Chair: Mary Kay Bunde, Etnus Corporation
    Time: 10:30-Noon
    Room A102/104/106

    Accuracy and Precision of Distributed Memory Crash Simulation

    Clemens-August Thole, GMD National Research Center for Information Technology
    [Authors: Clemens-August Thole, Juergen Bendisch, Otto Kolp, Mei Liquan, Hartmuth von Trotha, Fraunhofer Institute for Algorithms and Scientific Computing]

    Numerical crash simulation on parallel machines shows indeterministic results for certain car models. For a specific BMW car model, the node positions of the crashed model may show up differences of up to 14 cm between several executions on a parallel machine for the same input deck.

    Detailed investigations have shown that these effects are not a result of the parallel execution or a wrong implementation. The indeterminism of the parallel execution is a direct result of numerical bifurcations. These bifurcations are caused either by the numerical algorithms or are a feature of the car design.

    In the case of the BMW car model, the scatter of the simulation results is a direct consequence of buckling of the motor carrier. A slight redesign of this motor carrier resulted in stable simulation results for parallel machines.

    Systems and Software Technology for Automotive Crash Simulation
    Ed Turkel, Compaq Computers
    Jean-Pierre Bobineau, Radioss Consulting Corporation
    [Authors: Francis Arnaudeau, Eric Lequiniou, MECALOG SARL; Ed Turkel, Compaq Computer Corporation; Martin Walker, Compaq Computer EMEA; Jean-Pierre Bobineau, Radioss Consulting Corporation]

    As a result of increasing consumer and regulatory demands, the automotive industry is investing heavily in simulation technology to improve the crash-worthiness of their vehicles. Recent studies have shown that crash simulation is the single largest consumer of system resources in the engineering computing centers of the major automotive manufacturers worldwide.

    The trends in the use of crash simulation include:

    • Increasing the accuracy of simulation by increasing the amount of detail in vehicle models while increasing the model's resolution, resulting in much larger models

    • Increasing demand for more use of crash simulation to facilitate vehicle design decisions, including the use of statistical techniques to optimize vehicle designs.

    • Increasing pressure to reduce the cost of vehicle development, resulting in greater use of simulation in virtual prototyping, while also raising the visibility of IT costs, putting pressure to lower the cost of computing.

    The result of these trends is the increasing use and size of simulation, while also reducing its cost. MECALOG and COMPAQ are collaborating to develop crash simulation solutions that utilize parallel processing on distributed memory systems to provide highly scalable and accurate simulations, while driving the cost of simulation down. The authors will discuss the parallel processing technology used in MECALOG's RADIOSS-Crash combined with the systems technology in COMPAQ's distributed-memory/clustered Tru64 UNIX and LINUX-based Alpha systems, that enable significant improvements in simulation performance and accuracy while driving the cost of simulation down.