Nonlinear safety analysis of a running road vehicle under a sudden crosswind

Threats of wind gusts on the safety of road vehicles have been reported around the world, and extensive studies have been carried out to find the accident speeds of road vehicles under a sudden crosswind. However, most previous studies assume that the angular displacements of the vehicle are small and the mass moments of the vehicle remain unchanged during the overturning of the vehicle, yielding a quasi-linear safety analysis of a road-vehicle under a sudden crosswind. This study aims at a nonlinear safety analysis of a running road vehicle under a sudden crosswind by establishing nonlinear equations of motion of a wind-vehicle system. The assumptions adopted in the previous studies are no longer required, and tires can lose or resume contact with the ground. Wind loads on the vehicle are updated with the consideration of the time-varying attitude of the vehicle. The numerical example shows that the proposed nonlinear analysis procedure is more rational than the currently used approaches for progressive instability and the accident vehicle speed of road vehicles.