Industrial finite element analysis: Evolution and current challenges Keynote presentation at NAFEMS World Congress Crete, Greece June 16-19, 2009 Dr. Chief Numerical Analyst Office of Architecture and Technology Siemens PLM, California, USA 1 NAFEMS-2009, Greece
Topics Evolution of technology Evolution of technology Design embedded analysis Life-cycle simulation Computational environment Future directions 2 NAFEMS-2009, Greece
The mid 1970s Structural integrity Evolution of technology Stick models 5,752 node points 2,108 finite elements (bars, beams, springs) 28,924 degrees of freedom 4 eigenvectors 2,679 CPU seconds 1.1 hours elapsed time 1 million words of memory 36 million words of disk space Mainframe computers 3 NAFEMS-2009, Greece
The mid 1980s Dynamic response Evolution of technology Car frames ~50,000 node points ~60,000 finite elements (shells, solids) ~264,000 degrees of freedom 50 eigenvectors 2,505 CPU seconds 0.9 hours elapsed time 60 Mwords of memory 173 Mwords of disk space Supercomputers 4 NAFEMS-2009, Greece
The mid 1990s Optimization of products Evolution of technology 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/O 1.7 hours elapsed time 128 MWords of memory 65 GBytes of disk used Workstation servers 5 NAFEMS-2009, Greece
The mid 2000 s Simulation of product behavior Evolution of technology 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 used Personal computers 6 NAFEMS-2009, Greece
Topic Evolution of technology Design embedded analysis Design embedded analysis Life-cycle simulation Computational environment Future directions 7 NAFEMS-2009, Greece
Design embedded analysis process Program Approval CAD Freeze Prototype Build Design freeze Production Build Conceptual Design Detail Design Design Testing Design embedded analysis Analysis Geometry changes Optimization Geometry Design changes Simulation Analysis Impacts Design Validation Analysis Fewer physical prototypes -> Cheaper Easier decision making -> Faster More reliable product -> Better 8 NAFEMS-2009, Greece
Finite element assemblies Design embedded analysis Geometric models of components from different sources Meshing of component models executed separately Connection of finite element mesh assemblies needed 9 NAFEMS-2009, Greece
Mesh connection technology Assure displacement and stress continuity across connection Design embedded analysis Apply connection technology in dynamic analyses Dissimilar (different type and size) mesh connections 10 NAFEMS-2009, Greece
Mesh connection technology challenges Non-coincident face connection Non-parallel face connection Design embedded analysis Edge-to-edge connections Edge to surface connections 11 NAFEMS-2009, Greece
Dissimilar mesh connection case study Design embedded analysis 12 NAFEMS-2009, Greece
Topic Evolution of technology Life-cycle simulation Design embedded analysis Life-cycle simulation Computational environment Future directions 13 NAFEMS-2009, Greece
Life-cycle simulations Production phase Material manufacturing Assembly process Life-cycle simulation Operational phase Operational scenarios User comfort optimization Recycling phase Disassembly process Material recycling 14 NAFEMS-2009, Greece
Operational scenarios Life-cycle simulation Rough road vibration Tire patch inputs Driver seat acceleration Wheel unbalance Wheel hub force inputs Steering wheel vibration 15 NAFEMS-2009, Greece
Optimization of user comfort Structural acoustics Life-cycle simulation Automotive vehicle interior noise due to road load excitation, engine noise of wind shear Airplane cabin interior acoustics due engine noise Aero launch systems acoustics Air-conditioning system noise 16 NAFEMS-2009, Greece
Acoustic coupling interface challenges Normal tolerance =.75 Structure Face (Green) Life-cycle simulation Normal tolerance =.25 Y X Fluid Face (Grey) Structure Face (Red) Z Fluid face X Structure faces 17 NAFEMS-2009, Greece
Acoustic analysis case study Life-cycle simulation 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 results Benchmark NORML =.75 NORML =.5 NORML =.25 18 NAFEMS-2009, Greece
Topic Evolution of technology Computational environment Design embedded analysis Life-cycle simulation Computational environment Future directions 19 NAFEMS-2009, Greece
Computational environment challenge Computational environment 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 20 NAFEMS-2009, Greece
Computational problem challenge The constrained stiffness matrix of an analysis problem Computational environment 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 21 NAFEMS-2009, Greece
Finite element model distribution as answer Multilevel graph partitioning: coarsen, partition, refine 9 6 3 9 6 3 9 6 6 3 9 6 9 6 Computational environment 4 1 2 7 8 4 8 4 2 2 8 1 7 5 1 7 7 5 5 7 4 2 4 2 1 7 4 2 3 6 1 2 4 5 22 NAFEMS-2009, Greece
Distributed normal modes analysis case study Computational environment Car engine model ~1,400,000 node points ~790,000 finite elements ~ 4.2 million degrees of freedom 256 components, ~1000 modes 6000 5000 4000 3000 2000 1000 Elapsed time in minutes Total Eigen 64 node Linux cluster 1.85 GHz CPUs 200 GB local disk space per node 4 GB memory per node Gigabit interconnect with MPI 60 50 40 30 20 10 Elapsed speedup Total Eigen 0 0 1 2 4 8 16 32 64 0 0 1 2 4 8 16 32 64 23 NAFEMS-2009, Greece
Distributed transient response calculation case study Computational environment Car body road excitation ~1,096,000 node points ~ 1,000,000 finite elements ~ 6.5 million degrees of freedom ~200 responses 1.20E-08 1.00E-08 8.00E-09 6.00E-09 4.00E-09 Clock min I/O GB 4,728:18 23,839 894:22 7,570 392:47 2,786 Global Lanczos method 256 components, 5. scale 128 components, 2. scale 2.00E-09 0.00E+00 0 20 40 60 80 100 120 140 160 180 200 24 NAFEMS-2009, Greece
Topic Evolution of technology Design embedded analysis Future directions Life-cycle simulation Computational environment Future directions 25 NAFEMS-2009, Greece
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) Future directions 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 26 NAFEMS-2009, Greece
Mesh-free Kantorovich technique Boundary value problem: Distance function: Physical field: Future directions u Ω u( u( x, y ) ( x, y ) Ω = 0 = x, y ) = f ( x, y ) ( x, y ) Ω ;u f ( x, y Ω = 0 ) ω( x, y > 0,( x, y ) Ω ) = 0;( x, y ) Ω Φ ( Ac x, y = F ) m = c j =1 j b j Complete solution: u( x, y ) = ω( x, y ) Φ( x, y ) 27 NAFEMS-2009, Greece
Stochastic analysis technique Deterministic optimization: Probabilistic optimization: 2,60E+09 2,60E+09 2,40E+09 h 2,40E+09 h 2,20E+09 2,20E+09 2,00E+09 1,80E+09 1,60E+09 2,00E+09 1,80E+09 σ 1 1,60E+09 σ 2 Stress Maximum [N/m^2] Stress Maximum [N/m^2] 1,40E+09 1,40E+09 1,20E+09 Deterministic Optimum 1,20E+09 Probabilistic Optimum 1,00E+09 1,00E+09 0,2 0,225 0,25 0,275 0,3 0,325 0,35 0,375 0,4 0,425 0,45 0,475 0,5 0,525 0,55 0,575 0,6 0,625 0,65 0,2 0,225 0,25 0,275 0,3 0,325 0,35 0,375 0,4 0,425 0,45 0,475 0,5 0,525 0,55 0,575 0,6 0,625 0,65 Beam Height [m] Beam Height [m] h opt, deterministic < h opt, probabilistic σ 1 > σ 2, 28 NAFEMS-2009, Greece Future directions
Integrated multi-disciplinary analysis YY- Stress PSD RMS=19.7 MPa Future directions Thermal Fluid flow Motion and Controls Fatigue Structural All analysis capabilities in one system Result correlation Stochastic analysis Heat Flow 29Radiation Response Simulation Electronic Cooling Electro-magnetism NAFEMS-2009, Greece Laminate Composites Space LouisSystems Komzsik
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