62960 DEVELOPMENT OF WEAR MODEL FOR RAILWAY WHEEL(Railroad System Dynamics)

Abstract

This paper deals with a development of wear model for railway wheel. Wear of the railway wheel is a factor that affects not only the lifetime of wheel but also the performance of railway vehicles such as ride comfort and running safety. Here, practical wear profiles are necessary to reflect the influence of this wheel wear in the vehicle design or the maintenance schedule. However, a lot of time and cost are needed to obtain practical wear profiles through field test. This study aims to a prediction of the wheel wear profile up to the running distance of wheel turning using a multi-body dynamics software SIMPACK. Contact conditions such as contact positions and creep forces between wheel and rail and other components can be obtained from the running simulation. SIMPACK includes a module that can easily treat the wheel-rail contact conditions and calculate the multi-point contact between wheel and rail as well as the one-point contact. Therefore, it is possible to carry out the running simulation using worn profiles of wheel and rail. In this study, the objective is passing through shape curve sections where the wheel wear increases. Thus, the simulation is carried out using the parameter values of vehicle and track considering the subway lines. The value of a wear index is calculated by the method proposed by Krause and Poll. The removed material is proportional to the frictional work dissipated in contact patch and the wear depth is obtained being converted from the removed volume. The worn profile is developed in every running distance of 10,000 km on wheel flange and wheel tread respectively. Also, contact parameters such as rolling radii difference and contact angle difference for the lateral displacements of wheelset are calculated and the lateral forces on both wheels are analyzed in a curved section. As a result, in the comparison with measured wear profiles, it is found that the wear tendency of an actual wheel can be predictable, but the amount of predicted wear differs from that of the actual wheel.