Topics Evolution of technology...Full car body models ~ 270,000 node points ~ 275,000 elements...

1 Louis Komzsik NAFEMS-2009, Greece

Industrial finite element analysis: Evolution and current challenges

Dr. Louis KomzsikChief Numerical AnalystOffice of Architecture and TechnologySiemens PLM, California, USA

Keynote presentation atNAFEMS World CongressCrete, GreeceJune 16-19, 2009


Topics

Evolution of technology

Design embedded analysis

Life-cycle simulation

Computational environment

Future directions

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The mid 1970s

Structural integrity

Stick models5,752 node points2,108 finite elements

(bars, beams, springs)28,924 degrees of freedom4 eigenvectors

2,679 CPU seconds1.1 hours elapsed time1 million words of memory36 million words of disk spaceMainframe computers

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The mid 1980s

Dynamic response

Car frames~50,000 node points~60,000 finite elements

(shells, solids)~264,000 degrees of freedom50 eigenvectors

2,505 CPU seconds0.9 hours elapsed time60 Mwords of memory173 Mwords of disk spaceSupercomputers

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The mid 1990s

Optimization of products

Full car body models~ 270,000 node points~ 275,000 elements

(spot-welds, constraints)~1.6 million degrees of freedom~1,000 eigenvectors

4,936 CPU seconds 221 GBytes of I/O1.7 hours elapsed time128 MWords of memory65 GBytes of disk usedWorkstation servers

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Simulation of product behavior

Trimmed body models~7 million node points~7.2 million elements(connection elements)

~35 million degrees of freedom~10,000 eigenvectors

~100,000 CPU seconds~11.5 Tera-bytes of I/O~680 minutes of elapsed time~16 GB memory used~630 Giga-bytes of disk usedPersonal computers

The mid 2000’s

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Future directions

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Design embedded analysis process

Fewer physical prototypes -> CheaperEasier decision making -> FasterMore reliable product -> Better

CAD Freeze

Prototype Build

Program Approval

Designfreeze

Conceptual Design Design TestingDetail Design

Analysis Impacts Design

Geometry changesGeometry changes Design changes

Analysis AnalysisValidationSimulation

Production Build

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Optimization


Finite element assemblies

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Geometric models of components from different sources

Meshing of component models executed separately

Connection of finite element mesh assemblies needed


Mesh connection technology

Assure displacement and stress continuity across connection

Apply connection technology in dynamic analyses

Dissimilar (different type and size) mesh connections

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Mesh connection technology challenges

Non-coincident face connection

Non-parallel face connection

Edge-to-edge connections

Edge to surface connections

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Dissimilar mesh connection case study


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Future directions

Lif

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Production phaseMaterial manufacturingAssembly process

Operational phaseOperational scenariosUser comfort optimization

Recycling phase Disassembly processMaterial recycling

Life-cycle simulations

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Operational scenarios

Rough road vibrationTire patch inputsDriver seat acceleration

Wheel unbalanceWheel hub force inputsSteering wheel vibrationL

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Optimization of user comfort

Structural acoustics

Automotive vehicle interior noisedue to road load excitation,engine noise of wind shear

Airplane cabin interior acoustics due engine noise

Aero launch systems acoustics

Air-conditioning system noise

Lif

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Acoustic coupling interface challenges

Normal tolerance = .75

Normal tolerance = .25

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X

Y

Structure Face (Red)

Fluid Face (Grey)

Structure

Face

(Green)

Fluid face

X

Z

Structure faces


Acoustic analysis case study

Benchmark

NORML = .75

NORML = .5

NORML = .25

Full vehicle model ~ 1,400,000 fluid free faces~ 2,000,000 structural faces~ 2,500,000 structural grids

Compute response to 300 Hz

Coupled results agree well with measured benchmark resultsL

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Future directions

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Distributed processor clusters

4 Workstation Servers

4 Processors per server

1.5 GHz processors

16 GB Memory

1 Giga-bit Ethernet Adapter

2 Ultra3 SCSI disks (internal)

2 Ultra3 SCSI controllers for external disks

16x Ultra3 SCSI disks 36.4 GB per controller

Total external capacity: 2x580 GB = 1.1 TB

Computational environment challenge

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Computational problem challenge

The constrained stiffness matrix of an

analysis problem

Number of rows: 35,734,709

Nonzero terms: 1,384,305,995

Nonzero terms in sparse factor matrix:

43,827,004,000

Memory used during factorization:

1,080,732,000 (4 byte) words

Actual elapsed time of sparse

factorization on a high performance

workstation: 335 minutes

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Finite element model distribution as answer

Multilevel graph partitioning: coarsen, partition, refine

4

9 36

57

24

1

2 8

36

57

69

4 2

71

69

4

4 2

7

2

1

9 6

24

9 3

51

6

7

1 2 4

3

5

6

7

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Distributed normal modes analysis case study

Car engine model~1,400,000 node points~790,000 finite elements~ 4.2 million degrees of freedom256 components, ~1000 modes

Elapsed time in minutes

64 node Linux cluster1.85 GHz CPUs200 GB local disk space per node4 GB memory per nodeGigabit interconnect with MPI

Elapsed speedup

0

1000

2000

3000

4000

5000

6000

0 1 2 4 8 16 32 64

Total

Eigen

0

10

20

30

40

50

60

0 1 2 4 8 16 32 64

Total

Eigen

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Distributed transient response calculation case study

Car body road excitation~1,096,000 node points~ 1,000,000 finite elements~ 6.5 million degrees of freedom~200 responses

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0.00E+00

2.00E-09

4.00E-09

6.00E-09

8.00E-09

1.00E-08

1.20E-08

0 20 40 60 80 100 120 140 160 180 200

Global Lanczos method

256 components, 5. scale

128 components, 2. scale

Clock min I/O GB

4,728:18 23,839

894:22 7,570

392:47 2,786


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Future directions

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Future directions

Computational technology will use mixed precision and hybrid solutions on multi and many-core CPU clusters and will utilize graphical processing units (GPUs)

Design embedded analysis will continue to increase the geometric model complexity and will result in the advancement of geometry based mesh-free analysis approaches

The increased fidelity of life-cycle simulations will require stochastic analysis techniques considering manufacturing tolerances and load variations leading to robust designs

The future is integrated multi-disciplinary analysis in the industry

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MeshMesh--free free KantorovichKantorovich techniquetechnique

)y,x()y,x()y,x(u Φω=

FAc

bc)y,x(m

jjj

=

= ∑=1

Φ

∂∈=

∈>

Ω

Ωω

)y,x(;

)y,x(,)y,x(

0

0

0=

∈

=−

∂Ω

Ω

∆

|u

)y,x(

)y,x(f)y,x(u

0=∈

=−

∂ΩΩ

∆

|u;)y,x(

)y,x(f)y,x(u

Complete solution:

Boundary value problem: Physical field:Distance function:

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Stochastic analysis technique

1,00E+09

1,20E+09

1,40E+09

1,60E+09

1,80E+09

2,00E+09

2,20E+09

2,40E+09

2,60E+09

0,2

0,22

50,

250,

275

0,3

0,32

50,

350,

375

0,4

0,42

50,

450,

475

0,5

0,52

50,

550,

575

0,6

0,62

50,

65

Beam Height [m]

Str

ess M

axim

um

[N

/m^

2]

1,00E+09

1,20E+09

1,40E+09

1,60E+09

1,80E+09

2,00E+09

2,20E+09

2,40E+09

2,60E+09

0,2

0,22

50,

250,

275

0,3

0,32

50,

350,

375

0,4

0,42

50,

450,

475

0,5

0,52

50,

550,

575

0,6

0,62

50,

65

Beam Height [m]

Str

ess M

axim

um

[N

/m^

2]

∆σ∆σ∆σ∆σ1∆σ∆σ∆σ∆σ2

∆∆∆∆h ∆∆∆∆h

„DeterministicOptimum“

„ProbabilisticOptimum“

Deterministic optimization: Probabilistic optimization:

hopt, deterministic < hopt, probabilistic ∆σ1> ∆σ2,

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Result correlation

Electronic CoolingRadiation Space Systems

Response Simulation

YY- Stress PSD

RMS=19.7 MPa

Motion and Controls

Integrated multi-disciplinary analysis

Heat Flow Stochastic analysis

Fluid flow

Electro-magnetism

Structural Fatigue

Laminate Composites

Thermal

All analysis capabilities in one

system

Fu

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Thank you for your attention!

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Topics Evolution of technology...Full car body models ~ 270,000 node points ~ 275,000 elements...

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Transcript of Topics Evolution of technology...Full car body models ~ 270,000 node points ~ 275,000 elements...