Technische Universität München
New Approaches for
Shape & Topology Optimization
for Crashworthinesskeynote lecture
Prof. Dr. Fabian DuddeckTechnische Universität München
Technische Universität München
Acknowledgements
May-11 Duddeck 2
My PhD students:
S. Hunkeler, M. Rayamajhi, A. Berger
Queen Mary University of London (QMUL)
K. Volz, T. Dietrich, J. Fender
Technische Universität München (TUM)
C. Ortmann TUM in collaboration with HAW Hamburg
My research partners
K.-U. Bletzinger and his team from the TUM
H. Zimmer, M. Prabhuwaingankar, and the team of SFE GmbH
L. Rota, M. Zarroug (PSA Peugeot-Citroen)
A. Schumacher (HAW Hamburg) and E. Schelkle (ASC-S)
H. Müllerschön (DYNAmore GmbH)
F. Dirschmid, G. Fichtinger, O. Meyer, A. Übelacker, M. Zimmermann (BMW)
J. Will (DYNARDO GmbH)
T. Pyttel (ESI GmbH & FH Gießen-Friedberg)
Technische Universität München
Outline
May-11 Duddeck 3
1. New Challenges
2. State-of-the-Art in Shape & Topology Optimization
for Crashworthiness
3. New Approaches for Shape & Topology Optimization
for Crashworthiness
4. Conclusions
Technische Universität München
Outline
May-11 Duddeck 4
1. New Challenges
2. State-of-the-Art in Shape & Topology Optimization
for Crashworthiness
3. New Approaches for Shape & Topology Optimization
for Crashworthiness
4. Conclusions
Technische Universität München
May-11 Duddeck 5
New Challenges: New Structural Concepts!
ETC/ACC Technical Paper 2009/4F. Hacker, R. Harthan, F. Matthes, W. Zimmer
Aixam MegaMega E-City
BMWE-mini
???
Bolloré/PininfarinaBlue Car
BYDE6
DaimlerSmart ed
General MotorsVolt
HeuliezWill
Mitsubishii-Miev
NissanE-Cube
RevaG-Wiz
Electric Cars
SubaruR1e
Tesla MotorsRoadster
Th!nkCity
VolkswagenTwin Drive
Technische Universität München
www.loremo.com
May-11 Duddeck 6
New Challenges: New Structural Concepts!
Technische Universität München
May-11 Duddeck 7
New Challenges: Electromobility
www.llb.mw.tum.dewww.mute-automobile.de
Technische Universität München
May-11 Duddeck 8
New Challenges: Electromobility
www.llb.mw.tum.dewww.mute-automobile.de
Technische Universität München
May-11 Duddeck 10
Lightweight Design (e.g. SuperLightCar EU Project)
M. Stehlin, Volkswagen 2008
2005 2006 2007 2008 2009
Materials & Manufacturing Technologies
Simulation & Testing
Design Concepts
SP2
Technology-Benchmarking
Forming
Joining
Assembly
SP1
SP3
SLC Body Concept
1) Steel intensive
2) Multi material, economic (ULBC)
3) Multi material, advanced (SLBC)
< 2,5 €/kg
< 5 €/kg
< 10 €/kg
Life Cycle Analysis (LCA) ■ Cost assessment ■ Virtual and physical Testing
End of 2008Complete
Multi-MaterialBody structure
Prototype Demonstration
SP4
Technische Universität München
May-11 Duddeck 11
New Approach: Integral Lightweight Design
SFE GmbH & Porsche
+ Optimal Structure(Size, Shape & Topology)
Established: Multi-material, forming, joining assembly, life-cycle, etc.
+ Optimal Package & Design(New Concepts)
SFE GmbH
Technische Universität München
Concept
Material Steel Aluminium Composites
Topology
Shape
Size (thickness)
May-11 Duddeck 12
Shape and Topology Optimization for Crash
Zimmer, Hänschke
Technische Universität München
Topology Opt. for Crash (1): Ground Structure
May-11 Duddeck 13
• Design variables: size of cross-section areas
• Objectives: acceleration, displacement, compliance
Ground structure approach
Domain ismeshed by
beams.
Pedersen (2004)
Technische Universität München
Topology Opt. for Crash (1): Ground Structure
May-11 Duddeck 14
Rigid wall (sliding) Passenger cabin
Car mass750 kg
Engine75 kg
Tire
Pedersen (2004)
• Implicit FEM• Analytic sensitivities• No contact, no inertia• Low generality in geometry
Technische Universität München
Topology Opt. for Crash (2): Equivalent Static Loads
May-11 Duddeck 15
Communal structurePartly comm. structureTopology variationSpecific structure
Mass-beam model for size, shape and topology optimisation
• Nonlinear crash cases represented by equivalent linear static load cases
• Only beam elements and single masses
• For optimisation: size variablesdimensions of the cross-sections (gauge, height, width, orientation)
• Shape variables:Connection points of the beams
Torstenfelt B and Klarbring A (2007): Conceptual optimal design of modular car product families using simultaneous size, shape and
topology optimization. Finite Elem. in Analysis & Design 43, 1050 – 1061.
Technische Universität München
Shape Opt. for Crash (1): Morphing
May-11 Duddeck 16
Morphing can only realise small geometrical modifications
a More flexible shape optimization methods required
Morphing
boxes
Georgios 2009
Technische Universität München
Shape Opt. for Crash (1): Beyond Morphing
May-11 Duddeck 17
SFE CONCEPT model SFE CONCEPT FE model
H. Zimmer, M. Prabhuwaingankar, F. Duddeck (2009): Topology & geometry based structure optimization using implicit parametric models and LSOPT. 7th Europ. LS-DYNA Conf., Salzburg, Austria.
© SFE GmbH
2011
Technische Universität München
Outline
May-11 Duddeck 18
1. New Challenges
2. State-of-the-Art in Shape & Topology Optimization
for Crashworthiness
3. New Approaches for Shape & Topology Optimization
for Crashworthiness
4. Conclusions
Technische Universität München
Topology Opt. for Crash (3): Hybrid Cellular Automata
May-11 Duddeck 19
Crash analysis
no
Convergence test
yes
Initial design
Update material distribution
using HCA ruleΔx = f(U,U*)
x(k+1) = x(k)+Δx
U(x(k))
Final design
x(k+1)
A Tovar & JE Renaud (2008): Altair HyperWorks Symposium
Technische Universität München
Topology Opt. for Crash (3): Hybrid Cellular Automata
May-11 Duddeck 20
Linear-static
Nonlinearstatic
Nonlineardynamic
v0=40 m/s
0 50 100 150 2000
2
4
6
8
10
12
14
16
x 105
linear
nonlinear
dynamic
A Tovar & JE Renaud (2008): Altair HyperWorks Symposium
Technische Universität München
Topology Opt. for Crash (3): Hybrid Cellular Automata
May-11 Duddeck 21
Hunkeler (PhD thesis), Duddeck (QMUL)
Technische Universität München
Topology Opt. for Crash (4): Graph-based Method
May-11 Duddeck 22
A Schumacher & C Ortmann (2011): CARHS Automotive Grand Challenge
• Setup of different designs with „library
parts“, e.g. beams, panels
• Each library part has a representation as
an attributed mathematical (sub-)graph
• Library parts can be connected to make
up structures
• Topological changes are applied as
changes to the design graph
• Graph based topology optimization is
understood as optimization of the design
graph topology
• Shape optimization is applied in an inner
loop in each topological iteration
Technische Universität München
Topology Opt. for Crash (4): Graph-based Method
May-11 Duddeck 23
A Schumacher & C Ortmann (2011): CARHS Automotive Grand Challenge
Technische Universität München
Topology Opt. for Crash (4): Graph-based Method
May-11 Duddeck 24
A Schumacher & C Ortmann (2011): CARHS Automotive Grand Challenge
quadrangular
panel
beam
triangular panel
coordinate vertex and
structural link
Technische Universität München
Duddeck 25
SFE CONCEPT for Shape and Topology Optimization
SFE CONCEPT: Data Flow
Parametric models revolutionize the VPD
SFE CONCEPT Parametric Model
Points and Lines
Cross Sections
Joints & Beams
Welds, Adhesives
FE Meshes
Freeform Surfaces
Loading, Etc.
Beads, Stamps, Ribs
May-11
Technische Universität München
May-11 Duddeck 26
SFE CONCEPT for Shape and Topology Optimization
SFE CONCEPT: Data Flow
Parametric models revolutionize the VPD
Technische Universität München
May-11 Duddeck 27
Parameterization for Optimization (Two Types)
SFE CONCEPT: Data Flow
Parametric models revolutionize the VPD
Maintaining geometrical and topological compatibility is
nearly impossible
Maintaining geometrical and topological compatibility is automatic and very easy
Challenges in optimization
Explicit parameterization(CAD)
Implicit parameterization(SFE CONCEPT)
Technische Universität München
May-11 Duddeck 28
SFE CONCEPT: Data Flow
Parametric models revolutionize the VPDChallenges in optimization
1.1)
1.2)
1.1)
2.)
• Multi-flange assignment• Joining assignment
• Reparametrising the map-targets• Identifying the flanges/joining
?
Withoutsurface map
Withsurface map
Following information is lost: Automatically done:
Parameterization for Optimization (Two Types)
Technische Universität München
May-11 Duddeck 29
Combined Shape and Topology Optimization
SFE CONCEPT: Data Flow
Parametric models revolutionize the VPD
Objective function& constraints
Design variables
Optimizer(e.g. LS/OPT, in house)
SFE CONCEPT
Designvariables
FE mesh &Boundaryconditions
Batchmode
FE SOLVERLS-DYNA, NASTRAN,
PAM-CRASH, PERMASRADIOSS, ABAQUS
DV-file
ASCII output
Optimization loop
DV in ASCIIformat
Modified design
variables
Script for modelupdate & FE
mesh creation
FE mesh &boundary conditions
Problem definition
(only done once)
Design variables inoptimizer
format
ASCII output
Technische Universität München
Algorithmic Aspects
May-11 Duddeck 30
Hybrid and hierarchical methods for multi-level optimization
Technische Universität München
May-11 Duddeck 31
Combined Shape and Topology Optimization
SFE CONCEPT: Data Flow
Design SpacePackage Opt.
Topology Opt.Principle Load Paths
SFE CONCEPTGeometry Model
Shape & Topologychanges
Refinements
Parametric models revolutionize the VPD
Optimization
Technische Universität München
Topology Optimization for Crash (ESLM)
May-11 Duddeck 32
• Equivalent static load method
(ESLM) and standard topology
optimization (linear FEM).
• Equivalent loads are defined for
different time steps based on
energy considerations.
• Result is embedded in an overall
loop “topology – shape – size”
optimization.
• Result corresponds well to
reference designs
• New design alternatives can be
identified K. Volz (PhD Dissertation)TU München & BMW (2011)
Package Design space
Optimisation model
Result (topol. opt.)
Transfer to shape opt.
Technische Universität München
Topology Optimization for Crash (ESLM)
May-11 Duddeck 33
K. Volz (Dissertation)TU München & BMW (2011)
First load phase Second load case Third load case
Technische Universität München
Topology Optimization for Crash (ESLM)
May-11 Duddeck 34
K. Volz (Dissertation)TU München & BMW (2011)
Technische Universität München
Combined Shape & Topology Opt. (SFE CONCEPT)
May-11 Duddeck 35
K. Volz (Dissertation)TU München & BMW (2011)
Technische Universität München
Conclusions
May-11 Duddeck 36
1. New approaches for topology optimizaton (crash):
• Equivalent Static Load Method (ESLM)
• Hybrid Cellular Automata (HCA)
• Graph-based method
2. New approaches for shape optimization (crash)
• Implicit parameterization (SFE CONCEPT)
• Direct parameterization (CAD-based)
• Morphing, etc.
3. Combined package / material / structure (shape &
topology) optimization required.
Technische Universität München
End.
May-11 Duddeck 37
Trains
Shipping
AerospaceWhite goods
Offshore
Front door
Lift gate
Radiatorsupport
Hood
Frontsub-frame
Automotive
SFE GmbH
Technische Universität München
Contact
May-11 Duddeck 38
Prof. Dr. Fabian DUDDECKFG Computational MechanicsTechnische Universität München
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