Suspension parametric analysis of conventional bus through finite element modal simulation

Abstract

Vehicle dynamic response of urban bus for common manoeuvres enhancing purpose has been investigated. Nowadays, increasing concerns on human driver comfort and emerging demands on suspension systems for off-road vehicles call for an effective vehicle ride dynamics model. This study devotes an analytical effort in developing a comprehensive vehicle ride dynamics simulation model. A bus simulation model which consists of two sets of different parabolic leaf springs and shock absorbers, front and rear axle, one dimensional tyres, anti-roll bars and simplified bus body with assumption the chassis is rigid has been built in finite element (FE) environment. Modal analysis is further to be performed in order to calculate the mode shapes and associated frequencies. Subsequently, suspension parameters analysis has been conducted to identify the sensitivity of every component towards the vehicle vibration behaviour. The related suspension parameters in the sensitivity analysis are parabolic leaf spring stiffness, anti-roll bars bending moment, and shock absorber damping characteristics respectively. The mode shapes and natural frequencies change due to the suspension parameters modification could be obviously visualized through finite element method. The visualization capabilities of the mode shape would provide an insight understanding of vehicle vibration behaviour in which is generally complex. The developed vehicle ride dynamics model could serve as an effective and efficient tool for predicting vehicle ride vibrations, to seek designs of primary and secondary suspensions, and to evaluate the roles of various operating conditions.