Wirkketten der Energieabsorption

L. Berger, C. Sahr (RWTH Aachen) The occupant protection and especially the pedestrian protection are getting more and more important since several years. The reason is the insufficient safety of the pedestrian against severe injuries during the impact with vehicles. For the reduction of injuries and their severity, design changes within the frontal structure are necessary to absorb energy and to reduce the forces and acceleration acting on pedestrians. Therefore more and more of such structures for energy absorption are considered that are often set-up in multi-material design consisting of highly porous foams as well as energy absorbers with plastic deformation behaviour such as eggbox structures. Combinations of such parts are interacting under crash load. For the layout of new protection systems, it is necessary to predict deformation behaviour and force level of these „interaction chains“. The main purpose of the present study is, together with IVW in Kaiserslautern, to detect and quantify the interactions among structural components in complicated systems, which take place during lowenergy-impact events. Since these interactions often lead to deviation between experimental and simulation results, the accuracy of forecast of the crash simulations will be increased as a consequence of this investigations. The energy absorbing system, investigated in this study, represents an interaction chain of different constituent components: EPP foam, a polymer eggbox structure, steel and aluminum sheets. This interaction chain and its constituent components are investigated experimentally and further modelled with finite element code LS-Dyna. Own experimental material data is used to validate the material models.