Abstract:A new approach was presented to optimize worn wheel reprofiling of the high-speed electric multiple unit(EMU), and three functions were selected as the objective functions, respectively related to the critical velocity of vehicle system dynamics, the contact stress affecting the contact fatigue of wheel-rail wear and the diameter of the nominal rolling circle of a wheel, with vertical coordinates of control points on the wheel profile curve as design variables and their upper and lower values as corresponding additional conditions, with the height, thickness and contact angle of the wheel flange as well as the derivative of the wheel profile curve as geometric constraint parameters. A model of multidisciplinary optimization was established for wheel reprofiling of high-speed EMU, afterwards, corresponding comparison analysis was performed. Results show that, based on the reprofiling model of multi-objective optimization, the comprehensive performance of a standard wheel profile can be closely obtained by not reprofiling the worn wheel to the standard profile, and the amount of wheel reprofiling is reduced and life-time of wheelset is extended.