Experimental and numerical results on the crash behaviour of bumper beam-longitudinal systems subjected to 40% offset impact at 15 m/s (54 km/h) impact velocity are presented in this paper. A comparison between previously published low speed (10 m/s) tests results on similar systems and the current high speed (15 m/s) results has been performed. Experiments at high speed revealed a lower peak force in the force-deformation characteristics compared with the low speed tests. The number of lobes that developed in the impacted longitudinal of such a system, was found to be dependent on the impact velocity. The amount of energy dissipated by the bumper beam-longitudinal system in both low and high speed tests was almost the same for the same amount of deformation. Numerical simulations were performed with the non-linear finite element code LS-DYNA, using a user-defined material model. When the heat-affected zone (HAZ) length in the longitudinal was modelled as 20 mm, the simulations predicted much deviation in the force-deformation history compared to experimental tests. The influence of HAZ was examined in sensitivity study. It was found that in order to obtain the experimentally observed system behaviour in the numerical simulations, the HAZ in the longitudinal should be modelled with a length equal to the elastic buckling length.
High speed offset impact behaviour of an automotive bumper beam-longitudinal system
2007
8 Seiten, 12 Bilder, 6 Quellen
Aufsatz (Konferenz)
Englisch
British Library Conference Proceedings | 2005
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