Roof-to-ground contact force during a vehicle rollover

Abstract

Current US Federal Motor Vehicle Safety Standards require that the roof strength of a vehicle must be such that it is able to withstand a quasi-static force equivalent to times the unloaded of the vehicle, with a maximum roof deformation of 5″ (127 mm). In the public forum, it is often argued that the 1.5 times the unloaded weight rule may not the most effective one for ensuring the safety of vehicle occupants. Therefore, the National Highway Safety Administration has proposed to increase the roof strength requirement to 2.5 times the unloaded of the vehicle for the available roof crush. Currently, no mechanics-based model is available in the literature dealing with the roof-to-ground contact forces when a vehicle is involved in rollover. Therefore, the current study was undertaken to develop two mechanics-based simple models, which can be used for estimating the required roof strength from the calculations of roof-to-ground contact force.