06_functionsim


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FunctionBay GmbH 2007

FunctionSIM LLC 2008

The RecurDyn Advantage

MAGNA RecurDyn Collaboration

Generating Virtual Powertrain Loads

Single Cylinder Engine Case Study

Summary / Action Items


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FunctionBay GmbH 2007

FunctionSIM LLC 2008

Teams have been challenged to improve their

design processes

Simulation & Analysis are established methods

of troubleshooting design problems

Moving Simulation to the design phase can:Reduce Design &

Testing Time & Costs

Bring it all Together!


4/36 FunctionBay GmbH 2007 FunctionSIM LLC 2008

Established Customer Base

Worldwide Growth & Support

Fast, Robust Simulation Solutions

Cutting-Edge Multi-Physics Technology



FunctionSim LLC

Full Service RecurDyn Distributor

Software Sales and Technical Support

Engineering Services

US Owned and Operated

Close ties to FunctionBay GmbH and FunctionBay Korea


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Media Transport

Worldwide >250 Commercial Customers > 2000 Engineering Seats

75% belong to Fortune Top 500 Companies

Motorsports



Cub Cadet i1000 - Zero Turn Radius MowerZero Turn Radius Mower

MTD ProductsAdvanced Kinematics

Simulation for Design

Featured in Popular Science



Joe Gibbs Racing Engine Dynamics Test & CAE

Looking to Maintain Competetive Edge

Simulating Car of Tomorrow



Solid Elements


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FunctionBay GmbH 2007 FunctionSIM LLC 2008

Enhanced Dynamic Simulation by

Combining FEA and MBS

Finite

Element

Analysis FEA)

Linear, elastic

structures many DOF)

Simulations with

nonlinearities like

bushings or large

movements are not

efficient.

Multi Body

Simulation

MBS)

To rigid bodies

few DOF) limited

Efficient simulations

with nonlinearities like

bushings or large

movements.

Combined

FEA and

MBS

Models with included

large, linear FE

structures

Efficient simulations

with nonlinearities like

bushings or large

movements.

Dynamic Simulation by


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Dynamic Simulation by

FEA MBS FEMFAT

Build FE model of flexible body

define interface points

Build FE model of flexible body

define interface points

FE modal analysis component modes, component mode stressesFE modal analysis component modes, component mode stresses

Import FE - structure into MBS

connect flexible body to rigid bodies

Import FE - structure into MBS

connect flexible body to rigid bodies

Solve hybrid FE-MBS-EHD system

output time series of modal response

Solve hybrid FE-MBS-EHD system

output time series of modal response

N

R

N

AB

Q

A

D

M

S

R

C

N

Import modal loads into FEMFAT

modal stresses, time series modal responseImport modal loads into FEMFAT modal stresses, time series modal response

Multiaxial Fatigue Analysis in FEMFAT

includes contribution of static and vibration loads

Multiaxial Fatigue Analysis in FEMFAT

includes contribution of static and vibration loadsF

M

FA

1

2

3

4

5

6


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Oil Film Model (EHD)

Reynolds differential equation:

+=

+

tH2H

6ZpH

ZBDpH B2

3

2

3

partial elliptic diff. equation

numerically solved (highly optimized)

Navier Stokes Equation

D d

Oil film

yx

H

Squeezing and expulsion of oil film

and dyn. deformations of bearing shell

and pin due to local pressure inside

bearing

H(,z) .... lubrication gap

dy

dx

dz

differential fluid element

inclined position of pin


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Integration of EHD in MBS

Co-Simulation process:

positions & velocities:

force & torqueBearing settings

Diameter

Width

Clearance

Oil viscosity

(Lubricating grooves)

(Oil in-/outlets)

Optional outputs

Journal position and velocity (dislocation orbits)

Pressure distributions at definable intervals

Bearing forces und torques

MBS

EHD


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Modelling Principle

linearized stiffness of

bearing housing

Crankshaft flex. body)

Oil film model:

Connecting

bearing shell and

crankshaftser written

subroutine

Output: force and

torque acting

between bearing

shell and crank

Rigid bearing shell


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Fatigue - based on modal stresses

t)

t

)

... Total deformation of flexible body at time t

i

1

2

... Mode shape FEA result, time invariant) -

Component Modes

q

1 t)

q

2 t)

q

i t)

... Contribution of each mode to the total

deformation at time t. MBS result, skalar

for each mode, time dependent)

t

)

E Tensor

t)

... Total stress state of flexible body at time t

q

1 t)

q

2 t)

i

1

2

... Stress distribution of single mode shape FEA

result time invariant

E Tensor E Tensor

Fatigue Analysis based on


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Fatigue Analysis based on

Modal Stresses

FEA

Modal Stresses

1

2

n

Component Modes

1

2

n

MBS

and

E)HD

Co - Simulation)

Fatigue

n t)

q

2 t)

q

1 t)

Modal

Coordinates

ADAMS Spreadsheet

DAMS Spreadsheet

or Userr UserSubroutineubroutine

Channel 1

Channel 2

FEMFAT

1

q

1 t)

2

2 t)

q

n t)

n

Channel n

Additional

Load Cases

Screwing,...)

e.g.: NASTRAN OP2

.g.: NASTRAN OP2

file

ile


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MFBD Driveline Model

Large Displacements

Local Deformations & Stresses


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Input Drivers

System Outputs

+ Responses

Rigid Driveline Modelat 6degree Inclination

Flexible NASTRAN

model of transmission

Housing (74000 DOF) Torque Input to

Driveshaft

2hrs CPU for 0.6 sec

transient simulation


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Conclusion & Discussion

Dynamic fatigue analysis can be performed in reasonable simulation time

Dynamic fatigue analysis of a

crank shaft is necessary due to

occuring system resonances

Engine run-up to detect all

system resonances within the

engine rpm range;

Damping dominates system

response in a resonance state:

detailed information needed

e.g. damper, flywheel, clutch

....)

Fatigue results within the

whole engine rpm range

Detailed analysis of crank train dynamics / resonances to improve the design


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Engine Performance

Torsional Vibrations and Bearing Loads


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Engine Performance

Bearing Loads versus Time


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Engine Performance

Crankshaft Velocity versus Time

Ch l D fi iti


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Channel Definition

Visualization Channel History


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Visualization Channel History

Visualization S N Curves


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Visualization S-N-Curves

Visualization Haigh Diagramm


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Visualization Haigh-Diagramm

Visualization Equivalent Stress History


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Visualization Equivalent Stress History

Visualization Results


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Visualization Results


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.

Cranktrain Modeling

Global Layout:

Inline, V-eng, boxer, N-cylinderComponent Wizards:

Pistons, Cylinders, Rods, Block

Crankshaft (rigid, torsional, beam)Contact Modeling:

Piston/Cylinder Bore Input

Auxiliary Components:Flywheel, Balancer Shafts,

Equivalent Drive Train,

Torsional Damper


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.

Crank Train Simulation Torsional Vibrations

Bearing Loads

Coupling to Timing Chains

and ValvetrainsFlexible Layouts


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Summary and Discussion

06_functionsim

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