Optimization of a wheel profile accounting for design robustness

The article describes a numerical procedure for optimum design of a railway wheel profile. The optimization performed using the optimality criteria based on a rolling radius difference function, which account for the reduction of wear and contact stresses as well as for stability of the vehicle. As a general optimization technique the multipoint approximations method is employed. The described procedure has been applied to improve the wheel profile design for a passenger train that was suffering from rolling contact fatigue defects in the rails and wheels. In order to account for uncertainties inherent to the wheel production process, the robustness of the optimum wheel profile was analysed. The failure criterion was formulated using the vehicle stability requirement. The failure probability was estimated using the Monte Carlo method and modified Latin hypercube sampling technique. The results are presented and discussed.