robustness analysis significant reduction of scatter ...· robustness analysis – significant...

Fraunhofer SCAI SIDACT GmbH

Robustness analysis Significant reduction of scatter occurrence

Dominik Borsotto, Robin Strickstrock, Clemens A. Thole

Dominik Borsotto

Fraunhofer SCAI SIDACT GmbH

Agenda Background

Methods

Example

Summary

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"The model has been developed by The National Crash Analysis Center (NCAC) of The George Washington University under a contract with the FHWA and NHTSA of the US DOT http://www.ncac.gwu.edu/vml/models.html

Background

Simulation FE Model Sim.Result

Crash Test Car Result

Verification

Fraunhofer SCAI SIDACT GmbH

"The model has been developed by The National Crash Analysis Center (NCAC) of The George Washington University under a contract with the FHWA and NHTSA of the US DOT http://www.ncac.gwu.edu/vml/models.html

Background

Simulation FE Model Sim.Result

Crash Test Car Result

Manufacturing

tolerances

Verification

Fraunhofer SCAI SIDACT GmbH

"The model has been developed by The National Crash Analysis Center (NCAC) of The George Washington University under a contract with the FHWA and NHTSA of the US DOT http://www.ncac.gwu.edu/vml/models.html

Background

Simulation FE Model Sim.Result

Crash Test Car Result

Manufacturing

tolerances

Verification Emulate m.-

tolerances

Fraunhofer SCAI SIDACT GmbH

Background

Contact / no contact 90 contact buckling

Element failures friction

Fraunhofer SCAI SIDACT GmbH

Background

Approach:

Part based thickness variation representing production tolerances

Generate series of simulations

Analyze all simulations at once

Simulation i

Statistics

+ PCA

Fringeplots

Scattermodes

Standard

Postprocessor

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Managing variability can be important

R. Brown, JLR at LS-Dyna conference 2013: Relating Scatter in Occupant Injury to Airbag Behavior

Methods

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Wind (environment)

Shake (design)

Variability may have a structure

Methods

R. Brown, JLR at LS-Dyna conference 2013: Relating Scatter in Occupant Injury to Airbag Behavior

Fraunhofer SCAI SIDACT GmbH

X = X + *Mode 1 + *Mode 2 +..

Mode 1 => horizontal scatter

Mode 2 => vertical scatter

Scatter mode representation

Wind (environment)

Shake (design)

Methods

R. Brown, JLR at LS-Dyna conference 2013: Relating Scatter in Occupant Injury to Airbag Behavior

Fraunhofer SCAI SIDACT GmbH

Can rank by importance

X = X + *Mode 1 + *Mode 2 +..

Principal Component Analysis

Wind (environment)

Shake (design)

Methods

R. Brown, JLR at LS-Dyna conference 2013: Relating Scatter in Occupant Injury to Airbag Behavior

Fraunhofer SCAI SIDACT GmbH

Example: Chevrolet Silverado

Chevrolet Silverado

"The model has been developed by The National Crash Analysis Center (NCAC) of The George Washington University under a contract with the FHWA and NHTSA of the US DOT http://www.ncac.gwu.edu/vml/models.html

Model Chevrolet

Silverado

Year 2007

Number of Parts 679

Finite-Elements

929,131

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Maximum variation of node position in [mm]

Example: Chevrolet Silverado

Fraunhofer SCAI SIDACT GmbH

Example: Chevrolet Silverado

Firewall mode information? X = X + *Mode 1 + *Mode 2 +

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Example: Chevrolet Silverado

1 dominating mode

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Example: Chevrolet Silverado

2 Cluster

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Example: Chevrolet Silverado

Dominating firewall scatter mode at power-brake

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Example: Chevrolet Silverado

Subtraction of power-brake

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Example: Chevrolet Silverado

Dominating firewall scatter mode at longitudinal rail

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Subtraction of longitudinal rail

Example: Chevrolet Silverado

Fraunhofer SCAI SIDACT GmbH

Firewall scatter after design adaptations

Example: Chevrolet Silverado

Desig

n a

da

pta

tions

Fraunhofer SCAI SIDACT GmbH

Summary

Production tolerances can have a big impact on simulation results

Easy emulation of thickness variation triggers model instabilities

PCA based scatter modes reveal instabilities

More robust design

Fraunhofer SCAI SIDACT GmbH

Thank you for your attention!

Dominik Borsotto