Investigation of Instability in Crash Analysis on Various Computing Environments

To reduce computing time in crash simulations, parallel version of commercial crash code is widely used. However, the reliability of parallel computing results on the various computing environment has been issued. In this study, the differences in the maximum acceleration, the average and maximum differences in nodal positions are investigated on the various parallel computing environments. First, the effects of aliasing errors in acceleration and the repeatability issues are reviewed in detail. The tables of differences in acceleration s or nodal positions are constructed. Based on the tables, it can be shown that the amount and the tendency of differences depend on the computing environments. The crash models considered are car crash model and helicopter crash model. The hardware platforms considered are IBM SP2, Regatta and self-made Linux clusters. LS-DYNA was used for crash simulation.