Effect of Velocity and Road Conditions on the Roll Over Behaviour of Sports Utility Vehicles

Sports Utility Vehicles (SUVs) are vulnerable roll over type accidents due to their high centre of gravity and operating conditions. This paper details the effect of velocity and road conditions on the roll over behaviour of a popular SUV on Indian road conditions. Road conditions are collected from three accident prone areas of an Indian metropolitan city. The safety critical vehicle dynamics related parameters of a commercial SUV are measured through experiments. These parameters are incorporated within the mathematical modelling and simulations. A multi-body vehicle dynamics software is used in the detailed simulations of vehicle behaviour. The simulations results are pre-validated by the test results of an instrumented vehicle with optical roll sensor, L350 aqua, and data acquisition system. The sensitivity of critical roll over velocity to the variations in road-tire frictional co-efficient, road side slope and radius of curvature are presented. The findings of the dynamic lateral acceleration threshold indicates that proper side slope and better skid resistance are necessary to improve the roll over stability especially for Indian wet road conditions.