Study Of The Generation Mechanism And Suppression Measures Of Rail Corrugation On A Tight Curved Track

With the rapid development of urban rail transit systems,the living quality of people has been improved greatly,but some relevant problems arise later.Rail corrugation is a periodic wear phenomenon on the surface of a rail head.The rail corrugation changes the contact state between the wheel and rail,so the comfort of train passengers,the dynamic performance of vehicle systems and the track systems are all badly affected.Meanwhile,the railway departments pay high maintenance fees every year for the rail corrugation remedy.Therefore,it is necessary to recognize the mechanism of the rail corrugation and put forward the measures to suppress the rail corrugation.Rail corrugation more likely generates on a small curved track.In this paper,the theory that saturated creep force may induce frictional self-excited vibration of the wheel/rail system,which is able to cause rail corrugation is used for the study of rail corrugation on a sharp curved track.The main works and results are described as follows:(1)Several vehicle/rail system dynamic models are established to study the creep force saturation between the wheel and rail on curved tracks of different radii using the dynamics analysis software Simpack.The results show that the creep force between the leading wheelset and rail is usually saturated,but the creep force between the trailing wheelset and rail is usually unsaturated on a tight curved track.(2)A finite element model of wheel/rail system is set up by the finite element analysis software Abaqus and the complex eigenvalue analysis is used to study the motion stability of the wheel/rail system on a tight curved track.It is found that the frictional self-excited vibration of wheel/rail system may be induced by the saturated creep force between the wheel and rail on a tight curved track.What’s more,the unstable vibration mainly occurs on the inner wheel and the low rail.In addition,the mesh sensitivity of the wheel/rail system finite element model is analyzed.The contrasting results verify that the mesh precision is satisfied.(3)The corresponding finite element models are built and the complex eigenvalue analysis is adopted to research the effect of sleeper distance and rail cant on rail corrugation on a tight curved track.The calculation results show that the sleeper distance has few effecton the generation trend of rail corrugation,and the outer rail cant almost has no effect on the generation trend of rail corrugation.It is beneficial for suppressing rail corrugation to reduce the inner rail cant appropriately.At the same time,a continuous support wheel/rail system model is established and the complex eigenvalue analysis is used to research the motion stability of the wheel/rail system.The results show that the rail corrugation cannot be eliminated by the continuous supporting track structure.Besides,based on the theory that saturated creep force may induce frictional self-excited vibration of the wheel/rail system,the special rail corrugation on the tracks with different sleeper distances in Bilbao of Spain is studied.The simulation results are in agreement with the field measures basically.(4)The effect of contact angle on the motion stability of wheel/rail system with saturated creep force is researched by a single wheel/rail system model.The simulation results show that when the contact angle is small,the inner wheel/low rail system may produce frictional self-excited vibration,but the situation will not occur in the outer wheel/high rail system.(5)A new type of no-corrugation wheel structure is established by optimizing the wheel structure of the traditional wheel/rail system,and the motion stability of the new wheel/rail system under various working environments is analyzed.The results show that employing the new wheel can effectively suppress the rail corrugation on a tight curved track under diverse conditions.