Racing car chassis optimization using the finite element method, multi-body dynamic simulation and data acquisition

Abstract

This paper presents an optimization methodology applicable to racing car chassis. The proposed procedure is sequentially structured, and starts with analysis of an existing vehicle, goes through an intermediate prototype and finishes with a final design. It is applied to a real case, the redesign of a steel tubular chassis for the ‘Copa de España de vehículos CM’, as part of a full vehicle development. The dynamic response of the existing chassis is modelled using finite element application techniques for structural design and validated with lab tests. In this way, through various modifications using basic static load cases for primary optimization, a completely new design (intermediate) is defined. Then a prototype is built, instrumented and tested in real field conditions (road and circuit). With acquired data from the dynamic behaviour of the car (suspension, steering, engine and transmission, etc.), using multi-body dynamic simulation software, an optimized load case is put forward in order to refine the first prototype. The ultimate goal is a chassis with much increased torsional and bending stiffness, with minimum weight gain, with regard to its interaction with the suspension and steering systems and to the manufacturing feasibility. It is shown that, with an adequate chassis elements configuration, stiffness can be increased by a 300% with just a 5% weight gain. The proposed methodology can be extended to other design (or re-engineering) procedures with rigid limitations in time and resources.