Compatibility considerations for low-mass rigid-belt vehicles

Niederer, Peter F.; Kaeser, Robert; Walz, Felix H.; Brunner, Anton; Faerber, Eberhard

Affiliations

¹Inst. of Biomedical Engineering and Medical Informatics, University of Zurich and Swiss Federal Inst, of Technology, Zurich

²Inst. for Light- Weight Structures, Swiss Federal Inst. of Technology, Zurich

³Institute for Legal Medicine, University of Zurich

⁴Dept. of Accident Research, Winterthur Insurance Co., Winterthur

⁵Bundesanstalt für Strassenwesen (BASt), Bergisch Gladbach, Germany

Abstract

According to published accident and injury statistics a negative correlation exists between vehicle mass and injury severity in car-to-car crashes. Yet, certain vehicles have been demonstrated to deviate jrorn this general rule, in that a favourable safety performance is documented in spite of a relatively low mass. This fact corroborates the hypothesis, that appropriate design strategies facilitate an acceptable safety standard also for low-mass vehicles (IEM?+) in the strict sense (curb mass less than 600 kg).

A number of staged impacts performed by our group with the aid of a LMV test device indicates that a Rigid- Belt Body (RBB) represents such a design strategy. Providing that an advanced restraint system be used and the occupant compartment be appropriately designed, it is expected that an adequate occupant safety performance is reached in a RBB vehicle also for the higher Av environment which is anticipated for LMVs in crashes with conventional vehicles. 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 compatibility. Published data on frontal deformation characteristics indicate however that conventional cars today exhibit an opposite behaviour. To address this problem, two crash experiments were performed together with a theoretical model analysis. A LMV with a mass of 680 kg (incl. batteries, 50% mass of two dummies, instrumentation) designed according to the RBB concept and a conventional car of X320 kg (equivalent loading conditions as LMV were crashed at 56 km/h against a deformable barrier (FMVSS 214). Furthermore, a mathematical model was based on estimated deformation characteristics of conventional vehicles to predict intrusion distances into the FMVSS barrier in hypothetical jrontal 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.

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Year	Entry
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Cited By (4)

Year	Entry
1996	Shearlaw A, Thomas P. Vehicle to vehicle compatibility in real world accidents. In: Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles (ESV). May 13-16, 1996; Melbourne, Australia.607-616.
1995	Kaeser R, Muser M, Spiess O, Frei P, Guenat JM, Wingeier L. Passive safety potential of low mass vehicles. In: Proceedings of the 1995 International IRCOBI Conference on the Biomechanics of Impact. September 13-15, 1995; Brunnen, Switzerland.337-352.
1997	Fachbach B, Steffan H, Staska G. Occupant protection by a moveable seat system. In: Proceedings of the 1997 International IRCOBI Conference on the Biomechanics of Impact. September 24-26, 1997; Hannover, Germany.399-408.
1999	Buzeman-Jewkes DG, Viano DC, Lövsund P. A multi-body integrated vehicle-occupant model for compatibility studies in frontal crashes. J Crash Prev Injury Control. 1999;1(2):143-154.