Multi-Objective Profile Design Optimization to Minimize Wear Damage and Surface Fatigue of City Train Wheel

Wear and fatigue of wheels have a great effect on the maintenance of railway vehicles and running safety. In the case of an urban railway where no rail lubrication system is installed, it is reported that the risk of wheel damage is high in curved sections. In the present study, we intended to present a method of designing a wheel profile of city trains that can minimize wear and fatigue in curved sections, using the multi-objective optimization method. In multi-objective optimization, we explored a wheel profile design that can reduce wear and fatigue of wheels at the same time, while also satisfying the design performance constraints, such as the safety against derailment and contact force between rails and wheels. A multi-body dynamic analysis was conducted for design performance evaluation, and the best wheel profile design was produced utilizing the analysis result. A wheel profile with minimized wear, a wheel profile with minimized surface fatigue, and a wheel profile with both minimized wear and surface fatigue that can improve the performance of city train wheels were presented respectively using a Pareto-optimal Solution, which is the result of multi-objective optimization. The running safety performances such as derailment and lateral force of the optimized wheel profiles showed improved characteristics when compared to those of the initial wheel profile.