plane; 1=XY, 2=YZ, 3=XZ; 0 ifBID is used

6 UNDEF(10) None




Updated Record - Trailer


1 BIT(6) I Record presence trailer words

DYNAMIC

New Record – RCROSS(3201,24,54)


1 SID I Set identification number

2 RTYPE1 CHAR4 First response quantity type

3 ID1 I Element, grid, or scalar identification number of firstresponse quantity

4 COMP1 I Component code (item) identification number of firstresponse quantity

5 RTYPE2 CHAR4 Second response quantity type

6 ID2 I Element, grid, or scalar identification number ofsecond response quantity

7 COMP2 I Component code (item) identification number ofsecond response quantity

8 CURID I Optional curve identification number

New Record – RCROSSC(3501,35,56)



2 RTYPE1 CHAR4 First response quantity type

3 ID1 I Element identification number of first responsequantity

4 COMP1 I Component code (item) identification number of firstresponse quantity

5 PLY1 I Ply number of first response quantity

6 UNDEF(4) None

10 RTYPE2 CHAR4 Second response quantity type





11 ID2 I Element identification number of second responsequantity

12 COMP2 I Component code (item) identification number ofsecond response quantity

13 PLY2 I Ply number of second response quantity

14 UNDEF(5) None

16 CURID I Optional curve identification number

New Record – ROTPARM(9310,93,633)



2 PARAM(2) CHAR4 Parameter name

4 VALU RS Value of parameter

Words 2 through 4 repeat until (-1,-1,-1) occurs

EDOM

Updated Record – DOPTPRM(4306,43,364)


...... ...... ....... ......

45 EDVOUT RS Fraction of DVEREL1 DESVARs to be output in f06file

New Record – DVEREL1(5706,57,634)


1 ID I Unique identification number

2 TYPE(2) CHAR4 Name of property entry (PSHELL is the only optionfor NX Nastran 11)

4 GRPID I Identification number of a GROUP entry thatcontains the elements to be referenced byDVEREL1 (ELEM is the only GROUP option for NXNastran 11)





5 FID I Entry is 0

6 PMIN RS Minimum value allowed for this property

7 PMAX RS Maximum value allowed for this property

8 UNDEF None

9 PNAME(2) CHAR4 Currently T supported only

11 DVID1 I DESVAR entry identification number for first ofauto-generated design variables. Integer>0. Defaultis 0, which means that the design variable IDs willbe the same as the IDs of the elements with theproperties that will be associated with the designvariables.

12 COEF1 RS Coefficient in the expression P = COEF1*DV. Thedefault value is 1.0.

EDT

Updated Record – ACMODL(5201,52,373)


...... ...... ...... ......

17 CTYPE(2) CHAR4 Coupling type (STRONG, WEAK, WEAKINT, orWEAKEXT)

Updated Record – GROUP(17400,174,616)


1 GID I Group identification number

2 NDESC(C) I Length of group description

3 GDESC(2) CHAR4 Group description

Word 3 repeats NDESC times

NDESC+3 GTYPE I Group type-2 = Meta data-3 = Property identification numbers-4 = Grid identification numbers-5 = Element identification numbers





GTYPE = -2 Meta data

NDESC+4 NMETA I Length of meta data (includes -1 terminator)

NDESC+5 MDESC(2) CHAR4 Meta data

Word NDESC+5 repeats NMETA times

GTYPE = -3 Property identification numbers

NDESC+5+NMETA

ID I Property identification numbers> 0 for ID= 0 for THRU= -6 for BY= -7 for ALL

Word NDESC+5+NMETA repeats until -1 occurs

GTYPE = -4 Grid identification numbers

NDESC+5+NMETA

ID I Grid identification numbers> 0 for ID= 0 for THRU= -6 for BY= -7 for ALL


GTYPE = -5 Element identification numbers

NDESC+5+NMETA

ID I Element identification numbers> 0 for ID= 0 for THRU= -6 for BY= -7 for ALL


EPT

New Record - PCHOCK(8801,88,955)


1 PID I Property identification number

2 MID I Material identification number

3 NGAP I Number of gaps





4 GAPT RS Initial gap opening of each gap

5 UNDEF(4)

New Record - PSOLCZ(8901,89,905)




3 CORDM I Material coordinate system identification number

4 THICK RS Thickness of cohesive element

5 UNDEF(4)

EPT705

New Record - PCHOCK(8801,88,955)




3 NGAP I Number of gaps

4 GAPT RS Initial gap opening of each gap

5 UNDEF(4)

New Record - PSOLCZ(8901,89,905)




3 CORDM I Material coordinate system identification number

4 THICK RS Thickness of cohesive element

5 UNDEF(4)




GEOM2

New RECORD – CCHOCK3(14801,148,956)


1 EID I Element identification number


3 G(3) I Grid point identification numbers of connectionpoints

4 UNDEF None

5 THETA RS Material property orientation angle

6 UNDEF(5) None

11 GAP(3) RS Separation for a single GAP at grid points

12 UNDEF None

New RECORD – CCHOCK4(14901,149,957)






5 UNDEF(5) None


New RECORD - CCHOCK6(15001,150,958)





4 UNDEF(2) None






7 UNDEF None


9 UNDEF None

New RECORD - CCHOCK8(15101,151,959)






5 UNDEF None


7 UNDEF(8) None

New RECORD - CHEXAF(14100,141,9905)

Same as record CHEXA description.

New RECORD - CHEXCZ(11801,118,907)





4 UNDEF(2) None

New RECORD - CPENTAF(14200,142,9906)

Same as record CPENTA description.




New RECORD - CPENTCZ(11901,119,908)





4 UNDEF(7) None

New RECORD - CPYRAMF(14400,144,9908)

Same as record CPYRAM description.

New RECORD - CQUADF(14600,146,9910)

Same as record CQUAD4 description.

New RECORD - CRODF(14500,145,9909)

Same as record CROD description.

New RECORD - CTETRAF(14300,143,9907)

Same as record CTETRA description.

New RECORD - CTRIAF(14700,147,9911)

Same as record CTRIA3 description.

New RECORD - MICPNT(2801,28,630)



2 GID I Fluid grid identification number

3 DESC(12) CHAR4 Description - 48 characters maximum

Previously undocumented RECORD - ENDOFDB(65535,65535,65535)

End of data block.




GEOM3

New Record - RFORCE2(17600,176,627)


1 SID I Load set identification number

2 G I Grid point identification number

3 CID I Coordinate system identification number

4 A RS Scale factor of the angular velocity

5 R(3) RS Rectangular components of rotation vector

8 METHOD I Method used to compute centrifugal forces

9 RACC RS Scale factor of the angular acceleration

10 MB I Bulk Data Section with CID definition: -1=main;0=partitioned

11 GYROP I Process option: 0=both centrifugal force (CF) andgyroscopic force (GF); 1=CF only; 2=GF only

New Record - BOLTFRC(9709,97,635)


1 SID I BOLTFRC identification number

2 TYPE CHAR8 LOAD or STRAIN or DISP

4 VALUE RS Preload or initial strain or displacement

5 LEN RS Length of bolt if TYPE = DISP

6 BID I Bolt set ID

Word 6 repeats until -1 occurs

New Record - BOLTSEQ(9009,90,639)


1 SID I BOLTSEQ identification number

2 UNDEF(7) None

9 LIN I Bolt load index number





10 LID I Bolt load ID

11 INC I Number of increments

Words 9 through 11 repeats until -1 occurs

GEOM4

New RECORD – CYCADD(8420,84,641)


1 ID I

2 G1 I


New RECORD – CYCAXIS(8510,85,643)


1 CSID I Coordinate system ID for cyclic analysis

New RECORD - CYCSET(8220,82,640)


1 CYSID I CYCSET set identification numbers

2 NSEG I Number of segments

3 CSID I Coordinate system ID for cyclic set

4 UNDEF(3)

7 SID I Source region ID

8 TID I Target region ID

9 SDIST RS Tolerance distance for CYCSET regions

Words 7 through 9 repeat until -1 occurs

Previously undocumented RECORD - ENDOFDB(65535,65535,65535)

End of data block.




GEOM4705

New Record - CYCADD(8420,84,641)


1 ID I

2 G1 I


New Record - CYCAXIS(8510,85,643)


1 CSID I Coordinate system ID for cyclic analysis


New Record - CYCSET(8220,83,640)


1 CYSID I CYCSET set identification numbers

2 NSEG I Number of segments

3 CSID I Coordinate system ID for cyclic set

4 UNDEF(3)

7 SID I Source region ID

8 TID I Target region ID

9 SDIST RS Tolerance distance for CYCSET regions


MPT

New RECORD – MATCZ(5303,53,906)


1 MID I Material identification number of cohesiveelement

2 DLAW I Damage law





DLAW = 1 Polynomial law

3 TANG I Tangent of constitutive law

4 TAU RS Time for delay

5 ADEL RS Parameter for delay

6 UNDEF(3) None

9 K03S RS Transverse stiffness

10 K02 RS Shear stiffness

11 K01 RS Second shear stiffness

12 GIC RS Critical energy release rate I

13 GIIC RS Critical energy release rate II

14 GIIIC RS Critical energy release rate III

15 DCOU RS Coupling coefficient

16 Y0S RS Thermodynamic force

17 EXPN RS Exponent

18 UNDEF(7) None

DLAW = 2 Bi-triangular law




6 UNDEF(3) None












16 Y0S RS Thermodynamic force

17 UNDEF(8) None

DLAW = 3 Exponential law




6 UNDEF(3) None








16 UNDEF(9) None

New RECORD – MATDMG(5101,51,642)


1 MID I Material identification number of progressivedamage of composite layer

2 PPFMOD I Damage model for PFA, "UD" = 1

3 UNDEF(6) None

9 Y012 RS Fiber/matrix de-bonding threshold

10 YC12 RS Critical thermodynamic force

11 YS12 RS Transverse fissuration threshold

12 YS22 RS Transverse fissuration threshold

13 Y11LIMT RS Breaking thresholds in tension





14 Y11LIMC RS Breaking thresholds in compression

15 KSIT RS Non-linearity coefficients in tension

16 KSIC RS Non-linearity coefficients in compression

17 B2 RS Coupling coefficient

18 B3 RS Coupling coefficient between the damage variables

19 A RS Coupling coefficient (plasticity)

20 LITK RS Initial plastic threshold

21 BIGK RS Parameter of plastic law

22 EXPN RS Exponent of plastic law



25 PLYUNI I Indicator whether non-linearity coefficients of E1are applied to stresses (INDIC=zero) or strain(INDIC=non-zero)

26 TID I Identification number of a TABLEDi entry fornonlinear shear damage

27 HBAR RS Transition thickness

28 DMAX RS Maximum value of damage

29 PE I Indicator for damage effect in out-of-plane direction

30 UNDEF(3) None

New RECORD – MATPOR(4801,48,961)



2 MODEL CHAR4 Absorber model

MODEL = 1 Craggs model

3 RHO RS Mass density

4 C RS Speed of sound





5 UNDEF(4) None

9 RES RS Flow resistivity

10 POR RS Porosity

11 TORT RS Tortuosity

12 UNDEF(5) None

MODEL = 2 Delaney-Miki model



5 FRAME I FRAME = 1 for rigid; FRAME = 2 for limp

6 UNDEF(3) None

9 RES RS Speed of sound

10 POR RS Porosity

11 UNDEF RS

12 DENS RS Frame density (for limp frames only)

13 UNDEF(4) RS

MODEL = 3 Johnson-Champoux-Allard model



5 FRAME I FRAME = 1 for rigid; FRAME = 2 for limp

6 GAMMA RS Ratio of constant pressure specific heat toconstant volume specific heat

7 PR RS Prandtl number

8 MU RS Dynamic viscosity

9 RES RS Speed of sound

10 POR RS Porosity

11 TORT RS Tortuosity

12 DENS RS Frame density (for limp frames only)





13 L1 RS Characteristic viscous length

14 L2 RS Characteristic thermal length

15 UNDEF(2) None

New RECORD – MUMAT(4401,44,962)



2 MODNAME1(2) CHAR4 Material model name

4 MODNAME2(2) CHAR4 Material model name

6 NUMSTAT I Number of state variables

7 MATNAME(2) CHAR4 Material name

9 SETID I Identification number of SET1 entry

10 UNDEF(2) None

CONST = 1 Integer constants

12 CONST I Constants


CONST = 2 Real constants

12 CONST RS Constants


ID = 3 TABLES1 IDs

12 ID I > 0 for ID


ID = 4 TABLEST IDs

12 ID I > 0 for ID


ID = 5 TABLEM1 IDs

12 ID I > 0 for ID






OCCORF

Updated Record 1 - IDENT


...... ...... ...... ......

7 CMPFLAG I Composite flag = 0

8 UNDEF none

9 FCODE I Format Code

10 NUMWDE(C) I Length of entries in RECORD=DATA (always 2)

...... ...... ...... ......

OCPSDF

Updated Record 1 - IDENT


...... ...... ...... ......


8 UNDEF none

...... ...... ...... ......

OEE

Updated Record - IDENT


...... ....... ...... ......

22 THRESH RS Energy Threshold

23 THERMAL I THERMAL = 1 for heat transfer; = 2for axisymmetric Fourier; = 3 for cyclicsymmetric; = 0 otherwise





24 UNDEF(2) None

26 HINDEX I Harmonic index

27 SCFLAG I Sine/cosine flag. SCFLAG = 0 for 0thharmonic; = 1 for cosine component; = 2for sine component; = -1 (default) for othersolution type output

28 UNDEF(23) None

51 TITLE(32) CHAR4 Title

...... ...... ...... ......

OES



...... ....... ...... ......

21 RUNIT CHAR4 RSPEED units; RPM, CPS, HZ, or RAD;blank or integer 0 in a non-rotor dynamicanalyses

22 UNDEF None

23 THERMAL I THERMAL = 1 for heat transfer; = 2 foraxisymmetric Fourier; = 3 for cyclic symmetric

24 UNDEF(2) None



28 UNDEF(23) None


...... ...... ...... ......




Updated Record - DATA

ELTYPE =269 Composite HEXA element (CHEXAL)

2 PLY I Lamina number

SCODE,6=0 Strain

TCODE,7 =0 Real

Q4CSTR=0 Center option

3 FLOC CHAR4 Fiber location (BOT, MID, TOP)

4 GRID I Edge grid ID (center=0)

5 E11 RS Normal strain in the 1-direction



8 E12 RS Shear strain in the 12-plane



11 ETMAX1 RS von Mises strain

Q4CSTR=1 Center and Corner option









11 ETMAX1 RS Von Mises strain

For each fiber location requested (PLSLOC), words 4 through 11 repeat 5 times.

TCODE,7 =1 Real/imaginary






4 GRID I Edge grid ID (Center = 0)

5 E11r RS Normal strain in the 1-direction, real part



8 E12r RS Shear strain in the 12-plane, real part



11 E11i RS Normal strain in the 1-direction, imaginary part



14 E12i RS Shear strain in the 12-plane, imaginary part

15 EL23i RS Shear strain in the 23-plane, imaginary part

16 EL13i RS Shear strain in the 13-plane, imaginary part




















TCODE,7 =2 Random Response




















End TCODE,7

SCODE,6=1 Stress

TCODE,7 =0 Real







5 S11 RS Normal stress in the 1-direction



8 S12 RS Shear stress in the 12-plane



11 STMAX1 RS Von Mises stress
















5 S11r RS Normal stress in the 1-direction, real part



8 S12r RS Shear stress in the 12-plane, real part






11 S11i RS Normal stress in the 1-direction, imaginary part



14 S12i RS Shear stress in the 12-plane, imaginary part










































End TCODE,7

End SCODE,6

ELTYPE =270 Composite PENTA element (CPENTAL)


SCODE,6=0 Strain

TCODE,7 =0 Real





















End TCODE,7

SCODE,6=1 Stress

TCODE,7 =0 Real





















End TCODE,7

End SCODE,6

ELTYPE =304 Linear composite HEXA element (CHEXAL)


SCODE,6=0 Strain



4 EX1 RS Normal strain in the 1-direction

5 EY1 RS Normal strain in the 2-direction

6 EZ1 RS Normal strain in the 3-direction

7 ET1 RS Shear strain in the 12-plane

8 EL2 RS Shear strain in the 23-plane




SCODE,6=1 Stress



4 SX1 RS Normal stress in the 1-direction

5 SY1 RS Normal stress in the 2-direction

6 SZ1 RS Normal stress in the 3-direction

7 ST1 RS Shear stress in the 12-plane

8 SL2 RS Shear stress in the 23-plane





10 STMAX1 RS von Mises stress


End SCODE,6

ELTYPE =305 Linear composite PENTA element (CPENTAL)


SCODE,6=0 Strain











SCODE,6=1 Stress














End SCODE,6

ELTYPE =306 Nonlinear composite HEXA element (CHEXALN)


SCODE,6=0 Strain











SCODE,6=1 Stress














End SCODE,6

ELTYPE =307 Nonlinear composite PENTA element (CPENTALN)


SCODE,6=0 Strain











SCODE,6=1 Stress











End SCODE,6




ELTYPE =337 Chocking triangular element (CHOCK3)

SCODE,6=0 Strain

TODE,7=0 Real

1 CID I Coordinate system

2 CTYPE CHAR4 Grid or Gauss

3 GRID I External grid ID

4 EX RS Normal strain in the X-direction

5 EY RS Normal strain in the Y-direction

6 EZ RS Normal strain in the Z-direction

7 EXY RS Shear strain in the XY-plane

8 EYZ RS Shear strain in the YZ-plane

9 EZX RS Shear strain in the ZX-plane

10 EVM RS von Mises strain

Words 3 through 10 repeat 3 times.

SCODE,6=1 Stress

TCODE,7=0 Real


4 SX RS Normal stress in the X-direction

5 SY RS Normal stress in the Y-direction

6 SZ RS Normal stress in the Z-direction

7 SXY RS Shear stress in the XY-plane

8 SYZ RS Shear stress in the YZ-plane

9 SZX RS Shear stress in the ZX-plane

10 SVM RS von Mises stress


End SCODE,6




ELTYPE =338 Chocking quad element (CHOCK4)

SCODE,6=0 Strain

TODE,7=0 Real












SCODE,6=1 Stress

TCODE,7=0 Real










End SCODE,6





SCODE,6=0 Strain

TODE,7=0 Real












SCODE,6=1 Stress

TCODE,7=0 Real










End SCODE,6




ELTYPE =341 Shell triangular element (TRIA3)

SCODE,6=0 Strain

TODE,7=0 Real

1 THETA RS



4 FD1 RS Fiber distance at z1

















SCODE,6=1 Stress

TCODE,7=0 Real






















End SCODE,6

ELTYPE =342 Shell quad element (QUAD4)

SCODE,6=0 Strain

TODE,7=0 Real

1 THETA RS























SCODE,6=1 Stress

TCODE,7=0 Real






















End SCODE,6

ELTYPE =343 Shell triangular element (TRIA6)

SCODE,6=0 Strain

TODE,7=0 Real

1 THETA RS























SCODE,6=1 Stress

TCODE,7=0 Real



















End SCODE,6

ELTYPE =344 Shell quad element (QUAD8)




SCODE,6=0 Strain

TODE,7=0 Real

1 THETA RS




















SCODE,6=1 Stress

TCODE,7=0 Real






















End SCODE,6

ELTYPE =345 Shell quad element (QUADR)

SCODE,6=0 Strain

TODE,7=0 Real

1 THETA RS























SCODE,6=1 Stress

TCODE,7=0 Real






















End SCODE,6

ELTYPE =346 Shell triangular element (TRIAR)

SCODE,6=0 Strain

TODE,7=0 Real

1 THETA RS























SCODE,6=1 Stress

TCODE,7=0 Real



















End SCODE,6

OESVM


For the following element types, the order that the components of stress and strain are listed in thedata block has changed from X1, Y1, T1, Z1, L1, L2, to X1, Y1, Z1, T1, L2, L1.




ELTYPE =269 Composite HEXA element (CHEXAL)


SCODE,6=0 Strain

TCODE,7 =0 Real











Q4CSTR=1 Corner option
























11 EX1I RS Normal strain in the 1-direction

12 EY1I RS Normal strain in the 2-direction

13 EZ1I RS Normal strain in the 3-direction

14 ET1I RS Shear strain in the 12-plane

15 EL2I RS Shear strain in the 23-plane


17 EVM RS von Mises



















17 EVM RS von Mises


End TCODE,7

SCODE,6=1 Stress

TCODE,7 =0 Real



































11 SX1I RS Normal stress in the 1-direction

12 SY1I RS Normal stress in the 2-direction

13 SZ1I RS Normal stress in the 3-direction

14 ST1I RS Shear stress in the 12-plane

15 SL2I RS Shear stress in the 23-plane


17 SVM RS von Mises



















17 SVM RS von Mises


End TCODE,7

End SCODE,6

ELTYPE =270 Composite PENTA element (CPENTAL)


SCODE,6=0 Strain

TCODE,7 =0 Real









































17 EVM RS von Mises



















17 EVM RS von Mises


End TCODE,7

SCODE,6=1 Stress

TCODE,7 =0 Real









































17 SVM RS von Mises



















17 SVM RS von Mises


End TCODE,7

End SCODE,6

ELTYPE =304 Linear composite HEXA element (CHEXAL)


SCODE,6=0 Strain














SCODE,6=1 Stress











End SCODE,6

ELTYPE =305 Linear composite PENTA element (CPENTAL)


SCODE,6=0 Strain














SCODE,6=1 Stress











End SCODE,6

ELTYPE =306 Nonlinear composite HEXA element (CHEXALN)


SCODE,6=0 Strain














SCODE,6=1 Stress











End SCODE,6

ELTYPE =307 Nonlinear composite PENTA element (CPENTALN)


SCODE,6=0 Strain














SCODE,6=1 Stress











End SCODE,6

OESXRMS


For the following element types, the order that the components of stress are listed in the data blockhas changed from SX1, SY1, ST1, SZ1, SL1, SL2, to SX1, SY1, SZ1, ST1, SL2, SL1.

ELTYPE =269 Composite HEXA element (CHEXAL) – Center and corners


























ELTYPE =270 Composite PENTA element (CPENTAL) – Center and corners


























OGF



...... ....... ...... ......

16 FREQ RS Natural frequency

17 UNDEF(6) None


24 UNDEF(2) None



28 UNDEF(23) None


...... ...... ...... ......




OPRESS



...... ...... ...... ......

3 ECODE I Element code

4 SUBCASE I Subcase ID

5 TIMESTEP RS Current time step

6 PCODE(C) I PLOAD code

7 UNDEF(3) None

10 NUMWDE I Number of words per entry in DATA record

...... ....... ...... ......

OQG



...... ....... ...... ......

17 RMSSF RS RMS and CRMS scale factor

18 UNDEF(5) None


24 UNDEF(2) None



28 UNDEF(23) None


...... ...... ...... ......




OUG



...... ....... ...... ......

17 RMSSF RS RMS and CRMS scale factor

18 UNDEF(5) None


24 RSPEED RS Rotor speed in RUNIT units

25 RUNIT CHAR4 RSPEED units; RPM, CPS, HZ, or RAD;blank or integer 0 in a non-rotor dynamicanalyses



28 UNDEF(23) None


...... ...... ...... ......

SETMC

New RECORD – SETMC(120,12,9938)


1 SID I Subcase identification number

2 SETMCID I SETMC identification number

3 SETMCLEN I SETMC data length

4 SMCODE I SETMC type code

5 GRIDID I Grid identification number

6 DOFID I DOF identification number





Words 5 and 6 repeat until (-99,-99) occurs


New RECORD – STMCNAME(110,11,9937)


1 SETID I SETMC identification number

2 SETNAME(15) CHAR4 SETMC name

New data blocks

ELRSCALV

Normalized material density for topology optimization output

Record - HEADER


1 NAME(2) CHAR4 Data block Name

Record - IDENT


1 ACODE(C) I Device code + 10*Approach CodeValue =11 for printed static results

2 TCODE(C) I Table Code:Value = 68 for elemental, real scalar value

3 DATCOD I Data code: Not used. Value = 0

4 SUBCASE I Subcase or Random identification number

TCODE,1 =1 Sort 1

ACODE,4 =01 Statics (static and modal results are both designated as static)

5 LSDVMN I Load set number

6 UNDEF(2 ) None

End TCODE,1





8 RCODE I Value = 0

9 FCODE I Format Code Value =1 for real data

10 NUMWDE I Number of words per entry in DATA record.Value = 2 for element ID and scalar.

11 UNDEF(2) None

13 ACFLAG(C) I Not used. Value = 0

14 UNDEF(9) None

23 THERMAL I Not used. Value = 0

24 UNDEF(27)

51 TITLE(32) CHAR4 Title. Value = “Topology Optimization”

83 SUBTITL(32) CHAR4 Subtitle. Value = “NAMEKEY=NormalizedMaterial Density”

115 LABEL(32) CHAR4 Label. Not used.

Record - DATA


1 EKEY I Element ID

2 Value RS Scalar value for the element

Words 1 and 2 repeat for Nelements.

Record - TRAILER


1 UNDEF(6) None

OACCQ

Acoustic coupling information in SORT1 format




Record - HEADER


1 NAME(2) CHAR4 Data block name

Record - IDENT


1 ACODE(C) I Device code + 10*Approach code

2 TCODE(C) I Table code

3 DATCOD I Data code:

• 0 = coupled fluid

• 1 = uncoupled fluid

• 2 = coupled structure

• 3 = uncoupled structure

4 UNDEF(5)

9 FCODE(C) I Format code

10 NUMWDE(C) I Number of words per entry in DATA record

11 UNDEF(40) None

51 TITLE(32) CHAR4 Title character string (TITLE)

83 SUBTITL(32) CHAR4 Subtitle character string (SUBTITLE)

115 LABEL(32) CHAR4 LABEL character string (LABEL)

Record - DATA


1 ID I Element ID

2 GID1 I Corner grid 1



5 DIST RS Minimum projection distance to structure




Record - TRAILER


1 NUMREC0 I Number of records for DATCOD = 0




5 UNDEF(2) None

Notes:

1. Ident and Data records are repeated for coupled fluid, uncoupled fluid, coupled structure, anduncoupled structure.

OACINT

Acoustic intensity at fluid grids in SORT1 format

Record - HEADER



3 Word I No Def or Month, Year, One, One

Word 3 repeats until End of Record

Record - IDENT



2 TCODE(C) I Table code = 54

3 UNDEF

4 SUBCASE I Subcase identification number

5 FREQ RS Frequency (Hz)

6 UNDEF(3)






10 NUMWDE(C) I Number of words per entry in DATA record= 7

11 UNDEF(40) None




Record - DATA


1 GID I Fluid grid ID

2 INTR(3) RS Intensity components - real part

5 INTI(3) RS Intensity components - imaginary part

Record - TRAILER


1 NUMREC I Number of records

2 UNDEF(5) None

Notes:

1. Repeat data records for all fluid grids for intensity values at the frequency in word 5 of the Identrecord.

OACPRES

Acoustic pressure at microphone points in SORT1 and SORT2 formats

Record - HEADER








Record - IDENT




3 UNDEF


TCODE,1 = 01 SORT1 format



5 EID I Microphone point element ID

End TCODE,1

6 UNDEF(3)



11 UNDEF(40) None


83 SUBTITLE(32) CHAR4 Subtitle character string (SUBTITLE)


Record - DATA


TCODE,1 = 01 SORT1 Format

1 EID I Microphone point element ID



End TCODE,1

2 PRESR RS Pressure - real part

3 PRESI RS Pressure - imaginary part




Record - TRAILER



2 UNDEF(5) None

Notes:

1. For SORT1, repeat Data record for all microphone points for pressure values at the frequency inword 5 of the Ident record.

2. For SORT2, repeat Data record for all frequencies for the microphone point listed in word 5of the Ident record.

OACPWR

Acoustic power in SORT1 and SORT2 formats

Record - HEADER





Record - IDENT




3 DATCOD I Data code; 10*SID for AMLREG, 10*SID+1for GROUP

4 SUBCAS I Subcase identification number



6 UNDEF(3) None






9 SID I AMLREG / GROUP ID

10 UNDEF(3) None

End TCODE,1



11 DESCR(12) CHAR4 AMLREG / GROUP description

23 UNDEF(28) None




Record - DATA



1 SID I AMLREG/GROUP ID



End TCODE,1

2 POWERR RS Power - real part

3 POWERI RS Power - imaginary part

Record - TRAILER



2 UNDEF(5) None

OACVELO

Acoustic velocity at fluid grids in SORT1 format




Record - HEADER





Record - IDENT




3 UNDEF

4 SUBCAS I Subcase identification number


6 UNDEF(3)



11 UNDEF(40)




Record - DATA


1 GID I Fluid grid ID

2 VELR(3) RS Velocity components - real part

5 VELI(3) RS Velocity components - imaginary part




Record - TRAILER



2 UNDEF(5) None

Notes:

1. Repeat Data record for all fluid grids for velocity values at the frequency in Word 5 of the IDENTrecord.

OBOLT

Table of bolt output

Record – HEADER



3 WORD I No Def or Month, Year, One, One

Record – IDENT


1 ACODE(C) I Device code + 10* Approach Code

2 TCODE(C) I Table code

3 BOLTID I Bolt ID

4 SUBCASE I Subcase that contains the bolt load

5 TIME RS Current time step

6 UNDEF(4) None

10 NUMWDE(C) I Number of words per entry in DATA record

11 CSID I Bolt coordinate system ID

12 IDIR I Bolt direction vector

13 UNDEF(38) None


83 SUBTITL(32) CHAR4 Subtitle





115 LABEL(32) CHAR4 Label

Record – DATA


1 EKEY I Device code + 10 * bolt element identificationnumber

NUMWDE = 7 3D solid elements

2 AX RS Axial force in bolt coordinate system

3 SHR1 RS Shear force 1 in bolt coordinate system


5 BEN1 RS Bending moment 1 in bolt coordinate system


7 STRN RS Bolt axial initial strain in bolt coordinate system

NUMWDE = 5 2D plane stress elements

2 AX RS Axial force in bolt coordinate system



5 STRN RS Bolt axial initial strain in bolt coordinate system

Record – TRAILER


1 UNDEF(6) None

OCCORFC

Table of cross-correlation functions for composites.

Record 0 – HEADER






Record 1 – IDENT



2 TCODE(C) I Table code; always 4200

3 UNDEF none

4 RANDID I RANDOM set identification number

5 DCODE I Device code +10*function number

6 RCROSSID I RCROSS identification number


8 UNDEF none

9 FCODE I Format Code


11 RTYPE1 CHAR4 Type of first response quantity

12 ID1 I Element, grid or scalar point ID number

13 COMP1 I Component code (item) ID number

14 PLY1 I Ply number

15 RTYPE2 CHAR4 Type of second response quantity

16 ID2 I Element, grid, or scalar point ID number



19 CURID I Curve ID number

20 UNDEF(31) none







Record 2 – DATA



2 CCORF RS Cross-correlation function

Record 3– TRAILER


1 WORD1 I Number of records

2 WORD2 I Number of data values in record 2.

3 UNDEF(4) none

OCKGAP1

Table of opening gap values for chocking elements

OCKGAP1G is the table of opening gap values at Gauss points for chocking elements.

Record - HEADER



3 WORD I No Def or Month, Year,One, One


Record - IDENT


1 ACODE(C) I Device code + 10*Approach Code

2 TCODE(C) I Table Code = 81

3 ELTYPE(C) I Element type



6 UNDEF(4) None





10 NUMWPE I Number of words per element

11 UNDEF(40) None




Record - DATA


1 EID I Element id*10+device code

2 CTYPE CHAR4 GRID or GAUS


4 GV RS Opening gap value of grid

Words 3 and 4 repeat 3 times.






















Record - TRAILER


1 UNDEF(6 ) None

OCPSDFC

Table of cross-power spectral density functions for composites.

Record 0 – HEADER



Record 1 – IDENT



2 TCODE(C) I Table code; always 4100

3 UNDEF none

4 RANDID I RANDOM set identification number

5 DCODE I Device code +10*function number

6 RCROSSID I RCROSS identification number


8 UNDEF none





9 FCODE I Format code


11 RTYPE1 CHAR4 Type of first response quantity

12 ID1 I Element, grid or scalar point ID number



15 RTYPE2 CHAR4 Type of second response quantity

16 ID2 I Element, grid, or scalar point ID number



19 CURID I Curve ID number

20 UNDEF(31) none




Record 2 – DATA



2 CPSDFR RS Real part of cross-power spectral density functionvalue

3 CPSDFI RS Imaginary part of cross-power spectral densityfunction value

Record 3 – TRAILER


1 WORD1 I Number of records

2 WORD2 I Number of data values in record 2.





3 UNDEF(4) none

ODAMGCZD

Table of damage value for cohesive element for SOL 401

Damage values at corner grids on bottom, and the values are unitless.

Record - HEADER





Record - IDENT


1 ACODE I Device code + 10*Approach code = 60 +iand (print, plot)

2 TCODE I Table code

3 ELTYPE(C) I Element type number

4 SUBCASE I Subcase number


6 UNDEF(45) None




Record - DATA


1 EID I Element ID * 10 + device code





2 DMID I Damage model ID:

• 1 = POLYNOMIAL

• 2 = BITRIANGULAR

• 3 = EXPONENTIAL

3 NVPG I Number of grid/damage values, =3 forPOLYNOMIAL, BITRANGULAR, EXPONENTIAL


5 DV1 RS Damage value d1



Repeat word 4-7 for each corner grid point. (8 corners for cohesive CHEXA (CHEXCZ) and 6corners for cohesive PENTA element (CPENTCZ).)

Record - TRAILER


1 UNDEF(6) None

ODAMGCZR

Table of relative displacements for cohesive elements for SOL 401

Relative displacements at corner grids on bottom, and the unit is length

Record - HEADER








Record - IDENT







6 UNDEF(4) None

10 NWDSPE I Number of words per element

11 UNDEF(40) None




Record - DATA



2 GRID I External identification number of grid

3 RDN RS Normal relative separation

4 RD1 RS In-plane relative motion in X direction (Basic C.S.)

5 RD2 RS In-plane relative motion in Y direction (Basic C.S.)

6 RD3 RS In-plane relative motion in Z direction (Basic C.S.)


Record - TRAILER


1 UNDEF(6) None




ODAMGCZT

Table of tractions for cohesive element for SOL 401

Tractions at corner grids on bottom, and the unit is force/length^2

Record - HEADER





Record - IDENT







6 UNDEF(4) None

10 NWDSPE I Number of words per element

11 UNDEF(40) None




Record - DATA



2 GRID I External identification number of grid

3 TN RS Normal stress on face





4 T1 RS Shear stress on face in X direction (Basic C.S.)

5 T2 RS Shear stress on face in Y direction (Basic C.S.)

6 T3 RS Shear stress on face in Z direction (Basic C.S.)


Record - TRAILER


1 UNDEF(6) None

ODAMGPFD

Table of damage values for ply failure for SOL 401

Damage values at corner grids on middle, and the values are unitless.

Record - HEADER





Record - IDENT







6 UNDEF(4) None

10 NUMWDE I Number of words per entry in DATA record





11 UNDEF(40) None




Record - DATA


1 ELID I Element ID * 10 + device code


3 DMID I Damage model ID (1-UD)

4 NVPG I Number of active damage values, =6 for UD model








On each ply, words 5-11 repeat for each corner grid point. (4 corners for composite HEXA(CHEXAL) and 3 corners for composite PENTA element (CPENTAL).)

Record - TRAILER


1 UNDEF(6) None

ODAMGPFE

Table of damage energy for ply failure for SOL 401

The energy dissipated due to damage for the whole element across all plies; and the unit is force *length




Record - HEADER





Record - IDENT




3 ELTYPE I Element type number



6 UNDEF(4) None

10 NWDSPE I Number of words per element = 2

11 UNDEF(40) None




Record - DATA



2 DENG RS Damage energy

Record - TRAILER


1 UNDEF(6) None




ODAMGPFS

Table of damage for SOL 401

Damage status for the whole element across all plies.

A scalar of:

• 0 = None.

• 1 = Partial damage (some plies have some damage).

• 2 = Ply failure (some plies have completely failed).

• 3 = Complete failure (all plies have failed).

Note

• Within a ply, if the worst damage value reaches 1.0 on a Gauss point, it means thatthis ply has damage.

• If the worst damage value reaches 1.0 on all Gauss points, it means that this ply hascompletely failed.

• The values are unitless.

Record - HEADER





Record - IDENT




3 ELTYPE I Element type number



6 UNDEF(4) None





10 NWDSPE I Number of words per element = 2

11 UNDEF(40) None




Record - DATA



2 DMGS I Damage status:

• 0 = None

• 1 = Partial

• 2 = Ply failed

• 3 = Laminate failed

Record - TRAILER


1 UNDEF(6) None

OUMAT

Table of state variables

Record – HEADER


1 NAME(2) CHAR4 Data block Name

3 WORD I No Def or Month, Year, One, One





Record – IDENT


1 ACODE(C) I Device code + 10*Approach Code

2 TCODE(C) I Table Code

3 ELTYPE(C) I Element Type

4 SUBCASE I Subcase ID

5 TIME RS Time step

6 UNDEF(4) None

10 NUMWDE I Number of grids written to the DATA record

11 GGOPT I Grid/Gauss option: =0 for grid; =1 for Gauss

12 UNDEF(39) None




Record – DATA


1 ELTYPE I Element type


ELTYPE = 39 CTETRA

2 EID I Element ID

3 MATID I Material ID

4 NVPG I Number of values per grid or Gauss point

5 GRID I Grid or Gauss point

6 SVI I State variable index

7 SVV RS State variable value


Words 5 through 7 repeat 4 times





ELTYPE = 67 CHEXA

2 EID I Element ID









ELTYPE = 68 CPENTA

2 EID I Element ID









ELTYPE = 255 CPYRAM

2 EID I Element ID













ELTYPE = 242 CTRIAX3

2 EID I Element ID









ELTYPE = 243 CQUADX4

2 EID I Element ID









ELTYPE = 244 CTRIAX6





2 EID I Element ID









ELTYPE = 245 CQUADX8

2 EID I Element ID









ELTYPE = 271 CPLSTN3

2 EID I Element ID














2 EID I Element ID










2 EID I Element ID










2 EID I Element ID













ELTYPE = 275 CPLSTS3

2 EID I Element ID










2 EID I Element ID














2 EID I Element ID










2 EID I Element ID









ELTYPE = 324 CGPLSTN3

2 EID I Element ID














2 EID I Element ID










2 EID I Element ID













2 EID I Element ID









ELTYPE = 337 CCHOCK3

2 EID I Element ID










2 EID I Element ID














2 EID I Element ID










2 EID I Element ID











Record – TRAILER


1 UNDEF(6) None

Updated modules

ACMG

Updated Format:

ACMG PANSLT,BGPDT,CSTM,SIL,ECT,EQACST,NORTAB,EQEXIN,EDT,GEOM2,CASECC/{AGG or APART},OACCQ/LUSET/MPNFLG/NUMPAN/S,N,PANAME/IPANEL/MATCH/PNLPTV $

New Input Data Block:

CASECC Table of case control values

New Output Data Block:

OACCQ Acoustic coupling quality values

CASE

Updated Format 1:

CASE CASECC,PSDL/CASEXX/APP/S,N,NSKIP/S,N,NOLOOP/S,N,LINC/GMAFLG/S,N,MSCHG/S,N,TESTNEG/S,N,IMETHOD/CASCOM1/CASCOM2/CASCOM3/CASCOM4/CASCOM5/CASCOM6/CASCOM7/CASCOM8/CASCOM9/CASCOM10/CASCOM11/CASCOM12/CASCOM13/CASCOM14/CASCOM15 $

Updated Format 2:

CASE CASECC,MPT/CASEXX/APP/S,N,NSKIP/S,N,NOLOOP/S,N,LINC/LGDISP/S,N,MSCHG/S,N,TESTNEG/S,N,IMETHOD/CASCOM1/CASCOM2/CASCOM3/CASCOM4/CASCOM5/CASCOM6/CASCOM7/CASCOM8/CASCOM9/CASCOM10/CASCOM11/CASCOM12/CASCOM13/CASCOM14/CASCOM15 $




CNTMAPTR

Updated Format:

CNTMAPTR CNELM,INPUT,UGCB,BGPDT/OUTPUT/IOPT/LGDISP $

Changed Input Data Block:

• The 2nd input data block changes from TFTRAC to INPUT.

New Input Data Blocks:

INPUT Input can be either tractions or slip at nodes per contact face/edge

UGCB Current displacements

BGPDT Basic grid point definition table

Changed Output Data Block:

• The 1st output data block changes from TLAMDA to OUTPUT.


OUTPUT Contact tractions or slip at new contact elements after geometry update

New Parameters:

IOPT Input-integer-no default.IOPT = -3 to map plastic slip onlyIOPT =1 to map tractionsIOPT = 2 (not used)IOPT = 3 to map elastic slip onlyIOPT = 4 (not used)

LGDISP Input-integer-no default. Large displacement flag

CNTSTAT

Updated Format:

CNTSTAT CNELM,ECSTAT,DLAMDA,TLAMDA,PLAMDA,UGCB,BGPDT,OFFSETP,ELSLIP/ECSTAT2,TLAMDAM/S,N,CITO/CNTNINC/S,N,NCS0/S,N,NCS1/S,N,NCS2/S,N,NCS3/S,N,NCSC/S,Y,GEOMUPDT/S,N,NOGSET/LGDISP/SEQDEPFL $

Changed Input Data Blocks:

• The 3rd input data block changes from ELAMDA to DLAMDA.




• The 5th input data block changes from ECDISP to PLAMDA.


DLAMDA Contact tractions (not used)

PLAMDA Contact tractions from prior step

OFFSETP Contact offsets from prior subcase

ELSLIP Contact element elastic slip

New Output Data Blocks:

TLAMDAM Updated total contact element tractions

Changed Parameters:

• The 2nd parameter changes from NOFAC to CNTNINC.

• The 8th input data block changes from INREL to GEOMUPDT.

New Parameters:

CNTNINC Input-integer-no default. Counter for number of time steps

GEOMUPDT Input-integer-no default. Geometry update flag

SEQDEPFL Input-integer-no default. Sequential dependence flag

CNTXTRAP

Updated Format:

CNTXTRAP CNELM,ECSTAT,INPUT/OUTPUT/IOPT $


• The 3rd input data block changes from TLAMDA to INPUT.


INPUT Contact tractions or penetration

Changed Output Data Block:

• The 1st output data block changes from TFTRAC to OUTPUT.





OUTPUT Extrapolated tractions or penetrations

New Parameter:

IOPT Input-integer-no default.IOPT = 1 for tractionsIOPT = 2 for penetrations

CONSTF

Updated Format:

CONSTF CNELM,BGPDT,CSTM,UGCB,ECSTAT,TLAMDA,UGCD,PLAMDA,ELSLIP/KELMC,KDICTC/GSIZE/LGDISP/IOPT/CNTNINC $


• The 7th input data block changes from ELAMBDA to UGCD.


UGCD Displacement increment from last step

PLAMDA Contact tractions from prior step

ELSLIP Contact element elastic slip

Changed Output Data Blocks:

• The 1st output data block changes from ELCNST to KELMC.

• The 2nd output data block changes from ELCTST to KDICTC.


KELMC Contact element matrix dictionary table

KDICTC Table of contact element matrices

New Parameter:

CNTNINC Input-integer-no default. Counter for number of time steps




CONTOUT

Updated Format:

CONTOUT CNELM,ECDISP,CASESX2H,ECSTAT,ECDISD,BGPDT,CNTPENTR,UGC,ISLIP,TFSLIP/OSPDS1,OSLIDE1,OCONST1/NVEC/DMAPNO/RSTIME/LGDISP $


UGC Current displacements

ISLIP Contact element incremental slip since last output time point

TFSLIP Nodal slip output by CNTSLIP module

DLT2SLT

Updated Format:

DLT2SLT DLT,SLT,DIT,EST/NEWSLT/DTIME/CASELOAD/CASEDLOD/S,N,NEWLOAD/LVAR/LOADPREV/START/END/NSTEP $

New Parameters:

LVAR Input-character-default=STEP. Specifies whether to step or ramp thetime-independent static load (specified on the LOAD case control) in the currentsubcase. Valid inputs are STEP and RAMP.

LOADPREV Input-integer-no default. LOAD SID from previous subcase. Set to 0 if thereis no LOAD in the previous subcase

START Input-real-no default. Start time of the current subcase

END Input-real-no default. End time of the current subcase

NSTEP Input-integer-no default. Number of time increments in the TSTEP1 bulk entryof the current subcase. This input is used for constant time subcases whenLVAR = RAMP only

New Remark:

1.

2.

3.




4. If LVAR=RAMP, the DLT2SLT module ramps only the static loads (LOAD case control) betweenthe end time of the previous subcase and the end of the current subcase. The equivalent staticload at the instant DTIME that are computed from time dependent loads (assigned using DLOAD)are added to the interpolated (RAMPED) static load.

DOM10

Updated Format:

DOM10 DESTAB,XINIT,X0,CNTABRG,CVALRG,CVALO,DVPTAB*,PROPI*,PROPO*,R1TABRG,R1VALRG,R1VALO,RSP2RG,R2VALRG,R2VALO,OPTPRMG,OBJTBG,DRSTBLG,TOL1,FOL1,FRQRPRG,DBMLIB,BCON0,BCONXI,WMID,RSP3RG,R3VALRG,R3VALO,EDT,HIS,SHELDT//DESCYCLE/DESMAX/OBJIN/OBJOUT/EIGNFREQ/PROTYP/RESTYP $


HIS Table of design iteration history.

SHELDT DVEREL1 bulk data specified shell elements information.

DOM12

Updated Format:

DOM12 XINIT,XO,CVAL,PROPI*,PROPO*,OPTPRM,HIS,DESTAB,GEOM1N,COORDO,EDOM,MTRAK,EPT,GEOM2,MPT,EPTTAB*,DVPTAB*,XVALP,GEOM1P,R1TABRG,R1VALRG,RSP2RG,R2VALRG,PCOMPT,OBJTBG,ALBULK,AMLIST,DIT,CNTABRG,SHELDT,CASEXX/HISADD,NEWPRM,DBCOPT,NEWDES,XNTSID,OSHT1/DESCYCLE/OBJIN/OBJOUT/S,N,CNVFLG/CVTYP/OPTEXIT/DESMAX/MDTRKFLG/DESPCH/DESPCH1/MODETRAK/EIGNFREQ/DSAPRT/PROTYP/BADMESH/XYUNIT/FSDCYC/S,N,FLGINT/POST $



CASEXX The main case control data block.


OSHT1 Output data block that goes in the OP2 file. It contains optimized thicknesses forDVEREL1 specified elements.




New Parameters:

POST The bulk data parameter POST, as in "PARAM, POST, -2" for example.

DOPR1

Updated Format:

DOPR1 EDOM,EPT,DEQATN,DEQIND,GEOM2,MPT,CASEXX,DIT,EDT,SHLLDT,ECT/DESTAB,XZ,DXDXI,DTB,DVPTAB*,EPTTAB*,CONSBL*,DPLDXI*,PLIST2*,XINIT,PROPI*,DSCREN,DTOS2J*,OPTPRM,CONS1T,DBMLIB,BCON0,BCONXI,DMATCK,DISTAB,CASETM,SPAN23,MFRDEP,DESVUP,EDOMNU,GEOM2N,ECTNU,EPTNU,SHELDT/S,N,MODEPT/S,N,MODGEOM2/S,N,MODMPT/DPEPS/S,N,PROTYP/S,N,DISVAR $


EDT Element data table.

SHLLDT Temporary data block which contains DVEREL1 bulk data supported shellelements information, when DVEREL1 data exists.

ECT Element connectivity table.


EDOMNU EDOM data block modified for DVEREL1 based SOL 200 run. To be copied toEDOM.

GEOM2N GEOM2 data block modified for DVEREL1 based SOL 200 run. To be copied toGEOM2.

ECTNU ECT data block modified for DVEREL1 based SOL 200 run. To be copied to ECT.

EPTNU EPT data block modified for DVEREL1 based SOL 200 run. To be copied to EPT.


DPD

Updated Input Data Block Description:

RCROSSL Table of RCROSS and RCROSSC Bulk Data entry images




ELTPRT

Updated Format:

ELTPRT ECT,GPECT,BGPDT,NSMEST,EST,CSTM,MPT,DIT,CASECC,EPT,COMPEST/VELEM,SHLLDT/PROUT/S,N,ERROR/WTMASS $


COMPEST Composite solid element summary table


SHLLDT Temporary data block to be later used for input to DOPR1 module call. It containsDVEREL1 bulk data supported shell elements information, when DVEREL1 dataexists.

EMG

Updated Format:

EMG EST,CSTM,MPT,DIT,CASECC,UG,ETT,EDT,DEQATN,DEQIND,BGPDT,GPSNT,ECTA,EPTA,EHTA,DITID,EBOLT,COMPEST,EFILL,PCOMPT,EPT/KELM,KDICT,MELM,MDICT,BELM,BDICT,ELMMOD,CONFAC2/S,N,NOKGG/S,N,NOMGG/S,N,NOBGG/S,N,NOK4GG/S,N,NONLHT/COUPMASS/TEMPSID/DEFRMSID/PENFAC/IGAPS/LUMPD/LUMPM/MATCPX/KDGEN/TABS/SIGMA/K6ROT/LANGLE/NOBKGG/ALTSHAPE/PEXIST/FREQTYP/FREQVAL/FREQWA/UNSYMF/S,N,BADMESH/DMGCHK/BOLTFACT/REDMAS/TORSIN/SHLDAMP/SHLDMP/BSHDMP/LMSTAT/LMDYN/STFOPTN/MODOPTN/HINDEX/HOOPDOF/ISPCSTR $

New Parameters:

HINDEX Input-integer-default=0. Harmonic index

HOOPDOF Input-integer-default=0. Flag indicating whether to include the additional hoopDOF in the formulation of axisymmetric elements in SOL 401 onlyHOOPDOF = 1 to include the additional hoop DOFHOOPDOF = 0 to not include the additional hoop DOF

ISPCSTR Input-integer-default=0. Controls the computation of structural and fluidelemental matricesISPCSTR = 0 to compute the structural and fluid elemental matricesISPCSTR = -1 to compute the structural elemental matrices onlyISPCSTR = 1 to compute the fluid elemental matrices only

New Remark:

1.




2.

3.

4. If system cell 617 (ACFORM) is set to 1, EMG computes the structural elemental matrices only.

EXTSEIDS

Updated Format:

EXTSEIDS TUG1,TQG1,TQMG1,TGPF,TES1,TEE1,TEF1,TES1C,TEE1C/SEGRD,SEELM


TES1C Table of ply stress elements for external partitioned superelement

TEE1C Table of ply strain elements for external partitioned superelement

FOCOEL

Updated Format:

FOCOEL CASECC,BGPDT,CSTM,GEOM2,EST,MPT,CONTACT,SIL,GPSNTC,UGCB,GEOM4,FEPEN,UGCP/CNELM,GPECTC,SPCCY/NSKIP/OPTION/NLHEAT/GSIZE/S,N,REFOPT/S,N,CNTSET/S,N,NCELS/S,N,MAXO/S,N,MAXI/CNTS/S,N,AITK/S,N,MPLI/S,N,RESET/S,N,FRICTM////S,N,CTOL/CNTLOOP/LGDISP/S,N,NSEGCYC/S,N,CYCAXID/FSYMTOL $


• The 10th input data block changes from UG to UGCB.


UGCB Displacements from current time step in basic coordinate system

GEOM4 Table of Bulk Data entry images related to constraints, DOF membership, andrigid element connectivity

FEPEN Maximum penetrations on each element face/edge that is involved in the contactdefinition

UGCP Displacements from prior time step in basic coordinate system


SPCCY Table containing constraint equations generated for cyclic solution, dependentand independent DOF SILs, and filtered SPC constraints for cyclic solution. (Onlyoutput for SOL 401 cyclic solution.)




Changed Parameters:

• The 4th parameter changes from MEL to GSIZE.

• The 14th parameter changes from CTOL to FRICTM.

• The 15th parameter changes from CNTLOOP to UNUSED.

New Parameters:

GSIZE Output-integer-no default. Size of the g-set array

FRICTM Output-real-no default. Maximum friction coefficient from all pairs

LGDISP Input-integer-no default. Large displacement flag

NSEGCYC Output-integer-no default. Represents total number of sectors from the fullgeometry. (Only output for SOL 401 cyclic solution.)

CYCAXID Output-integer-no default. Coordinate system identification number (CSID) forcyclic axis of symmetry. (Only output for SOL 401 cyclic solution.)

FSYMTOL Input-real-no default. Value of FSYMTOL that is specified on NLCNTL and is usedto determine whether unsymmetric stiffness is used for contact

FOELCS

Updated Format:

FOELCS CNELM,BGPDT,CSTM,ECSTAT,TLAMDA/ELCNST,ELCTSTS,N,NLHEAT/S,N,IMODE/K6ROT/CITO $

Removed Input Data Block:

USET Degree-of-freedom set membership table for g-set


ECSTAT Contact element status array

TLAMDA Total contact element tractions

New Parameter:

CITO Input-integer-no default. Contact outer loop ID




FOGLEL

Updated Format:

FOGLEL CASECC,BGPDT,CSTM,GEOM2,EST,MPT,CONTACT,SIL,GPSNTC,UNUSED/GNELM,GPECTC/NSKIP/OPTION/NLHEAT/GSIZE/S,N,REFOPT/S,N,GLUSET/S,N,NGELS $

Changed Parameter:

• The 4th parameter changes from MEL to GSIZE.

New Parameter:

GSIZE Input-integer-no default. Size of g-set.

GP4

Updated Format:

GP4 CASECC,GEOM4,EQEXIN,SIL,GPDT,BGPDT,CSTM,MEDGE,MFACE,MBODY,GEOM2,GDNTAB,GPECTO,DYNAMIC/RMG,YS0,USET0,PARTV/LUSET/S,N,NOMSET/S,N,MPCF2/S,N,NOSSET/S,N,NOOSET/S,N,NORSET/S,N,NSKIP/S,N,REPEAT/S,N,NOSET/S,N,NOL/S,N,NOA/SEID/ALTSHAPE/SEBULK/DMAPNO/AUTOMPC/AMPCZ/RSONLY/NLBEAR/SPCSTR $

New Parameter:

SPCSTR Input-character-default=NO. If SPCSTR=YES, the software to eliminates thestructural DOF from the analysis set. (See also the QRG description for theSPCSTR parameter.)

GP5

Updated Format:

GP5 ECT,BGPDT,EQEXIN,EDT,SIL,GEOM2/PANSLT,EQACST,NORTAB/S,N,MPNFLG/S,N,NUMPAN/S,N,MATCH/NASOUT/GETNUMPN/S,N,METHOD/S,N,SKINOUT/S,N,NORMAL/S,N,OVLPANG/S,N,INTOL/S,N,ABSFLG/S,N,NGAUSS/S,N,CTYPE $




New Parameter:

CTYPE Output-character-default=”STRONG”. Coupling type.

="STRONG" to include fluid pressure on structure

="WEAK" to ignore fluid pressure on structure

GPFDR

Updated Format:

GPFDR CASECC,UG,KELM,KDICT,ECT,EQEXIN,GPECT,PG,QG,BGPDT,{LAMA or FOL or TOL or OLF},CSTM,VELEM,PTELEM,QMG,NFDICT,FENL,MELM,MDICT,BELM,BDICT,MDLIST/ONRGY1,OGPFB1,OEKE1,OEDE1/APP/TINY/XFLAG/CYCLIC/WTMASS/S,N,NOSORT2/HINDEX/SCFLAG/CYC_SUBCAS $

New Parameters:

HINDEX Input-integer-default=0. Harmonic index

SCFLAG Input-integer-default=-1. Symmetric/anti-symmetric flag for SOL 401 cyclic modesand Fourier subcases only

-1 All other solution types

0 0th harmonic

1 Symmetric component

2 Anti-symmetric component

CYC_SUBCAS Input-integer-no default. Cyclic modes subcase ID for SOL 401

IFP1

Updated Format:

IFP1 /CASECC,PCDB,XYCDB,POSTCDB,FORCE,SETMC,JCASE/S,N,NOGOIFP1/S,N,LASTCC/S,N,BEGSUP/DMAPNO $


JCASE An unaltered, unsorted copy of user Case Control commands

New Remark:

1.

2.




3. JCASE is not generated unless defined in a DMAP sequence.

MATMOD

Updated Option P1=56

Updated Format:

MATMOD I1,,,,,,,,,,,,,,,/O1,/56/ICOL/IROW/TYPE/REAL//NCOL/NROW/INT/TFLAG///////REALD/CMPLX/CMPLXD$

Updated Parameters:

ICOL Column number for a matrix; record number for table.

IROW Row number for a matrix; word number for table.

TYPE Type of value to be replaced or added.

0 Replace current value with INT. (Table only)

1 Replace current value with REAL. (Table and matrix)

2 Replace current value with REALD. (Matrix only)

3 Replace current value with CMPLX. (Matrix only)

4 Replace current value with CMPLXD. (Matrix only)

-1 Add REAL to current value. (Matrix only)

-2 Add REALD to current value. (Matrix only)

-3 Add CMPLX to current value. (Matrix only)

-4 Add CMPLXD to current value. (Matrix only)

NCOL Number of columns in O1 if I1 is purged. (Matrix only)Default=ICOL.

NROW Number of rows in O1 if I1 is purged. (Matrix only) Default=IROW.

New Parameters:

INT Integer value. (Table only)

TFLAG Table flag. (Default = 0)

0 Matrix

1 Table




Updated Examples:

In matrix A, add 10.5 to the value of a32 (the element of the matrix at column 2 and row 3):MATMOD A,,,,,,,,,,,,,,,/A1,/56/2/3/—1/10.5 $

In table CASECC, overwrite word 163 in record 1:MATMOD CASECC,,,,,,,,,,,,,,,/CASECCX,/56/1/163/0/////100/1 $


Updated Format:

MATMOD ONRGY,EFILL,,,,,,,,,,,,,,/ELRSCALV,/58 $


ELRSCALV EFILL table in ELRSCALV format.

Updated Remark:

1. The normalized material density output data block (ELRSCALV) is used to store the element fill inratios in the case of topology optimization with the external optimizer. This enables the user tovisualize the optimized geometry without changing the OP2 file structure or introducing a newentity. This option is available beginning in Version 8.5.


Updated Format:

MATMOD GEOM2,EFILL,,,,,,,,,,,,,,/BEGCPL,BEGCID/59 $


BEGCID Matrix containing ndvar columns, where ndvar is the number of design variable ( =number of rows) in EFILL, and 20 rows. Each column contains the indices of theconnected grids. For example, in the case of Quad 4 and TET4 element, the first4 rows are the connected grid indices and the rest 16 rows are zeros.

Updated Remarks:

1. The ncgrid terms in each column of the output data block BEGCPL are either 1 or zero, indicatingwhether the element is connected to the grid corresponding to the row index or not.

2. Note that the element indices are not the external grid IDs.

New Option P1=60

Create an element matrix for the design variable elements contained in the EFILL matrix.




Format:

MATMOD ELEM,KDICT,EFILL,,,,,,,,,,,,,/ELEMDV,/60/ITOSIMP/P3/ITOSIMP1/ITOSIMP2 $

Input Data Blocks:

ELEM Element stiffness/mass matrix

KDICT Element stiffness/mass dictionary

EFILL Element fill in matrix

Output Data Block:

ELEMDV Element stiffness/mass matrix for the design variable elements contained in theEFILL matrix

Parameters:

ITOSIMP Input-integer-no default. Solid isotropic material with penalization (SIMP) methodoption, fiITOSIMP, where fi , i=1, …, ndvar are the efill ratios listed in EFILL matrix

P3 Input-integer-no default. Matrix typeP3 = 0 for element stiffness matrixP3 = 1 for element mass matrix

ITOSIMP1 Input-real-no default. Specifies a lower fill-in threshold above which the originalSIMP method is applied (fiITOSIMP). Below the ITOSIMP1 threshold a new SIMPmethod of form (fi / ITOSIMP2) applied. ITOSIMP2 is required.

ITOSIMP2 Input-real-no default. Specifies a factor used in SIMP method along withITOSIMP1

Examples:

To update element stiffness matrix for the design variable element in the EFILL matrix:

MATMOD KELM,KDICT,EFILL,,,,,,,,,,,,,/KELMDV,/60/ITOSIMP/0/ITOSIMP1/ITOSIMP2 $

To update element mass matrix for the design variable element in the EFILL matrix:

MATMOD MELM,MDICT,EFILL,,,,,,,,,,,,,/MELMDV,/60/1/1 $

New Option P1=61

Used internally for development.




New Option P1=62

Two output datablocks are produced. One contains the maximum absolute value for each columnover all the rows of a matrix. The other contains the row number where the maximum absolutevalue in each column occurs.

Format:

MATMOD UG,,,,,,,,,,,,,,,/UGMAX,ROWMAX/62 $

Input Data Block:

UG Matrix that contains the magnitudes of nodal displacements

Output Data Block:

UGMAX Matrix that contains the maximum absolute value in each of the columns of theUG matrix

ROWMAX Table that contains the row number where the UGMAX value occurs for eachcolumn

MODACC

New Format:

MODACC MDLIST,OL,U,P1,P2,P3/OL1,U1,P11,P21,P31/APP/IOPT $


• The 1st input data block changes from CASECC to MDLIST.


MDLIST Mode list from EFFMAS.




Updated Parameter:

IOPT Input-integer-default=0. Processing options:

0=process OFREQ or OTIME or OMODES.

1=process SETMC for MODCON.

2=process SETMC for PANCON.

3=process SETMC for ERP.

4=process MDLIST. Only valid if APP=‘REIGEN’.

NLTRD3

Updated Format:

NLTRD3 CASESX2H,PDT,YS,ELDATAH,KELMNL,KDDL,GMNL,MPTS,DITS,KBDD,DLT1,CSTMS,BGPDT,SILS,USETD,UNUSED,MJJ,NLFT,UNUSED,UNUSED,UNUSED,GPSNTS,DITID,DEQIND,DEQATN,ELGNST,GLUESEQ,COMPEST,KDICTUP,EPT,ECTS,EDT,RGNL,UNUSED,SLT,KELMUP,GEOM3,GEOM5,ETT,FBSIN,CNELM,ECSTAT,ESLIP,TLAMDA,PLAMDA,EST,GPECT,INITGAUS,UGCPREV,YS1I,ECDISPG,DLT,KDICTNL,CONFAC2,GEOM1,GEOM2,PVT0,SETMC,OFFSETP,RFRCEI,PSLIP,DLT2,PGT/ULNTH,IFSH,ESTNLH,IFDH,OES1,PNLH,TELH,MULNT,MESTNL,MESTNL2,UNUSED,PBDATA,OSTR1,OSTR1EL,OSTR1TH,OSTR1PL,OSTR1CR,OES1G,OSTR1G,OSTR1ELG,OSTR1THG,OSTR1PLG,OSTR1CRG,OTEMP1,OES1C,OSTR1C,OSTR1ELC,OSTR1THC,OQGGF1,OBG1,PLPG,FENLR,PLFG,UGLAST,FBSOUT,TLAMUP,ADGPECT,ADEST,ADSTRES,OERRES,OERREP,OERRSS,OERRSP,CNELMUP,OJINT,UNUSED,ELAMUP,YS2F,UDLAST,ESTNLINI,CSDATA,PBDATA,OJINE,CNTPENTR,UMATINL,STATVAR2,OUMAT,OUMATG,ODAMGPFD,ODAMGPFE,ODAMGPFS,ODAMGCZT,ODAMGCZR,ODAMGCZD,OCKGAP1,OCKGAP1G,OBOLT1,UGGPO,OSLIDEG1,DLAMDA,OSTR1PLC,RFRCEF,ECSTATUP,TSLIP,PLPG2/KRATIO/S,N,CONV/S,N,RSTIME/S,N,NEWP/S,N,NEWDT/S,N,OLDDT/S,N,NSTEP/LGDISP/S,N,ANAL/S,N,ITERID/ITIME/S,N,KTIME/S,N,LASTUPD/S,N,NOGONL/S,N,NBIS/MAXLP/TSTATIC/LANGLE/NDAMP/TABS/UNUSED/MATNL/S,N,UNUSED/ITERMP/0/GLUE/GPFORCE/BCSET/S,N,CITO/S,N,CITI/AUGLOOP/S,N,CNVO/S,N,CNTPUPDT/S,N,CONFLAG/CNTNINC/S,N,BISFLAG/S,N,DTLAST/S,N,CPLFLG/S,N,PBCONV/S,N,CNTUPDT/NCELS/S,N,CRPFLAG/S,N,COUNT/S,N,MESTFLG/RSTMPREV/ENDTIME/S,N,CNTNDIV $

Changed Input Data Blocks:

• The 16th input data block changes from BRDD to UNUSED.

• The 21st input data block changes from BDDL to UNUSED.

• The 43rd input data block changes from ELAMDA to ELSLIP.




• The 44th input data block changes from UNUSED to TLAMDA.

• The 48th input data block changes from UNUSED to INITGAUS.

• The 49th input data block changes from UGCPREV to UGCP.


ELSLIP Elastic slip that corresponds to the last time step

TLAMDA Current total contact tractions

INITGAUS Initial strains at all Gauss points in the basic coordinate system

UGCP Global displacements that correspond to the last time step

PVT0 Table of user parameter values

SETMC Table of set definitions for modal contributions

OFFSETP Contact face/edge region offsets from prior subcase

RFRCEI 2g-size array containing rpm and angular acceleration value at each grid at lastconverged time step

PSLIP Contact element slip from prior time step

DLT2 Dynamic load table that contains structural loads only for multiphysics

PGT Time-dependent load vectors for quasi-static analysis in the g-set

Changed Output Data Blocks:

• The 10th output data block changes from UNUSED to MESTNL2.

• The 12th output data block changes from UNUSED to PBDATA.

• The 56th output data block changes from ECSTATUP to UNUSED.

• The 62nd output data block changes from PBDATA to PBCHEK.


MESTNL2 Nonlinear element summary table at current step

PBDATA Table of the last converged bolt load and strain data from the previous subcase

PBCHEK Table of the last converged bolt load and strain data from the current subcase

UMATINL Table of state variables for user-defined material model NXUMAT

STATVAR2 Table of state variables for user-defined material model NXUMAT




OUMAT Table of state variable output for Gauss points

OUMATG Table of state variable output for grid points

ODAMGPFD Table of damage values for ply failure

ODAMGPFE Table of damage energy for ply failure

ODAMGPFS Table of damage status for ply failure

ODAMGCZT Table of tractions for cohesive elements

ODAMGCZR Table of relative displacements for cohesive elements

ODAMGCZD Table of damage values for cohesive elements

OCKGAP1 Table of opening gap values for chocking elements

OCKGAP1G Table of opening gap values at Gauss points for chocking elements

OBOLT1 Bolt output data block

UGGPO Global displacements from the last output request

OSLIDEG1 Glue slide distance output

DLAMDA Not used

OSTR1PLC Table of ply strains-plastic in SORT1 format

RFRCEF 2g-size array containing rpm and angular acceleration value at each grid atconverged time step upon exiting NLTRD3

ECSTATUP Updated contact element status

TSLIP Current total contact element slip

PLPG2 Matrix of load vectors (P external + P follower force). Unlike PLPG, the loadsin the constrained grids are included

Changed Parameters:

• The 24th parameter changes from UNUSED to ITERMP.

• The 25th parameter changes from UNUSED to 0.

• The 31st parameter changes from MAXI to AUGLOOP.

• The 33rd parameter changes from CNVI to CNTPUPDT.

• The 35th parameter changes from MINILP to CNTNINC.




New Parameters:

ANAL Input-integer-default=0. Flag that indicates the analysis type

1 for ANALYSIS = STATICS

2 for ANALYSIS = MODES

3 for ANALYSIS = PRELOAD

ITERMP Input-integer-default=0. Multiphysics iteration number

AUGLOOP Input/output-integer-default=0. Contact augmentation loop number

CNTPUPDT Input/output-integer-default=0. Number of contact pairing updates

CNTNINC Input/output-integer-default=0. Number of increments since the start of thesolution

MESTFLG Output-integer-default=1

1 Use MESTNL as the updated nonlinear element summary table

2 Use MESTNL2 as the updated nonlinear element summary table

RSTMPREV Input-real-default=0.0. End time of previous subcase

ENDTIME Input-real-no default. End time of current subcase

CNTNDIV Input/output-integer-no default. Number of contact-triggered divergences

OPRESSDB

Updated Format:

OPRESSDB CASECC,GEOM3PLD0,GEOM3PLD,TELH,ECTS/OPRESS/STIME/ETIME/LVAR $


ECTS Element connectivity table




OUTPRT

Updated Output Data Block:

TEXTOU Modified directory table for external superelement. Created if TEXTSE exists,MCFLAG=2, and IRTYPE=9, 10, or 11, or in the context of extended acoustics, ifTEXTSE does not exist and there are microphone points in the model. For theextended acoustics case, TEXTOU is a real single-precision 2 column matrix ofmicrophone point internal IDs and SIL numbers.

Updated Remark:

1.

2.

3. If TEXTSE is present, MCFLAG=2, and IRTYPE=9, 10, or 11, TEXTOU is created. The values ofIRTYPE and MATTYP must be consistent with the type of data contained in the TEXTSE datablock. In the context of extended acoustics, if TEXTSE is not present and there are microphonepoints in the model, TEXTOU is created as a real single-precision 2 column matrix of microphonepoint internal IDs and SIL numbers.

OUTPUT2

Updated Format:

OUTPUT2 DB1,DB2,DB3,DB4,DB5//ITAPE/IUNIT/LABL/MAXR/NDDLNAM1/NDDLNAM2/NDDLNAM3/NDDLNAM4/NDDLNAM5/HNAME1/HNAME2/HNAME3/HNAME4/HNAME5/ICONV $

New Parameter:

ICONV Input-integer-default=2. ICONV selects conversion of 64-bit files to 32-bit asfollows:

0 Do not convert to 32-bit

1 Force conversion to 32-bit

2 Use internal rules (parameters OP2FMT, POST, etc.) to determineconversion as documented in the Installation and Operations Guide

New Remark:

1.

2.

3.

4.




5.

6.

7.

8.

9.

10.

11.

12.

13. Consult the Installation and Operations Guide on the rules for conversion of OUTPUT2 files whenthe parameters OP2FMT and POST are present. Use of the ICONV parameter permits the userto override those rules for the specific file(s) named on the given OUTPUT2 request, whileleaving the other rules in place for all other OUTPUT2 requests.

RANDOM

Updated Input Data Block Description:

RCROSSL Table of RCROSS and RCROSSC Bulk Data entry images

ROTCZG

Updated Description:

Calculates the mass, Coriolis, and centrifugal matrices in a coupled rotor-support system of sizeg-set, when the IREFS parameter is set to 3.

New Format for coupled rotor-support system (IREFS = 3):

ROTCZG USGRD,MGG,BGPDTS,MGGDI,XYZ/MRGG,CRGG,ZRGG,BOOL/IREFS/NGSET/GRIDNUM/INEMETH $


USGRD Coupled grid points set.

MGG Full g-size mass matrix.

BGPDTS Basic grid point definition table.

MGGDI Diagonal mass matrix input as vector.

XYZ g-set by 3 matrix of x,y,z coordinates transformed to the rotor system.





MRGG Coupling mass matrix of size g-set containing the time dependent terms.

CRGG Coupling Coriolis matrix of size g-set containing the time dependent terms.

ZRGG Coupling centrifugal matrix of size g-set containing the time dependent terms.

BOOL Boolean matrix of size g-set containing coupling relationship.

New Parameters:

IREFS Reference system (3: coupled solution).

NGSET Number of g-size grids.

GRIDNUM Coupling grid ID between the rotor and support.

INEMETH Flag to include inertia terms in the coupling matrices.

SDR2

Updated Format:

SDR2 CASECC,CSTM,MPT,DIT,EQEXIN,SILD,ETT,{OL or EDT},BGPDT,PG,QG,UG,EST,XYCDB,OINT,PELSET,VIEWTB,GPSNT,DEQATN,DEQIND,DITID,PCOMPT,GPKE,BOLTFOR,MDLIST,COMPEST,EPT,DYNAMIC,EDT,CBRROT/OPG1,OQG1,OUG1,OES1,OEF1,PUG,OGPKE1,OEFIIP,OEFIIS,OESRIP,OESRIS/APP/S,N,NOSORT2/NOCOMP/ACOUSTIC/METRIK/ISOFLG/GPF/ACOUT/PREFDB/TABS/SIGMA/ADPTINDX/ADPTEXIT/BSKIP/FREQW/BTBRS/LANGLE/OMID/SRCOMPS/APP1/GSPF/RPM/SWPANGLE/STFOPTN/RUNIT/HINDEX/HOOPDOF/SCFLAG/CYCAXID/NACEXTRA $

New Parameters:

HINDEX Input-integer-default=0. Harmonic index.

HOOPDOF Input-integer-default=0. Flag indicating whether hoop DOF are present in theaxisymmetric elements.

SCFLAG Input-integer-default=-1. Symmetric/anti-symmetric flag.SCFLAG = -1 for other solution type outputSCFLAG = 0 for 0th harmonicSCFLAG = 1 for symmetric componentSCFLAG = 2 for anti-symmetric component

CYCAXID Input-integer-default=0. Identification number of the default cylindrical coordinatesystem for SOL 401 cyclic solution.

NACEXTRA Input-integer-default=0. Number of extra acoustic DOF.




TOPOPT

Updated Format:

TOPOPT EFILL,OBJMA,SENSMA,DVARMA,WMEMIN,FORCEM,BEGCM,SENSMK,UTIND/EFILLI,WMEMOUT,/ITOITCNT/ITOMXITR/ITOPOPT/ITOOPITR/S,Y,DONE/ITODENS/ITOSIMP/ITORMAS/ITONGHBR/ITOPDIAG/ITOPALG/ITOPCONV/ITOSIMP1/ITOSIMP2/MXDVCH $


SENSMK Kinetic energy matrix

UTIND Initial mass impact matrix for gravity load case

Changed Parameter:

• The 13th parameter changes from ITOPALLR to ITOSIMP1.

New Parameters:

ITOSIMP1 Input-real-default=0.0. Specifies a lower fill-in threshold above which the originalSIMP method is applied (fiITOSIMP). Below the ITOSIMP1 threshold a new SIMPmethod of form (fi / ITOSIMP2) applied. ITOSIMP2 is required.

ITOSIMP2 Input-real-default=0.0. Specifies a factor used in SIMP method along withITOSIMP1

MXDVCH Output-real-no default. The maximum design variable change

UPGLSTF

Updated Format:

UPGLSTF GNELM,BGPDT,CSTM,UGVBAS/ELGNST/IOPT/NROW/K6ROT $

Changed Parameter:

• The 1st parameter changes from NLHEAT to IOPT.

New Parameter:

IOPT Input-integer-no default. Analysis typeIOPT = 1 for ANALYSIS = STATICSIOPT = 2 for ANALYSIS = MODES or CYCLICIOPT = 3 for ANALYSIS = FOURIER




VDRMC

Updated Format:

VDRMC CASEG,SETMC,AMC,NMC,MAG,APC,NPC,PNLLST,OL,MFRQ,ECT,BGPDT,TEXTSE/OUTFLE/APP/S,N,NOSORT2/S,N,NOSOUT/FMODE/IRTYPE/FSFLAG/FS $

New Parameter:

FS Input-integer-default=0. Secondary fluid-structure flag. Only applies to IRTYPEs = 1thru 3.0 = structure only model1 = fluid only model2 = fluid and structure model

New modules

CNTSLIP

Compute total slip at end of each increment.

Format:

CNTSLIP CNELM,ECDISP,CASESX2H,ECSTAT,ECDISD,BGPDT,TSLIP,UGC,ISLIP,NODTRAK/TFSLIP/NVEC/DMAPNO/RSTIME/LGDISP $

Input Data Blocks:

CNELM Contact element definition table

ECDISP Contact element displacements at requested output time interval

CASESX2H Case control for current subcase

ECSTAT Contact element status table

ECDISD Contact element displacements from last output time interval


TSLIP Contact element total slip

UGC Current displacements

ISLIP Contact element incremental slip since last output time point




NODTRAK Nodal pressures and tractions output by FONOTR modules

Output Data Block:

TFSLIP Nodal slip containing elastic, plastic and total slip at each contact node

Parameters:

NVEC Input-integer-no default. Number of solution results to process

DMAPNO Input-integer-no default. DMAP number

RSTIME Input-real-no default. Current output interval time

LGDISP Input-integer-default=-1. Large displacement flagLGDISP = -1 to not consider large displacement effectsLGDISP = 1 to consider large displacement effects

CYC_MPC

Computes the constraint equations based on the harmonic index for cyclic solution in SOL401. Alsoused to modify USET, SIL and GEOM4 matrices based on cyclic harmonic index in a cyclic modalsolution. Applicable to quasi-static cyclic solution and normal modes solution at the 0th harmonic andfor cyclic modes solution at all allowed harmonic indices.

Format:

CYC_MPC CASESX2H,SPCCY,GEOM4I,USETI,UGI,CYCMPCI,QMGI,SILS,USR_MPCI,BGPDT,GPECT,CSTM,DYNAMICS/CASECY,GEOM4O,USETCY,RGNLCY,UGO,CYCMPCO,QMGO,CYCFORO,SILCY,USR_MPCO,DYNCYCL/S,N,CYCFLG/S,N,HINDEX/S,N,NSEGCYC/CYCAXID/S,N,ANA $

Input Data Blocks:

CASESX2H Table of case control command images for current subcase

SPCCY Table generated by FOCOEL that contains constraint equations, dependent andindependent DOF SILs, and filtered SPC constraints for cyclic solutions

GEOM4I Table of bulk data entries related to constraints

USETI DOF set membership table

UGI Harmonic modal solution matrix

CYCMPCI Table that contains SIL numbers for dependent and independent DOF for thegrids on cyclic faces




QMGI Table of MPC forces that contains user-defined MPCs and cyclic MPCs

SILS Original scalar index list

USR_MPCI Table that contains information related to user defined MPCs


GPECT Grid point element connections table

CSTM Table of coordinate system transformation matrices

DYNAMICS Table of bulk data entry images related to dynamics

Output Data Blocks:

CASECY Modified table of case control command images for current subcase toaccommodate additional SPCs associated with shared nodes on cyclic faces

GEOM4O Modified table of bulk data entries related to constraints, with constraints on gridsbelonging to the cyclic target face filtered

USETCY Updated DOF set membership table with cyclic MPCs accounted for. USETO isalso modified based on the harmonic index

RGNLCY Matrix for MPC equations which includes user-defined MPCs and cyclic generatedMPCs. RGNLO changes based on the harmonic index

UGO Diagonal matrix with complex eigenvalues on the diagonal. See Remark 8.

CYCMPCO Matrix obtained by splitting UGI into cosine and sine components

QMGO Table of MPC forces that correspond to user-defined MPCs only

CYCFORO Table of MPC forces that correspond to cyclic MPCs

SILCY Scalar index list modified based on harmonic index

USR_MPCO Table that contains information related to user-defined MPCs

DYNCYCL Modified table of bulk data entry images related to dynamics. Images related toEIGRL card are modified based on the harmonic index

Parameters:

CYCFLG Input-integer-no default. Flag that controls the operations of CYC_MPC




1 Scan MPC/SPC records from GEOM4I and filter any MPCs/SPCson cyclic target faces. For any additional SPC constraints that aregenerated by the cyclic solution, the case control table is modifiedand the output data blocks CASECY, GEOM4O, CYCMPCO, andUSR_MPCO are generated.

2 For each harmonic, compute the RGNLCY data block.

3 During data recovery, convert input data block UGI to output datablock UGO with separate cosine and sine components.

4 Split the QMGI input data block into two output data blocks: QMGOand CYCFORO.

5 Similar to CYCFLG=3, except the input data block UGI is adisplacement solution

6 Convert the Fourier mode vectors to physical eigenvectors during AFnormalization (UGI is input and UGO is output).

HINDEX Input-integer-no default. Value of harmonic index

NSEGCYC Input-integer-no default. Represents the total number of sectors from the fullgeometry

CYCAXID Input-integer-no default. Coordinate system identification number (CSID) forcyclic axis of symmetry

ANA Input-character-no default. Corresponds to the analysis type defined by theANALYSIS command in the subcase case control section

EMAAC

Calculates and assembles global g-set size (or modified g-set to account for extra AML DOF) acousticstiffness, mass, and damping matrices. Computes the global acoustic mass, stiffness and dampingmatrices. Requires that the GPAC module is called first.

Format:

EMAAC /KGGF,K4GGF,MGGF,BGGF/S,N,NOKGGF/S,N,NOK4GGF/S,N,NOMGGF/S,N,NOBGGF/FREQ/LUSET

Input Data Blocks:

None




Output Data Blocks:

KGGF Acoustic stiffness matrix in g-set size

K4GGF Acoustic damping matrix in g-set size

MGGF Acoustic mass matrix in g-set size

BGGF Acoustic viscous damping matrix in g-set size

Parameters:

NOKGGF Input/output-integer-default=-1. KGGF generation flag

Input:

= 0 Do not generate

≠ 0 Generate

Output:

= -1 Not generated

≠ -1 Generated

NOK4GGF Input/output-integer-default=-1. Same as NOKGGF

NOMGGF Input/output-integer-default=-1. Same as NOKGGF

NOBGGF Input/output-integer-default=-1. Same as NOKGGF

FREQ Input-real-default=0.0. The frequency at which the global acoustic mass,stiffness, and damping matrices are calculated

LUSET Input-integer-default=0. Number of DOF in the g-set

GPAC

Processes geometry and element information for extended acoustics formulation. This modulegenerates extra scalar DOF if AML regions are present in the model. The module also generatesmodified tables to account for the extra AML DOF.

Format:

GPAC EQEXIN,BGPDT,GEOM1,SIL,EPT,ECT,MPT,CONTACT,VGF,GPL,GPDT,DIT/VGFO,SILO,EQEXINO,BGPDTO,GPLO,GPDTO,VGFDAML,VGFCG/LUSET/S,N,AMLDOF/SEID/REENTRY $




Input Data Blocks:

EQEXIN Equivalence table between external and internal grid/scalar identification numbers


GEOM1 Table of Bulk Data entry images related to geometry

SIL Scalar index list

EPT Element property table

ECT Element connectivity table

MPT Table of Bulk Data entry images related to material properties

CONTACT Table of Bulk Data entry related to surface contact

VGF Fluid/structure partitioning vector

GPL Grid point list

GPDT Grid point definition table

DIT Direct input tables

CSTM Table of coordinate system transformation matrices

Output Data Blocks:

VGFO Updated fluid/structure partitioning vector

SILO Updated scalar index list if AML DOF exist

EQEXINO Updated equivalence table between external and internal grid/scalar identificationnumbers if AML DOF exist

BGPDTO Updated basic grid point definition table if AML DOF exist

GPLO Updated grid point list if AML DOF exist

GPDTO Updated grid point definition table if AML DOF exist

VGFDAML Partitioning vector with ones at rows corresponding to DOF of AML andthe acoustic elements attached to AML. The AML DOF are by definitionfrequency-dependent.

VGFCG Partitioning vector with ones at rows corresponding to DOF that connect to fluidelements and AML DOF




Parameters:

LUSET Input-integer-default=0. The number of DOF in the g-set

AMLDOF Input/Output-integer-default=0. The number of AML DOF

SEID Input-integer-default=-1. The superelement identification number

= -1 The full structure

= 0 The residual structure

> 0 The superelement identification number

REENTRY Input-integer-default=0

= 0 The first entry

= 1 The reentry

Remarks:

1. If there are no AML regions, the following input data blocks are optional: GPL, GPDT andCONTACT.

2. If there are no AML regions, the output blocks VGFO, SILO, EQEXINO, BGPDTO, GPLO,GPDTO and VGFDAML are all purged.

3. If it is the first entry (reentry = 0), VGFO, SILO, EQEXINO, BGPDTO, GPLO, GPDTO andVGFDAML are created if AML exists. For reentry (reentry = 1), only VGFDAML is created andVGFCG is updated.

INITOES

Creates output OES tables for initial strain at grids of elements and corner Gauss points from initialstrain tables that are generated by the INITSNCR module.

Format:

INITOES CASECC,ESTNLH,BGPDTS,SILS,CSTMS,INITGAUC,INITNODE/OSTR1IN,OSTR1ING/S,N,ERROFPIN/-1 $

Input Data Blocks:

CASECC Table of Case Control command images. The INITS case control settings areread from this data block.

ESTNLH Element summary table

BGPDTS Basic grid point definition table




SILS Scalar node index list

CSTMS Coordinate system table to compute coordinate system transformation

INITGAUC Table of initial strains at corner Gauss points in the basic coordinate systemcomputed using the INITSNCR module

INITNODE Table of initial strains at corner grids in the basic coordinate system computedusing the INITSNCR module

Output Data Blocks:

OSTR1IN OES output table of initial strains at corner grids in the basic coordinate system

OSTR1ING OES output table of initial strains at corner Gauss points in the basic coordinatesystem

Parameters:

ERROFPIN Output-integer-no default. Error code that indicates execution failure

= 0 No error

≠ 0 Indicates execution failure

Remarks:

1. The CASECC entries must correspond to the subcase of interest.

2. Because initial strains are computed before the start of the actual solve (before processingany subcases), the subcase ID and the solution time in the output OES data block is set to 0and 0.0, respectively.

3. The EPSTYPE(C) field in the OES data block header is set to initial strain (type=5).

INITSNCR

Generates tables for initial strain at nodes of element and element Gauss points in basic coordinatesystem from INITS bulk entries stored in GEOM3.

Format:

INITSNCR CASECC,GEOM3,ESTNLH,BGPDTS,GPECT,SILS,CSTMS,MPTS,DITS/INITNODE,INITGAUS,INITGAUC,UNUSED/S,N,ERRINICR/-1 $

Input Data Blocks:

CASECC Table of Case Control command images. The INITS case control settings areread from this data block.




GEOM3 Table of bulk data entry images for static and thermal loads. This module readsthe entries for initial stress/stain (INITS) from this data block.

ESTNLH Element summary table

BGPDTS Basic grid point definition table

GPECT Grid point element connection table

SILS Scalar node index list

CSTMS Coordinate system table to compute coordinate system transformation

MPTS Table of bulk data images for material properties

DITS Table of TABLEij bulk data images

Output Data Blocks:

INITNODE Initial strains at corner grids in the basic coordinate system

INITGAUS Initial strains at all Gauss points in the basic coordinate system

INITGAUC Initial strains at corner Gauss points in the basic coordinate system

UNUSED Unused slot to be left blank

Parameters:

ERRINICR Output-integer-no default. Error code that indicates execution failure

= 0 No error

≠ 0 Indicates execution failure

Remarks:

1. The CASECC entries must correspond to the subcase of interest. The output tables containinitial strains for the INITS that corresponds to the subcase of interest. If INITS is used to inputinitial stresses, the initial stresses are converted to initial strains in the basic coordinate systemusing elastic material matrix at the reference temperature. The reference temperature is readfrom ESTNLH table for the individual elements.

MODUSETF

Modifies the DOF set membership table (USET) for axisymmetric Fourier solution in SOL 401.

Format:

MODUSETF BGPDT,USET,SILS,GEOM4/USETF,RMG,RMG2,SILSF/P1/P2 $




Input Data Blocks:


USET DOF set membership table for g-set

SILS Scalar index list

GEOM4 Table of Bulk Data entry images related to constraints, DOF membership, andrigid element connectivity

Output Data Block:

USETF Modified DOF set membership table for g-set

RMG Modified MPC equation matrix for +1 harmonic (symmetric)

RMG2 Modified MPC equation matrix for -1 harmonic (anti-symmetric)

SILSF Modified 2G size SIL table

Parameters:

P1 Input-integer-default=0. Harmonic index

P2 Output-integer-default=-1. Flag to purge RMG and RMG2P2 = -1 to not purgeP2 = 1 to purge

MPPARV

Generate partitioning vector for extended acoustics-specific sparse data recovery.

Format:

MPPARV CASECC,CONTACT,ECTS,EDT,GEOM2S,EQEXINS/ACPARV/NFLUID/S,N,REQID $

Input Data Blocks:

CASECC Case control data block for all subcases

CONTACT Contact data block

ECTS Element connectivity table for current superelement

EDT Element definition table

GEOM2S GEOM2 for current superelement

EQEXINS EQEXIN for current superelement




Output Data Blocks:

ACPARV Acoustic DOF partitioning vector for sparse recovery, g-set

Parameters:

NFLUID Input-integer-default=0. Number of f-set fluid DOF

REQID Input-integer/output-no default. Results request ID

MPPOST

Post-process extended acoustics results.

Format:

MPPOST CASEDR,UFF,OL1,CONTACT,ECTS,EDT,GEOM2S,EQEXINS/OACPRES1,OACVELO1,OACCINT1,OACPWR1/S,N,REQID $

Input Data Blocks:

CASEDR Case control data block for data recovery of a specific subcase

UFF Displacement/pressure matrix for fluid DOF, f-set

OL1 Table of output frequencies

CONTACT Contact data block


EDT Element definition table



Output Data Blocks:

OACPRES1 Output data block of acoustic pressures at microphone points. SORT1 format

OACVELO1 Output data block of acoustic velocities at microphone points. SORT1 format

OACINT1 Output data block of acoustic intensities at microphone points. SORT1 format

OACPWR1 Output data block of acoustic power for AML regions and GROUPs of 2Delements. SORT1 format




Parameters:


MPPRES

Add microphone point pressures to physical displacements/pressures matrix. Specifically forextended acoustics.

Format:

MPPRES CASEDR,UG,UFF,OL1,GEOM2S,EQEXINS/UGNEW/S,N,REQID $

Input Data Blocks:

CASEDR Case control data block for data recovery of a specific subcase

UG Displacement/pressure matrix for all DOF, g-set

UFF Displacement/pressure matrix for fluid DOF, f-set

OL1 Table of output frequencies



Output Data Blocks:

UGNEW New displacement/pressure matrix for all DOF, g-set, that now includesmicrophone point pressures

Parameters:


MPSHAP

Generate mode shape coefficients for extended acoustics-specific microphone points.

Format:

MPSHAP ECTS,PSIFF,PSIG,FREQS/PSIG2/FREQ $

Input Data Blocks:





PSIFF Fluid partition of f-set mode shape matrix or complex frequency response results

PSIG Mode shape matrix or complex frequency response results for the g-set

FREQS List of modal frequencies (only for mode shape inputs)

Output Data Blocks:

PSIG2 Mode shape matrix or complex frequency response results containing coefficientsfor microphone points for the g-set

Parameters:

FREQ Frequency of complex frequency response results (ignored for mode shapes)

RFRCCHK

Performs check for RFROCE and RFORCE1 mixing rules in SOL 401 when LVAR = RAMP.

Format:

RFRCCHK BGPDT,DLTNEW,DLTOLD//S,N,NOGO $

Input Data Blocks:


DLTNEW Dynamic load table for the current subcase

DLTOLD Dynamic load table for the previous subcase

Output Data Blocks:

None

Parameters:

NOGO Output-integer-no default. Flag indicating whether all the rules are satisfied

-1 Test failed

0 Test passed

SAMDB

Creates the material subsystem for MATCZ and MATDMG in SOL 401.




Format:

SDR2 MPT,GEOM2,GEOM3,GEOM4,ECTS,BGPDT,CSTMS,DIT,CASECC,EPT//// $

Input Data Blocks:

MPT Table of Bulk Data entry images related to material properties.

GEOM2 Table of bulk data entry images related to element connectivity and scalar points

GEOM3 Table of Bulk Data entry images related to static and thermal loads

GEOM4 Table of Bulk Data entry images related to constraints, DOF membership, and rigidelement connectivity

ECTS Element connectivity table, output by GP2

BGPDT Basic grid point definition table.

CSTM Table of coordinate system transformation matrices.

DIT Table of TABLEij Bulk Data entry images.

CASECC Table of Case Control command images.

EPT Table of Bulk Data entry images related to element properties.

Output Data Blocks:

None

Parameters:

None

SPCSTRU

SPC all structural DOF for a weakly-coupled fluid/structure analysis. Use to apply SPCD enforcedmotions on the structural side of the fluid/structure matrix AGG to get fluid results.

Format:

SPCSTRU USET,VGFS/USETX $

Input Data Blocks:

USET Table of DOF sets

VGFS G-set partitioning vector for separating fluid DOF from structural DOF




Output Data Block:

USETX Table of DOF sets modified to have all structural DOF restrained by SPCs

Parameters:

None

UMATDBL

Creates a table of user state variables at each Gauss and grid point for elements that use theuser-defined material model (NXUMAT).

Format:

UMATDBL EST,MPT,DITS,BGPDT/UMATINL/ $

Input Data Blocks:

EST Element summary table

MPT Table of Bulk Data entry images related to material properties

DITS Table of TABLEij bulk data entry images


Output Data Blocks:

UMATINL A table of user state variables at each Gauss and grid point for elements that usea user-defined material model



Chapter 14: Problem Report (PR) fixes

Problem Report (PR) fixesThe following list summarizes the problems that are fixed in NX Nastran 11. If applicable, workaroundinformation is provided for use with earlier versions of NX Nastran.

PR# ProblemReported Problem Description

1128879 V9.1

The element corner stresses are incorrect in the case of anunconstrained tapered (that is, non-uniform thickened) CQUAD4element subject to a uniform temperature load. The elementcorner stresses are not zero, although the element centroidstress is zero.

This problem only occurs when you request element force/stressfor tapered CQUAD4 elements under temperature load withCORNER or BILIN option.

The workaround is to use the CUBIC or SGAGE options forstress recovery.

1129324 V9.1 The Edge-to-Surface glue produces inconsistent displacementresults.

1891864 V8.1

For models with constraint RBE elements solved with the sparsesolver, a BIOMSG: ERROR 31 in routine unpack occurs. TheSPCs defined for the last subcase cause the constraint matrixdata block GM to be recreated. However, NX Nastran doesnot recreate the n-set partition of the stiffness matrix (KNN).Consequently, this mismatch of matrix sizes causes the BIOMSGerror to occur downstream.

1959519 V9.0

Because of a missing TEMP(INIT) in a model containingtemperature-dependent material properties, NX Nastrancalculates multiple times higher stress results than expected.

The workaround is to add TEMP(INIT) = 0.0 to the deck, whenTEMP(MATE) / TEMP(BOTH) is present.

1969807 V9.0 The NX Nastran LP64 version outputs unexpected null valuesfor STRAIN ENERGY.

1971779 V9.0NX Nastran SOL101 idles when BOLT, ETYPE=2 is incorrectlydefined. NX Nastran runs in an infinite loop under certain uniquecircumstances.

1972524 V9.0

For models with Edge-to-Surface glue connection, NX Nastranrun terminates with pivot errors. The problem is that gluestiffness is not correctly handled, when the thickness of the shellelements involved in the glue connection is much smaller thanthe length of the edge.



1988483 P10.0

For a specific contact model, where no friction is assigned, NXNastran SOL401 computes the default penalty factors on thehigher side. This causes sticking contact surfaces. Reducingthe penalty factor by an order or two in this instance improvesthe results.

1988734 P10.0 In SOL 401, NX Nastran outputs contact and displacementresults only for the first step.

1988736 P10.0 In SOL 401, the quality of contact pressure results needs to beimproved.

2219470 V8.5

The results of SOL 111 and SOL 111 restart differ, becauserestart is not designed to work with contacts and bolts. Beginningwith NX Nastran 11, any restart with BCSET or BOLTLOADpresent issues a FATAL message.

6313412 V7.1

In SOL 200, NX Nastran terminates an aeroelastic optimizationjob with multiple subcases and boundary conditions.

This occurs in rare circumstances when the software attemptsto add to a Boolean matrix when there is no further need.For example, such a circumstance arises if aeroelastic staticsubcases contain a subcase with only STABDER activeconstrained response types.

This problem does not arise with the DOT, but arises with theSDO optimizer, because DOT does not consider the STABDERresponse as being critical. However, it is critical for the SDOoptimizer due to different types of normalization between thetwo optimizers.

6957768 V8.5

In SOL 101, when the model contains a bolt (CBAR) pre-loadand contact, the iterative solver errors out with

USER FATAL MESSAGE 4295 (MTX267) ELEMENT ID = ... HAS NO

COMPEST DATA BLOCK

This is a damp error, where the iterative solver only usesCOMPEST (composite solid element summary table) for thefirst EMG (computes elemental matrices), but does not use it forthe other EMGs.

The workaround is to not use the sparse solver.

6963259 P9.0

In SOL 101, NX Nastran outputs a memory violation duringcontact refinement for a specific model.

***************************************************

NX Nastran Contact Face Refinement (REFINE)

(version 8.5 )

***************************************************

MAIN: "Access violation" (C0000005) exception encountered.

The workaround for NX Nastran 9 and previous releases is toprovide sufficient memory by using the mem keyword. Beginningwith NX Nastran 11, the newer default memory allocation in the.rcf file enables this model to run.



Problem Report (PR) fixes

7149388 V9.0Restarts are not designed to work with contacts or bolts. Anyrestart with BCSET or BOLTLOAD present are trapped, and NXNastran issues a FATAL message.

7156343 P10.0

In SOL 401, a contact model does not converge with defaultsettings. This model converges in NX Nastran 11 with defaultsettings.

The first step converges faster, if the user defines a largeropen stiffness and reduces the penalty factor by an order ofmagnitude.

7157051 P10.0 In SOL 401, contact is never established in a model with largedisplacement. The model does not converge.

7159395 P10.0

In SOL 401, an unexpected warning about gap size is listed inthe .f06 file.

*** USER WARNING MESSAGE 4690 (CNTGAPERR)

The gap between glue faces of some elements in gap pair

... between regions ... and ... seems overly large.

The largest values are listed in the table below:

ELEMENT ELEMENT GAP

... ... ...

The gap size warning message has been addressed in NXNastran 11. The message will now be printed only when the gapsize is greater than 5% of the average element depth in the pair.

7161096 P10.0 The contact solve performance with SMEM in SOL 401 andperformance in other SOL 401 areas needs to be improved.

7202419 V8.5

The USER FATAL MESSAGE 1126 (GNFIST) occursin a model that contains CBUSH elements withnonlinear/frequency-dependent properties. NX Nastranneeds to be fixed to ignore the PBUSH card that definesthe nonlinear/frequency-dependent properties in a SOL 101analysis.

7254393 V9.0

A FATAL error occurs with an acoustics job, when you changethe CID field of a fluid element grid from -1 to 0 or blank.

NX Nastran 11 now traps:

• Fluid elements attached to structural grids.

• Structural elements attached to fluid grids.

7264830 P10.0

In a SOL 401 2D solid contact and Hertzian type model, the userdoes not expect the contact pressure to vary when the load isconstant.

Beginning with NX Nastran 11, the traction results are constantwith constant load steps.

7269832 V10.0

A SOL 101 model contains several CGAP elements that areconnected to grid points and are SPC'd in all 6 degrees offreedoms. Although this is not the correct way to use suchelements, the code needs to return a gap distance of 0.0 insteadof the KA (Axial Stiffness) as the gap distance.




7271846 V10.0 In SOL 110, when Complex Lanczos with multiple shifts arespecified in EIGC cards, NX Nastran terminates.

7282682 V10.0In SOL 401, the code sends multiple sets of contact separationdistance and contact pressures to a multi-physics executable initerative coupling mode.

7285854 V9.1

In SOL 106, NX Nastran terminates the analysis of anaxisymmetric model that contains CGAP elements. The codedoes not correctly account for the grid coordinates in the followerforce calculation.

Beginning with NX Nastran 11, the code accounts for the gridcoordinates for pressure loads PLOADX1 on XY or XZ plane.

7297350 V9.1

SOL 111 recomputes the modes during restart with MFLUIDand VMOPT, 2.

Beginning with NX Nastran 11, restarts for MFLUID with VMOPTdoes not recalculate the VM modes unless the model is changed.

7307455 V10.0.2The coupling parameter SKINOUT, STOP of the FLSTCNT casecontrol command does not work as expected. It generates anincomplete debug file.

7309929 P10.0 In SOL 108, the code writes incorrect failure index output forplies.

7314132 V9.0The displacement results do not make sense, when the PBENDproperty KY is not equal KZ and FSI = 4,6.

The workaround is to enter KY and KZ reversely, when FSI = 4,6.

7315153 V10.0

NX Nastran outputs unexpected NaN values of strength ratio forHoffman failure theory. They are caused by inconsistent materialfailure constants.

The failure surface of Hoffman failure theory should be convexdue to postulate of maximum plastic dissipation. The failuresurface could be regarded as a kind of yielding surface withoutany hardening. It requires C1*C2 + C2*C3 + C3*C1 > 0(C1,C2,C3 are Hoffman failure constants).

NX Nastran 11 now traps the condition of inconsistent failureconstants and prints the strength ratio value -1.0 instead of theNaN values.

7358482 V9.1The results from an NX Nastran SOL 601,106 analysis areincorrect, when nodes on either side of a glue connection havedifferent nodal output coordinate systems assigned.

7364907 V9.1

In SOL 111, the code does not produce a response at anexcitation location when STATSUB is used. This problem onlyoccurs for the default matrix method of results recovery (thatis, PARAM, DDRMM,0).

The workaround is to put PARAM, DDRMM, -1 in the bulk data.7366452 V10.1 NX Nastran terminates a SOL 601 axisymmetric analysis.




7368953 V10.1

The software reports incorrect eigenvalues for a modal stepdefined with SEQDEP = NO within an NX Nastran SOL 401analysis. It is a modal step that is independent of the previousstep.

7386761 P7.0 In SOL 401 iterative coupling mode, structural results thatcorrespond to certain time increments are missed.

7388548 V10.1

NX Nastran crashes with undefined CS ID, if CS has largenumber ID.

With NX Nastran's LP64 executable the MCID must be less than2,000,000. The NX Nastran fix applies to CQUAD4, CQUAD8,CQUADR, CTRIA3, CTRIA6, and CTRIAR.

The workaround is to use NX Nastran 's ILP64 executable,because it does not have an MCID limit.

7390964 V10.1 BCTPARM, PREVIEW = 1 does not work, when model containsCGAP elements.

7393313 V10.0.1Damping from a non-rotating structure is not correctly includedin a SOL 108 rotordynamics analysis. This problem is fixed inthe new rotordynamics option (PARAM, RLOOPNEW, YES).

7396610 V10.1SOL 401 applies preloads to unused BOLT bulk definitions. Thisresults in incorrect stresses in the preloaded and not preloadedbolt areas.

7399875 V10.1

XYPEAK output requests alter the sorting format for SOL 111results. The XYPEAK card causes NX Nastran to write SORT2OESVM2C rather than SORT1 OESVM1C output.

Beginning with NX Nastran 11, the SORT1 format is writtenalong with the SORT2 formats of the files.

7403868 V10.0 The CMOUT field on the ROTORD card does not work properlyfor a CMOUT value greater than 0.0.

7410679 V9.1

In SOL 601, incorrect table ID's are listed in alerts messagesin the .f06 file.

***ALERT: Timefunction ... does not span the range of

solution times.

7416009 V10.1

Because NX Nastran does not properly account forauto-correlation request without the presence of RANDT1 bulkentries, the solver crashes with the fatal message:

*** SYSTEM FATAL MESSAGE 3011 (RANDOM) ATTEMPT TO WRITE A

TRAILER ON FILE ... WHEN IT HAS BEEN PURGED

7420007 V9.1

The corner cubic stress recovery interior to a superelementis incorrect. The results of CORNER stress/strain output forCQUAD4s with an external superelement are incorrect. Thecorner stress/strain components, as well as principal and vonMises results are not correctly output for CUBIC or BILIN option.

7426468 V10.1 Because of a problem with AUTOSPC, the solver terminates andissues the fatal message 9031.




7430483 V10.0

In rotor dynamics analysis with SOL 111, the code issues theuser fatal message on a model that contains an incorrect FREQset.

*** USER FATAL MESSAGE 3046 (SQFREQ)

THIS FREQUENCY RESPONSE ANALYSIS HAS NO EXCITATION

SPECIFIED FOR IT.

APPLIED LOADS AND ENFORCED MOTION ARE BOTH NULL.

THE RESULT WILL THEREFORE BE A ZERO SOLUTION."

This error message is not correct for this model.

Beginning with NX Nastran 11, the new requirement is thatthe frequency list specified by the FREQUENCY case controlcommand must match the frequencies specified on the ROTORDentry using the RSTART, RSTEP, and NUMSTEP inputs. If theydo not match, a new error will be issued. Loads must still bespecified using the DLOAD case control command.

7435013 V10.1

For SOL 111 models with combination of complex displacementsand velocities via the PARAM, SECOMB, YES statement, NXNastran issues the fatal message:

*** SYSTEM FATAL MESSAGE 7610 (COMBOUT)

OUT1 AND OUT2 ARE INCOMPATIBLE FOR COMBOUT DMAP COMMAND.

The workaround is to only request complex displacements orvelocities (or accelerations) when PARAM, SECOMB, YES ispresent. Another option is not to use PARAM, SECOMB, YES.

7451044 V10.1 A problem with the ACMG module that defines the partitioningvectors for panels causes poor performance of SET3/ELEM.

7458320 V10.1

When multi-core processing is enabled, a SOL 401 analysiscrashes and NX Nastran issues the memory access violationerror:

MAIN: "Access violation" (C0000005) exception encountered.

The workaround is to set SYSTEM(599) = 1. With thisworkaround, only the SMP at the internal force level is turned off,while the remaining piece of functionality that are SMP enabledwill not be affected.

7462050 V10.1

When restarting an NX Nastran SOL 601,106 analysis whereadditional degrees of freedom are added to multi-pointconstraints, the model displaces even though the loading andother boundary conditions remain unaltered.




7476769 V9.0

Because of a problem with a module associated with obtainingresidual vectors related to damping elements (that is,CBUSH1D), the solver crashes and issues the following errorduring a SOL 111 run.

*** SYSTEM FATAL MESSAGE 4276 (QOPEN)

ERROR CODE 3012 PID= 0

The workaround is to set RESVEC = NO in the case controlsection.

7501037 V10.1A specific SOL 601 nonlinear analysis does not run tocompletion, because of problems with the GPFORCE outputrequest and memory consumption.

7508865 V10.0.2 The use of the solution monitor in SOL 200 Design Optimizationis inadvertently activated.

7518378 V10.0

When solving a random analysis using STATSUB and MFLUIDS,NX Nastran issues an incorrect warning message:

*** USER WARNING MESSAGE 982 (SDR3A)

FORMAT OF OUGV1 INCOMPATIBLE WITH SDR3 DESIGN. CODE = 100

...

Codes Cause and User Action

----- ---------------------

100 The ID record is missing on the input file.

The code 100 description is incorrect. Error code 100 means"ID of record not found". The data block being processed bythe SDR3 module is in fact empty. This issue does not affectthe users results.

The workaround is to add PARAM, DDRMM, -1 to the .dat file.This will use a different path to solve the problem, although thispath may be slower than the default path.

7547697 V10.0

Because of a formula that is not consistent with the definitionof CELAS(i) element forces, NX Nastran uses incorrect signconvention for the nonlinear scalar spring (CELAS1) forceresults.

7549657 V10.1

When MID1 in PSHELL is blank and CORNER stress or strain isrequested, NX Nastran issues the fatal message:

*** USER FATAL MESSAGE 3005 (SDR2)

ATTEMPT TO OPERATE ON THE SINGULAR MATRIX (NONE) IN

SUBROUTINE SQD43D

The workaround is to enter a MID1 value, or request stress orstrain with CENTER or CUBIC option.

7557152 V10.1

The data recovery phase performed during an NX NastranSOL 101 analysis on Windows takes significantly longer, if themesh contains linear hexahedral elements than it does for anequivalent mesh that contains parabolic tetrahedral elements.

7558402 V10.0.2When you use SUBCASEs to apply multiple load sets in a singleexternal superelement analysis run, NX Nastran issues an errorand terminates.




7561646 P10.0 When shells do not have mid-side nodes, the acoustic couplingcode fails.

7563147 V10.0.2 In SOL 601, the strain values do not increase on a yield curve,when CVSSVAL = 1 and the strain at yield is large.

7568889 V10.1

NX Nastran SOL 601 crashes, when multiple MCID cards arepresent.

The workaround for models that contain isotropic material is toremove the MCID cards. Isotropic material does not need theMCID cards.

7614946 V10.1Due to non-existent grids the code is inadvertently forced toperform a full solve (that is, sparse data recovery is turned off).This causes the solution to take longer.

7637126 V10.2

Due to the use of the incorrect enforced motion data blockfor the solution time steps by the DMAP code, the relativedisplacements and accelerations of a direct transient solutionare incorrect.

7639078 V10.1NX Nastran calculates incorrect X normal strain results forthermal strain analysis with temperature gradient. This is not astress recovery issue, and it only exists in total strain calculation.

7652311 V10.0 In SOL 112, NX Nastran issues a fatal error message, when ittries to partition K4HH.

7657686 V10.0

When using the element iterative solver with SYSTEM(395)= 1 set, CASI creates a PCS scratch file in the sdir directory.Beginning with NX Nastran 11, the PCS file is moved to the OUTdirectory and renamed as the OUT name.

7658984 V10.2

A fatal error occurs, when you use SYSTEM(370) =5, SYSTEM(589) = 2, and PARAM, COUPMASS, 1for a CQUAD4/CTRIA3 model., and convert them toCQUADR/CTRIAR elements. Also, two PSHELL cards aredefined and used. One PSHELL contains MID1/MID2/MID3,and the other has only MID1.

7672855 V10.2

A NX Nastran Rotor Dynamics job takes a very long time tosolve.

Beginning with NX Nastran 11, a rewrite of the code that createsthe bearing matrices reduces the solve time.

8253296 P10.0

The stability and performance of a SOL 401 creep analysisneeds to be improved.

Beginning with NX Nastran 11, the Euler integration is differentlyused and the maximum creep increment to elastic strain ratio(CRCERAT in NLCNTL) is set to 0.4 (instead of 0.1) to increasethe estimated time step for creep.

8254008 P10.0

In a specific SOL 401 model with bolt pre load, cyclic symmetryMPCs, and several subcases, the RFORCE load in a subcase isnot being applied. This problem only occurs when the model issolved with contact, but it does not appear with glue.

8254901 P10.0When rigid body motion inadvertently exists in a model, SOL401takes a very long time to terminate the job and does not issue apivot ratio error message.




8269419 V10.1

An NX Nastran SOL 401 multi-physics analysis that containsgeneralized plane strain elements terminates with the followingerror:

Mesh Setup

<NXNastran> mesh

nodes: 0, elements: 0, zones: 0

status = failed

xml file name:

element convention: UNDEFINED

...

mp error: mesh setup stage failed

==== Termination

...

==== Multi-physics solution completed (abnormal

termination)

This problem is due to the NX Nastran DLL that communicateswith the Thermal Solution via the multi-physics executableMP.exe. The DLL does not have the right element codesfor generalized plane strain elements. An issue on theThermal/Multiphysics side in processing these elements alsoneeds to be addressed.



Siemens Industry Software

HeadquartersGranite Park One5800 Granite ParkwaySuite 600Plano, TX 75024USA+1 972 987 3000

AmericasGranite Park One5800 Granite ParkwaySuite 600Plano, TX 75024USA+1 314 264 8499

EuropeStephenson HouseSir William Siemens SquareFrimley, CamberleySurrey, GU16 8QD+44 (0) 1276 413200

Asia-PacificSuites 4301-4302, 43/FAIA Kowloon Tower, Landmark East100 How Ming StreetKwun Tong, KowloonHong Kong+852 2230 3308

About Siemens PLM Software

Siemens PLM Software, a business unit of the SiemensIndustry Automation Division, is a leading global providerof product lifecycle management (PLM) software andservices with 7 million licensed seats and 71,000 customersworldwide. Headquartered in Plano, Texas, SiemensPLM Software works collaboratively with companiesto deliver open solutions that help them turn moreideas into successful products. For more informationon Siemens PLM Software products and services, visitwww.siemens.com/plm.

© 2016 Siemens Product Lifecycle ManagementSoftware Inc. Siemens and the Siemens logo areregistered trademarks of Siemens AG. D-Cubed,Femap, Geolus, GO PLM, I-deas, Insight, JT, NX,Parasolid, Solid Edge, Teamcenter, Tecnomatix andVelocity Series are trademarks or registered trademarksof Siemens Product Lifecycle Management SoftwareInc. or its subsidiaries in the United States and in othercountries. All other trademarks, registered trademarksor service marks belong to their respective holders.

nx nastran 11 release guide - smart-fem.de · pdf filenx nastran 11 release guide. contents...

Documents