A number of staged impacts with the aid of a low mass vehicle (LMV) test device indicates that a Rigid Belt Body (RBB) represents a design strategy that facilitates an acceptable safety standard also for LMV's in the strict sense (curb mass less than 600 kg). The RBB concept raises the problem of compatibility, however. Ideally, the deformability of car front structures should increase with increasing vehicle weight in order to ascertain campatibility. Published data on frontal deformation characteristics indicate, however, that conventional cars today exhibit the opposite behaviour. In order to address this problem, two crash experiments were performed together with a theoretical model analysis. A LMV with a mass of 680 kg designed according to the RBB concept and a conventional car of 1320 kg (equivalent loading conditions as LMV) were crashed at 56 km/h against a deformable barrier (FMVSS 214). A mathematical model was based on estimated deformation characteristics of conventional vehicles to predict intrusion distances into the FMVSS barrier in hypothetical frontal crashes with 56 km/h. The results indicate that due to its low mass a LMV does not represent an excessive compatibility problem for other car occupants in spite of the stiff RBB characteristics.
Abstract