Vehicle Dynamic Simulations Based on Flexible and Rigid Multibody Models

This paper presents the results of a study using multibody models of a vehicle for ride and handling simulations. The aim of this study is to investigate chassis flexibility simulation techniques. For this purpose, three vehicle models are considered: one with a finite element description of the chassis in nodal coordinates; one with a finite element description of the chassis in modal coordinates; and one with a rigid body model of the chassis. In the paper two typical vehicle test operations—sinusoidal depression and pulse steering are considered. Through these simulations, the dynamic effects of the chassis flexibility are monitored for the ride handling analysis. Although the elastic deformation of the chassis is small, the simulation results show a significant difference in the system response when chassis flexibility is considered in the model. In the models where the modal coordinates are used, even a truncated set of modes results into significantly different responses from the rigid chassis model.