sairam prabhakar simulation of laminate composite space ... · simulation of laminate composite...

Unrestricted © Siemens AG 2014

FEMAP SYMPOSIUM 2014

Discover New Insights Femap Symposium 2014

May 14-16, Atlanta, GA, USA

Simulation of laminate composite

space antenna structures

Sairam Prabhakar

2014-05-15


Siemens PLM Software

Agenda

• Background

• Workflows for modeling composite antenna structures

• FEMPLY to pre-process composite structures

• Post-processing laminate composite structural analysis with FEMPLY

• SA Toolkit for rapid random response analysis

2014-05-15



Laminate composites for space structures

• Why Composites:

• Lighter

• $10,000 - $100,000 to put a pound of

payload into orbit

• 20% lighter than Aluminum

• Stiffer

• Directional stiffness which can be tailored

• High modulus Carbon fibers – 350 GPa

• Thermally Stable

• Can design zero Thermal Conductivity

Radarsat1

Source: Wikipedia

2014-05-15



Next Generation Composites: MDA Medium-Sized

Reflector

• Medium (0.9 m dia) reflector developed by MDA

Corp and Composites Atlantic

• One of the early composites reflectors: light, stiff

and exceptional thermal stability

• Technology now used by ESA Sentinel satellite

program, Intelsat, and Boeing

• Significant profitability:

• Original development funded by Canadian

Space Agency grant of $939,000

• Revenue generation of ~ $5 Million annually for

MDA Corp

Source: MDA Corp

2014-05-15



Introduction to MAYA

MAYA Simulation is a developer of leading-edge software

packages for a variety of engineering applications

Thermal, CFD, structural, laminates, NVH, durability

Strategic Partner of Siemens PLM Software

OEM provider of software products and components since 1986

VAR in North America, specializing in CAE

105 employees

75 technical staff, 24 Ph.D’s

Extensive experience in CAE consulting using SPLM tools

2014-05-15



MAYA Simulation Technologies

• Over 2 decades of structural analysis experience:

specifically in composite satellite structures

• Structural customers include MDA, Bristol Aerospace,

Composites Atlantic,….

• Recent successes: RADARSAT and CASSIOPE

• FEMAP and NX for Pre/Post. NX Nastran for solving

Source: CSA

2014-05-15



Key steps in structural analysis of composites

• Defining layup:

• “Global” ply definitions

• “Drop-off” definitions

• As-manufactured fiber orientations:

• Draping simulation

• Orientation-consistent NASTRAN PCOMPs

• Ply-wise results processing

• User-defined failure indices from NASTRAN

computed stress/strain results

2014-05-15



FEMPLY is a Composite Ply-Based Modelling tool fully integrated

into Siemens’ FEMAP Pre/Post-processor offering fast, efficient

and simple definition of complex component layups.

FEMPLY Pro extends the

functionality by adding:

• Ply Draping

• Flat Pattern Export

• Laminate Failure Calculations

• Sandwich Stability

Calculations

• Failure Envelope Charting

What is FEMPLY

2014-05-15



What is Ply-based Modeling

Layup Based Modelling Ply Based Modelling

User Defines Layups

/ Properties

User Applies

Properties to Parts of

the Model

User Defines Ply

Extents

Layups / Properties

Automatically Created

and Properties Applied

to Parts of the Model

2014-05-15



Why Perform Ply-Based Modeling?

Layup Based

Modelling

Ply Based

Modelling

No. of Plies to define. 4* 4

No. of Layups to define. 7 1

No. of Properties to define. 7 -

Total User Inputs. 4*+7+7=18 5

*If Post-processing using global ply IDs is required

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Key Features: Simple Ply Definition

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Key Features: Remapping plies on Remeshing

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Key Features: Ply Draping

Ply Interior holes are handled

Draping results can be used to apply properties with modified fibre

angle.

Export draped patterns to DXF

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Key Features: Advanced Post

Layered Results as well

as Critical Ply and Fibre

Angle Output Vectors are

created.

• Max Stress/Strain

• Tsai-Wu

• Hill

• Hoffman

• Puck

• LaRC02

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Key Features: Post-processing sandwich panels

• Skin Wrinkling

• Shear Crimping

• Honeycomb Dimpling

Critical Direction and

Face Output Vectors are

created.

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Key Features: User Defined Failure Theories

• No Programming Skills

Needed.

• Ply stresses, strains

and moduli available as

variables

• Multiple Conditions

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Key Features: Reporting

• Plot Ply Failure Envelopes

• Export Bill of Material and

Layup data to MS Word

• Export Laminate and

Sandwich Failure calculations

to MS Word

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Structural Analysis Toolkit (SA Toolkit) for NASTRAN

• Efficient and accurate random and sine solutions from NASTRAN normal modes results

• Efficient post-processing of Nastran results

• Ranking, sorting, enveloping, filtering

• Summaries by groups, subcases, etc.

• Margins of safety for different failure types

• Direct manipulation of .op2 file data

• Extremely efficient for large models

• Support NX, MSC Nastran

• Windows & Linux

• Automatic Report Generation

• HTML, MS Excel®, ASCII

2014-05-15



SA Toolkit Suite

Random vibration processor

Sine vibration processor

Modal processor

Energy processor

Mass processor

Stress processor

Grid point force processor

Element force processor

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SA Toolkit Random Processor

SAToolkit Random Processor

• Statistics are required to assess the probability of the response’s

magnitude

Source: Wikipedia

• Random theory assumes

that the input follows a

Gaussian distribution.

• The same assumption

applies to the response

2

2

2

2

1)(

x

exp

20

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Examples of response quantities that do not follow Gaussian distributions

• Von Mises stress

Source: Wikipedia

21

2014-05-15




Examples of response quantities that do not follow Gaussian distributions

• Tsai-Wu composite failure index

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Evaluation of non-Gaussian responses

• To evaluate response quantities that do not follow Gaussian distributions, numerical approximations are required:

• Segalman or Fast approximation method for Von Mises stress

• Also need to validate the approximation using Monte Carlo simulation

2014-05-15



Peak Results

True peak stresses and failure metrics based

on a probability level that is either:

• Directly specified, OR

• Equivalent to a Gaussian pdf with specified

standard deviation • eg 99.73% = 3 sigma

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Efficient and Accurate Interpolation

Uses NX Nastran eigenvectors from a SOL 103 run

• High-performance integration algorithm

• Does not require frequency card (FREQ) definition

• Avoids the risk of error by under-specification of number of computation

frequencies

• Only need to supply the minimum and maximum frequency bounds for the

simulation

2014-05-15



High Performance Solver

Composite tube model benchmark

• 29,000 solid elements

• 60 plies defined on PCOMPS card

• SOL 103 .op2 file size: 1.82 GB

• Stress request: Bottom/middle/top

• Peak ply stress extraction: 58 secs

• Peak max stress failure index extraction: 1 min 12 secs

2014-05-15



Random Ply Results

• Elemental • Ply stresses, strains

• Homogeneous stresses and strains, Von Mises stresses

• Shell resultants, 1D and 3D element forces

• Nodal • Acceleration, displacement, velocity, grid point force, mpc

force, spc force

• Relative or absolute displacements,

velocities and accelerations

• Number of positive crossings

• All entities or selected groups

22 ( )( )1 1

02 2

( )

UU

LL

U

L

S dS d

NRMS

S d

2014-05-15



Compensation for Modal Truncation

Modal Truncation Effects

• Account for modal truncation effects via either:

• Residual vectors via the NX Nastran RESVEC Case Control request, or

• Residual flexibility approach via the supplied DMAP

2014-05-15



Conclusions

• FEMAP is an effective pre/post environment for laminate composite antenna

structure analysis

• FEMPLY provides enhanced workflows for composites structural analysis:

• Global ply based modeling

• Ply draping simulation

• Efficient results processing

• Complete set of polynomial and advanced failure theories

• User-defined failure theories

• SA Toolkit provides a fast and powerful tool for random response analysis

2014-05-15



Contact

Sairam Prabhakar

Senior Technical Specialist

MAYA Simulation

4999 St. Catherine West

Montreal, QC, H3Z 1T3

Phone:

Fax: (514) 369-5706

Mobile: (514) 690-7247

E-mail:

[email protected]

sairam prabhakar simulation of laminate composite space ... · simulation of laminate composite...

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