Search Results

A new approach in numerical occupant simulation using the dynamic coupling of the nonlinear explicit finite element code PAM-CRASH and the crash victim simulation program MADYMO has been validated and is presented. The new technique combines the advantages of the finite element method for the solution of dynamic problems with large structural deformations with the merits of validated occupant models. It uses the full capabilities of both industrial programs PAM-CRASH and MADYMO, and is therefore well suited for an industrial environment. A description of the coupling method will be given in this paper. The study to be presented investigates the interaction of a Hybrid III dummy and a passive restraint system consisting of an airbag and a kneebolster in a frontal impact situation. Both, the airbag and the kneebolster are discretized using finite elements; the dummy model consists of 20 rigid bodies with attached contact ellipsoids.

Numerical calculations with high predictability for the analysis of deformation and nonlinear energy management of car structures during frontal impact are an essential tool when decisisons are needed regarding the structural design of car bodies in white during the early stages of car development without the existence of prototypes. Graphics-aided preprocessing allows the modelling of three-dimensional car structures with about 10,000 finite elements. The numerical calculations are based on the physics of crash metal-forming. The entire analysis is divided into about 40,000 simulated time steps. Supercomputers have to be used so as to enable a single crash simulation to be run overnight, whereas scalar computers would need many days. The results of crash simulation are postprocessed by way of coloured computer graphics which make it possible to assess the deformation of the car structure and to take special engineering results into account.