Formation mechanism of the double contact bands on the wheel and rail treads of a metro system

Abstract

The contact band on the wheel and rail is an intuitive representation of the wheel–rail contact relationship that affects the dynamic performance of rail vehicles. In this paper, a vehicle dynamics model and the Archard wear model are established in an integrated way using the actual parameters of a metro train. The mechanism of formation of double contact bands on the wheel and rail in a metro line in China is studied by analysing the geometric combination based on the measured data. The influence of double contact bands on the dynamic performance of the metro vehicle is investigated. To suppress the formation of double contact bands, an optimisation method for asymmetric rail profiles in small radius curves is proposed based on the Kriging Surrogate Model (KSM) and the Particle Swarm Optimisation (PSO) algorithm. Through numerical simulations, it is proved that the optimised rail profiles can improve the curving performance and effectively reduce wheel wear. The methodology proposed in this paper can provide useful information on the mitigation of severe double contact bands on wheel and rail.