Handling and Longitudinal Performance of a Heavy Vehicle Using Finite Element Method

摘要

Although vehicles are made of flexible structures and components,they are typically modelled with the idealization of rigid body.In recent years,non-conventional approach based on finite element method has been utilizecl to consider the structural flexibility in the simulation of vehicle's dynamic performance.In this study,finite element model of a typical highway bus is used to demonstrate the effect of vehicle's struc:tural flexibility on handling and longitudinal performances.Due to high computational cost associated with large number of degrees of freedom in the finite element model,transient analyses have been carried out using mode superposition method.Pure cornering and comhined cornering and hraking analyses of the bus model have been presented.Longitudinal tire forces,lateral tire forces and steering angle input on front wheels as external loads are applied on the designed bus to carry out the analyses.To evaluate the longitudinal and lateral forces,a four wheel mathematical model has heen derived and simulated in MATLAB with the same parameters as finite element model.Moreover,in order to demonstrate the effectiveness and applicability of the developed large finite element model,comparison between elastic and rigid chassis performance is presented for handling and longitudinal analyses.The responses at the c.g.due to the finite element and rigid hody are found to be comparahle as expected.For handling responses,there is a considerable difference in the load shift when compared with rigid body model.This in turn leads to some difference in the trajectory of the vehicle,which is further affected by the presence of combined braking input.