Conceptual design and numerical validation of a composite monocoque solar passenger vehicle chassis

The concept of the composite monocoque chassis has been implemented in many vehicle designs; however, there is limited open literature defining the process of simulating a composite monocoque chassis. The purpose of this research is to develop a composite monocoque chassis by analysing its structural integrity through an iterative finite element analysis process with the intention of developing a lightweight solar-powered vehicle. Factors that influence this methodology include; the definition of the vehicle loading conditions, failure criteria, and important design parameters, chief among which is the torsional stiffness. The primary design criterion considered is the torsional stiffness which is determined from the application requirements and data available in the literature. The design methodology then follows an iterative process where various geometry and lay-up changes are considered. Under the same loading conditions, with the aim of increasing the torsional stiffness to achieve the required parameter. The ultimate strength of the material was also considered throughout the simulation process however, in most cases, the model failed to meet the torsional stiffness parameter before the material failure or delamination. Secondly, an analysis of the mounting points was conducted to ensure that the chassis is able to withstand the concentrated loads at the suspension mounts. This analysis is concerned with the principal stresses which gives insight into the most suitable orientation of the lay-up. The methodology presented in this paper stands to be supportive in designing a fully composite monocoque chassis for lightweight race vehicle applications.