Effects of road surface roughness and vehicle suspension on vehicle accidents due to a sudden crosswind gust

摘要

High-sided road vehicles are susceptible to a sharp-edged crosswind gust, which may cause vehicle accidents such as overturning, excessive sideslip, or exaggerated rotation. The dynamic behaviour and possible accidents of high-sided vehicles entering a sharp-edged crosswind gust is thus investigated considering road surface roughness and vehicle suspension. The high-sided vehicle is modelled as a combination of several rigid bodies connected by a series of springs and dampers in both vertical and lateral directions. The random roughness of road surface is generated from power spectral density functions for various road conditions. The empirical formulae derived from wind tunnel tests are employed to determine aerodynamic forces and moments acting on the vehicle. After the governing equations of motion are established, extensive computation work is performed. It is demonstrated that the accident vehicle speed of high-sided road vehicle running on the road of average condition is smaller than that running on the road of very good condition and the vehicle suspension system should be taken into consideration.