Dynamic characterization of polymers to improve numerical simulations for passive safety

Abstract The increasing complexity of interior vehicle design means that more powerful finite element models are needed to simulate the crash behaviour of dashboards, door panels and even trim panels. The knowledge of the behaviour of structural components is essential for their design optimisation. Constitutive models describe their material behaviour in finite element codes. The models are in relation with material parameters, which have to be determined. An inverse numerical approach using the results of experimental dynamic tests of polymer samples has therefore been developed to determine these parameters. This inverse method is used to identify the parameters of G'Sell's law taking self-heating and mould flow direction into account. The thermal influence on the mechanical behaviour is studied. The influence of the anisotropy due to the direction of the flow during the filling of the mould is discussed too. The results are compared with the results obtained by classical dynamic uniaxial tensile tests and dart tests. The methodology allows to obtain predictive laws of polymer with dynamic tensile tests for crash simulation improvement.