A multi-objective optimisation method of rail combination profile in high-speed turnout switch panel

This paper presents a multi-objective optimisation method considering the switch and stock rail profiles in the switch panel. Based on the non-uniform rational B-spline (NURBS) theory, a parameterised model of the measured turnout profile is constructed to determine the variables. This study selects the vehicle dynamic performance and wheel-rail contact damage as the objective function to establish a multi-objective optimisation mathematical model that is solved using NSGA-II. Overall performances of the measured profile and the optimised profile are compared and evaluated for two aspects, dynamic performance and wheel-rail contact damage. The following are the conclusions: The maximum lateral vibration acceleration of the axle box is reduced from 2.64–2.09 m/s2, which has a 20.83% decrease. Concerning wheel-rail contact damage, the maximum wear index is reduced from 13.46–11.47 N, the reduction is 14.78%. At the same time, the cumulative surface rolling contact fatigue (RCF) is reduced from 8.29×10−5–7.38×10−5. This article can provide a profile repair method for worn turnouts, which can maximise the comprehensive performance of the turnout within a limited amount of grinding, and can reduce the wheel-rail contact damage of the turnout while taking into account driving stability.