A study of locomotive undercarriage equipment case design using composite materials and finite element analysis

The research, commissioned by Brush Electrical Machines Ltd. of Loughborough, centres around the design of locomotive undercarriage equipment cases. These cases are generally of mild steel construction and are used to carry a wide variety of equipment from electromechanical switchgear to electronic monitoring equipment. Reviewing their design showed that they tend to be overdesigned, complex structures, with their manufacture and assembly being labour intensive and costly. In the competitive traction engineering market, with severe weight penalties featuring in all present day contracts it is important minimise weight and 'costs. Hence, it was proposed to investigate the possibility of redesigning a case in composite material in order to produce a light weight, less complex structure to satisfy the standard railway service loads at a reduced cost. Finite Element Analysis was used extensively in the research, initially to evaluate the structural integrity of a typical steel case indicating the weak points of the design and providing an accurate value for the mass of the case, it was then used in the development of an equivalent composite model. However, as the Finite Element Analysis of composite structures is a relatively new field, it was necessary to perform extensive software testing as a precursor to composite case development in order to assure accuracy of results in terms of stress and displacements. Once confidence in the software had been established an experimental model was developed from uni-directional and woven cloth Glass/Epoxy composites, this was analysed and compared with the earlier analysis of the typical case [continued]…