Determination, Validation, and Dynamic Analysis of an Off-Road Chassis

Abstract

The chassis of a car can be interpreted as a large spring connecting the rear and the front suspension. A flexible chassis adds another spring to an already complex system being difficult to control the handling and especially the vehicle lateral load transfer. Factors such as handling as well as vibrations are primordial, since a more rigid structure implies smaller prototype deformation along the path. The torsional stiffness relates to the torsional deflection of the structure when subjected to a pure torque acting on the vehicle’s longitudinal axis. The torsional stiffness is one of the main design criteria of a chassis. The problem of settle the best relationship between cost, weight, and chassis rigidity is of great importance in both the development of popular and high-performance cars. The influence of the chassis torsional stiffness on the dynamic and kinematic suspension behavior is still poorly explored, and there are only a few studies in the literature referred for Baja SAE vehicles. This work has the aim of exposing the boundary conditions necessary to determine the chassis torsional stiffness based on the finite element method. Furthermore, the explanation of the methodology to be used for the determination of this parameter in practice and finally the post-processing in which are used lateral dynamic concepts to assess how the chassis torsional stiffness influences the dynamic and kinematic behavior of the vehicle.