RADIOSS 27 years - Francis Arnaudeau, Altair

In the seventies crash simulations in automotive, helicopter & plane industries were done at the concept phase with implicit nonlinear code using beam and spring models. At the same time high speed impacts were solved with finite difference codes with explicit time integration. In the eighties it took several years for the automotive engineers to validate and accept explicit codes to solve car crashes. This was made possible thanks to the power of CRAY vector computers. In the nineties crash became a Computer Aided Engineering (CAE) driven design process in the automotive industry. Simulation driven design process allows design engineers to test many alternatives at a fraction of prototype test cost. Today explicit code is standard for crash simulation and this paper describes the past evolution of the method in the RADIOSS code. In the nineties RADIOSS was successfully applied to stamping and manufacturing processes, implicit time integration was introduced to speed-up quasi static analysis and to performed elastic return or gravity setting using the same code. From the beginning an Arbitrary Lagrange Euler (ALE) integration scheme was built in RADIOSS allowing to solve several Fluid Structure Interaction (FSI) problems. RADIOSS is today a general purpose non-linear finite element code with several applications in automotive, aerospace, defense, nuclear, civil engineering and consumer goods industries.

Transcript

1. RADIOSS, 27 years of past evolution and future Francis Arnaudeau October 1, 2015
2. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Seventies • First crash simulations • KRASH, Lockheed Aircraft 1973 • Mass Beam and Non Linear Spring • Example : Gazelle • Nonlinear Finite Element Codes [1] • Beam & Spring • Implicit • Example : Helicopter Panel Box Crash Absorber 1976 • 16 nodes • 22 beam elements • 1 month using CDC7600 • Pre & Post by Hand • High Speed Impacts • Finite Difference Hydrodynamic codes • Explicit • Example : HEMP [2] t0 t1 t2 2 [1] Zienkiewicz O.C. , “The Finite element method in engineering science” Mc Graw Hill, 1971. [2] Wilkins M., “Calculation of elastic plastic flow” LLNL, University of California UCRL-7322, 1981.
3. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Explicit-Implicit : Advantages / Drawbacks Explicit Implicit  Conditional stability  Always stable  Small  Large  Precision  Precision  M-1 (diagonal matrix)  [M+aK]-1 (non diagonal)  Low memory (10 MW)  High memory (6000 MW)  Dynamic problems  Dynamic problems  Static problems  Static problems  Shock problems  Shock problems  « Element-by-Element »  Local treatment  Global resolution  Need convergence at each step  High Robustness  High and Coupled nonlinearities  Low Robustness  Null pivots, Divergence, …  Relatively low cost  « Low » CPU, « Low » Memory  Expensive  High CPU, High Memory  Parallelisation  Parallelisation c t t    t  t  ) ( s  ) (ms  2 t     2 t    3
4. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Eighties • MECALOG 1986 • RADIOSS 2D • ALE (Arbitrary Lagrange Euler) [3] • 2D Axisymetric Examples • Taylor Cylinder • Missile Impact • Explosively Formed Projectile Cycles LAG 5459 ALE 2630 [3] Donea J. et al, “An Arbitary Lagrangian-Eulerian finite element method for transient dynamic fluid-structure interactions” Computer Methods in Applied Mechanics , 1982. 4 Explosive Metal Plate
5. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Eighties • RADIOSS 2D • Explosively Formed Projectile (Self Forging Fragment) [4] P. Rouge Matra, Klaus Weimann Ernst Mach Institut, “Consequences on E.F.P. formation of an intentionally created default” Projectile Radiograph [4] RADIOSS [4] 5
6. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Eighties • RADIOSS CRASH • Box Beam Crash Simulations • Explicit • Q4 Shell (Belytschko-Tsay) • Simple node to surface contact • First Full Car Crash Simulations • Example : PSA BX • 7000 elements (CRAY memory limitation) • 10h CRAY-1 • 1s explicit time step • Too coarse mesh to be predictable • Post-Processing Tools (Time History – Animation) • 1989 First Industrial RADIOSS SMP Parallel Version • IBM 3090 • CRAY 6
7. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Eighties • RADIOSS 3D Missile Impact on Concrete EFP 7
8. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Nineties • Crash Simulations Drive Design • Predictable • 30000-60000 shell elements • Test many design changes • Low cost versus prototypes • Example : FORD offset impact model 50% overlap rigid barrier 56 km/h [5] • IRUC 1995 • 30800 elements • Good results • RADIOSS MPP on MasPar 1992 • Conversion in Fortran 90 • First SPMD Version 1996 • Distributed Memory [5] N.K. Saha, “ Safety Development of New Vehicles Using Nonlinear Finite Element Methods ” Ford Motor Company Dearborn U.S.A., IRUC 1995 8
9. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Nineties • New Elements • Shells : QEPH 1996 [6], BATOZ 1998, DKT 1999 • Thick Shell : 16-nodes, 8-nodes • Tetra 10-nodes • … • Material Laws • Composite • … • Cut Methodology • Failure Laws • Contact • SPH • Multi-material 9 [6] Zeng Q., Combescure A., "A New One-point Quadrature, General Nonlinear Quadrilateral Shell Element with Physical Stabilization" Int. J. Numer. Meth. Engng. 42, 1307-1338, 1998.
10. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Nineties • Crash contact specifications • Contact on both side of shell element • Contact between one node and two elements • High concavity • Full reversibility of contact • Surface impact on itself • RADIOSS interface Type 7 • Search algorithm • Node to element • Gap • No crossing : non linear stiffness • RADIOSS interface Type 11 • Edge to edge 10
11. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Nineties • RADIOSS CRASH • NAVAL (FERRY-1990) • TRAIN (TGV - SNCF - 1991) • AEROSPACE (AEROSPATIALE - 1993) • AUTOMOTIVE 11
12. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Nineties • MANUFACTURING • Metal Forming • Cutting • … 12 Numisheet : Front Fender
13. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Nineties • Hypervelocity Impact • Shaped Charge • EOS • Tillotson • Gruneisen • Puff • Polynomial • Sesame Tables 13
14. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Nineties • 2D MACH-3 Wind Tunnel with a Step 14 DENSITY SCHLIEREN
15. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Nineties • M-Crash pre-processor • Material & Property Data Base • Contact • Intersections • Penetrations • Part Connections • Spot-weld, weld line • Joint, Bolt • Model Checker • Safety and Safety Tools • Dummies (developped in European Projects) • Seat • Airbag • Belt • Pretensioner • … 15
16. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. 2000-2010 • Realistic Mesh • 1 to 2 million elements • 0.2 – 0.5 s time step • 3 to 10h CPU in industrial hardware configuration • Material & Failure Laws • Contact Improvements • Robust Design • Sensitivity Analysis • /PARITH/ON • Implicit • Iterative Preconditioned Conjugate Gradient • Gravity setting • Spring back 16
17. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. 2000-2010 • 2006 ALTAIR acquires MECALOG • Integration of RADIOSS in Hyperworks • Increase customer base (100 -> 900 companies) • Simulation Time Reduction • Advanced Mass Scaling (AMS) • Multi-Domain • Car Crash in 5’ • Material & Failure Laws • HyperCrash • HyperForm • Safety 17
18. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. 2010-2015 • CRASH • Detailed Mesh • 2 to 4 million elements • QEPH shell • New Contact • More robust • Less accurate • With or without gap • Hybrid MPP • X-FEM (cracks) • FVM Airbags • SOL2SPH • … 18
19. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. 19 2010-2015 First airbag models have been made with the assumption of uniform pressure (UP) Uniform Pressure assumption is not accurate enough in: • Out of position configurations (OOP) • Side impacts • Curtain airbags CAB • SAB • Opening of airbag cover (e.g. passenger airbags PAB) Solution: take into account gas flow, in particular for the first milliseconds of the airbag deployment Complex problem because the bag is initially folded
20. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. 2010-2015 FVMBAG IMPACTOR TEST SIDE AIRBAG 20 Gas Temperature Velocity Vector
21. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Speed, #CPU cores, Model size ~ X 10 000 25 Years of Performance* Improvement with RADIOSS Cray YMP NEC SX3 Cray C90 6-CPU Cray T90 4-CPU NEC SX4 2-CPU IBM SP2 16-CPU SGI O2K 195 MHz 12-CPU NEC SX5 2-CPU Fujitsu VP5000 4-CPU DELL P3 800MHz 8-CPU COMPAQ ES40 EV68 833 MHz 32-CPU SGI 03000 400MHz 16-CPU Fujitsu AMD Athlon 1,5GHz 32-CPU NEC SX6 8-CPU HP RX2600 IA64 1,5GHz 32-CPU SGI Altix IA64 1,3GHz 32-CPU HP DL585 Opteron 2,2GHz 32-core Intel Xeon EMT64 3,4GHz 32-core IBM X3455 Opteron 2.8GHz 128-core Xeon X5560@2,80GHz 512-core HP SL230-gen8 E5-2670@2.6GHz 32-node 512-core HP BL460c-gen8 E5-2680v2@2.8GHz 64-node 1280-core CRAY XC40 E5-2698v3@2.3GHz 64-node 2048-core 1 10 100 1000 10000 1990 1995 2000 2005 2010 2015 Vector Supercomputers RISC Supercomputers Off-the-shelves Supercomputers 2.2 Vector 2.3 SMP 3.0 SPMD 4.1 5.1 9.0 10.0 11.0 HMPP 12.0 13.0 14.0 * Relative performance given here is objectively based on real RADIOSS benchmarks made during 25 years using different versions and input decks and may not reflect the actual performance of the machines and CPUs listed here RADIOSS Releases
22. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. RADIOSS TODAY Crash and Safety Drop & Impact Blast & Hydrodynamic Impact Fluid- Structure Interaction Terminal Ballistic Forming & Composites Mapping • 1000 customers • Development team • Validation team • Support team ALTAIR RADIOSS Expert Meeting Sophia Antipolis 2012
23. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. FUTURE • Material Laws • Polymers • Foams • Ply-Xfem • … • Parallel MPP • GPU • Safety • Biorid • WordSid • Isogeometric Element • Second Order ALE • Non diffusive CEL • Meshless • Intelligent Contact • … 23 • Optimization • Optistruct • Hyperstudy • Multiphysics – Co-simulation • Acusolve • MotionSolve • Coupling with BEM • … Use case
24. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. FUTURE 24