Transient dynamics simulations: parallel algorithms for contact detection and smoothed particle hydrodynamics

ABSTRACT

Transient dynamics simulations are commonly used to model phenomena such as car crashes, underwater explosions, and the response of shipping containers to high-speed impacts. Physical objects in such a simulation are typically represented by Lagrangian meshes because the meshes can move and deform with the objects as they undergo stress. Fluids (gasoline, water) or fluid-like materials (earth) in the simulation can be modeled using the techniques of smoothed particle hydrodynamics. Implementing a hybrid mesh/particle model on a massively parallel computer poses several difficult challenges. One challenge is to simultaneously parallelize and load-balance both the mesh and particle portions of the computation. A second challenge is to efficiently detect the contacts that occur within the deforming mesh and between mesh elements and particles as the simulation proceeds. These contacts impart forces to the mesh elements and particles which must be computed at each timestep to accurately capture the physics of interest. In this paper we describe new parallel algorithms for smoothed particle hydrodynamics and contact detection which turn out to have several key features in common. Additionally, we describe how to join the new algorithms with traditional parallel finite element techniques to create an integrated particle/mesh transient dynamics simulation. Our approach to this problem differs from previous work in that we use three different parallel decompositions, a static one for the finite element analysis and dynamic ones for particles and for contact detection. We have implemented our ideas in a parallel version of the transient dynamics code PRONTO-3D and present results for the code running on a large Intel Paragon.

REFERENCES

• 1: S. ATTAWAY, B. HENDRICKSON, S. PLIMPTON, D. GARDNER, C. VAUGHAN, M. HEINSTEIN, AND J. PEERY, Parallel contact detection algorithm for transient solid dynamics simulations using PRONTO3D, in Proc. ASME Intl. Mech. Eng. Congress & Exposition, ASME, November 1996.
• 2: S. W. ATTAWAY, M. W. HEINSTEIN, AND J. W. SWEGLE, Coupling of smooth particle hydrodynamics with the finite element method, Nuclear Eng. Design, 150 (1994), pp. 199-205.
• 3: M. J. Berger , S. H. Bokhari, A partitioning strategy for nonuniform problems on multiprocessors, IEEE Transactions on Computers, v.36 n.5, p.570-580, May 1987 [doi>10.1109/TC.1987.1676942]
• 4: Geoffrey C. Fox , Mark A. Johnson , Gregory A. Lyzenga , Steve W. Otto , John K. Salmon , David W. Walker, Solving problems on concurrent processors. Vol. 1: General techniques and regular problems, Prentice-Hall, Inc., Upper Saddle River, NJ, 1988
• 5: R. A. GINGOLDAND J. J. MONAGHAN, Kernel estimates as a basis for general particle methods in hydrodynamics, J. Comp. Phys., 46 (1982), pp. 429-453.
• 6: M. W. HEINSTEIN, S. W. ATTAWAY, F. J. MELLO, AND J. W. SWEGLE, A general-purpose contact detection algorithm for nonlinear structural analysis codes, Tech. Rep. SAND92-2141, Sandia National Laboratories, Albuquerque, NM, 1993.
• 7: B. HENDRICKSONAND R. LELAND, The Chaco user's guide: Version 2.0, Tech. Rep. SAND94-2692, Sandia National Labs, Albuquerque, NM, June 1995.
• 8: B. HENDRICKSON, S. PLIMPTON, S. ATTAWAY, C. VAUGHAN, AND D. GARDNER, A new parallel algorithm for contact detection in finite element methods, in Proc. High Perf. Comput. '96, Soc. Comp. Simulation, April 1996.
• 9: C. G. HOOVER, A. J. DEGROOT, J. D. MALTBY, AND R. D. PROCASSINI, Paradyn: Dyna3d for massively parallel computers, October 1995. Presentation at Tri-Laboratory Engineering Conference on Computational Modeling.
• 10: T. J. R. HUGHES, The finite element method - linear static and dynamic finite element analysis, Prentice Hall, Englewood Cliffs, NJ, 1987.
• 11: G. R. JOHNSON, E. H. PETERSEN, AND R. A. STRYK, Incorporation of an SPH option in the EPIC code for a wide range of high velocity impact computations, Intl. J. Impact Engineering, 14 (1993), pp. 385-394.
• 12: M. JONESAND P. PLASSMAN, Computational results for parallel unstructured mesh computations, Computing Systems in Engineering, 5 (1994), pp. 297-309.
• 13: Guy Lonsdale , Jan Clinckemaillie , Stefanos Vlachoutsis , J. Dubois, Communication Reqirements in Parallel Crashworthiness Simulation, Proceedings of the nternational Conference and Exhibition on High-Performance Computing and Networking Volume I: Applications, p.55-61, April 18-20, 1994
• 14: Guy Lonsdale , B. Elsner , Jan Clinckemaillie , Stefanos Vlachoutsis , F. de Bruyne , Michael Holzner, Experiences with industrial crashworthiness simulation using the portable, message-passing PAM-CRASH code, Proceedings of the International Conference and Exhibition on High-Performance Computing and Networking, p.856-862, May 03-05, 1995
• 15: L. B. LUCY, A numerical approach to the testing of the fission hypothesis, Astro. J., 82 (1977), pp. 1013-1024.
• 16: J. G. MALONEAND N. L. JOHNSON, A parallel finite element contact/impact algorithm for nonlinear explicit transient analysis: Part II --- parallel implementation, Intl. J. Num. Methods Eng., 37 (1994), pp. 591-603.
• 17: J. J. MONAGHAN, Why particle methods work, SIAM J. Sci. Stat. Comput., 3 (1982), pp. 422-433.
• 18: J. W. SWEGLEAND S. W. ATTAWAY, On the feasibility of using smoothed particle hydrodynamics for underwater explosion calculations, Comp. Mech., 17 (1995), pp. 151-168.
• 19: L. M. TAYLORAND D. P. FLANAGAN, Update of PRONTO-2D and PRONTO-3D transient solid dynamics program, Tech. Rep. SAND90-0102, Sandia National Laboratories, Albuquerque, NM, 1990.
• 20: T. THEUNSAND M. E. RATHSACK, Calculating short range forces on a massively parallel computer: SPH on the connection machine, Comp. Phys. Comm., 76 (1993), pp. 141-158.
• 21: M. S. WARRENAND J. K. SALMON, A portable parallel particle program, Comp. Phys. Comm., 87 (1995), pp. 266-290.

INDEX TERMS

Primary Classification:
  F. Theory of Computation
  F.1 COMPUTATION BY ABSTRACT DEVICES

Additional Classification:
  C. Computer Systems Organization
  C.5 COMPUTER SYSTEM IMPLEMENTATION

  D. Software
  D.4 OPERATING SYSTEMS

  E. Data

General Terms:
Algorithms, Design, Performance, Theory