A multilevel approach to the optimisation of a composite light rail vehicle bodyshell

The optimisation of design parameters associated with composite sandwich bodyshell walls of light rail vehicles (LRV) is investigated. The main objective is to evaluate a multi-level computational procedure that leads to optimum wall ply thickness and geometric shapes for areas such as door and window openings. The optimisation procedures are extensively automated whereby iterative finite element solutions are executed under the control of a software suite containing information on the optimisation parameters, objective functions and constraints. The steps in the process include a global finite element analysis of the complete LRV bodyshell subjected to an industry standard loading, identification of a critically loaded panel and its division into domains, and optimisation of a window panel fillet radius within these domains. Numerical results are obtained in order to demonstrate the viability of the method as a design tool.