Occupant Safety of Low-Mass Rigid-Belt Vehicles

Low-mass vehicles (LMV) are characterized by a total mass of 500 - 600 kg and an overall length of 2.5 m - 3.0 m. In order to provide sufficient transportation capacity, they should be relatively wide (1.7 m) and high (1.6 m). Occupant safety associated with such vehicles poses unique problems. According to published accident and injury statistics, a negative correlation exists between vehicle mass and injury severity in car-to-car crashes. In part, this finding can be attributed to the fact that small vehicles today are designed according to conventional design strategies involving however only a small frontal deformation zone and minimal side protection. For a LMV which is even smaller and lighter than present “small” cars another solution has to be found.

A number of frontal and side impacts staged by our group with the aid of a LMV test device along with a mathematical model analysis indicate that a Rigid-Belt Body (RBB) represents a concept which is well suited for LMVs. In all tests performed, occupant protection criteria were met. Provided 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 with higher mass. It is furthermore argued that the RBB characteristics do not adversely influence car-to-car crash compatibility due to the low mass of the vehicle. Likewise, requirements relating to pedestrian and two wheeler safety can be integrated into the RBB concept.