Effect of Location of Centre of Mass of a Semi-independently Suspended Automobile on Natural Frequencies

Abstract

Suspension system of an automobile not only supports the body of the vehicle, engine and passengers but also absorbs shocks arising from the roughness of the road. Most of the present day cars are provided with independent suspension for the front wheels and conventional suspension for the rear wheels. Such a suspension system is referred in this paper as semiindependent suspension system. When the automobile is moving, the roughness of the road keeps giving excitations to the suspension system through tyres. The frequency of excitation is directly proportional to the velocity of the vehicle and inversely proportional to the distance between two undulations of the road. The knowledge of natural frequency is important because the designer would prefer to keep the lowest natural frequency much higher than the frequency of excitation. In this paper, an attempt is made to study the effect of centre of mass of the main body on the natural frequencies of the system