Development of a model for predicting wear profiles of rails using multi-body dynamics software

摘要

Rail wear development due to rolling contact between wheels and rails in actual railway systems has been extensively investigated.In particular, corrugation (i.e., wavy rail surfaces produced by wear) is a pattern formation phenomenon that occurs in mechanical dynamic systems.Railheads are subjected to severe contact with wheels during repeated passage of trains.Changes to rail profiles due to wear is one of the main factors that adversely affects the stability, safety, and curving performance of railway vehicles. The boundary condition between the rail and the wheel depends on factors such as the operating conditions of the vehicles, the rail curvature, and the track flexibility.It is thus important to predict the development of rail wear.However, observing wear development in practical systems is impractical since it is extremely time consuming.Multi-body dynamics software is a useful tool for analyzing vehicle dynamics since it considers both the car body motion and the wheel/rail contact conditions.Numerical simulation software has been widely used for analyzing the running stability and body vibrations.Rail wear development has also been investigated.However, previous studies have not considered changes to the rail wear profile in the longitudinal direction. The present study proposes a numerical procedure for predicting the rail wear profile by incorporating an original wear calculation program in SIMPACK. The proposed procedure has the following calculation flow.First, the contact pressure and the slip ratio are obtained from motion analysis of the vehicle using SIMPACK and the wear amount is calculated by substituting the contact pressure and the slip ratio into the original user routine. The amount of wear calculated in this step is applied to the rail profile, which isset as the new track in SIMPACK.In this procedure, the rail profile is remodeled by spline interpolation to the adjacent rail profile. The present paper presents the numerical results obtained. The amount of wear for the contact conditions is considered and the validity of this approach is discussed. The wear development mechanism is also discussed from the viewpoint of mechanical and tribological contact problems.