Influence Of Track System Parameters And The Wheel Web Shape On 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 some working surfaces of rails.The rail corrugation changes the contact state between the wheel and rail,so the comfort of train passengers,the dynamic performances of the 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 occurs on a small curved track.In this paper,the theory that the 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 concluded as follows:(1)Several vehicle/rail system dynamic models are established to study the condition in which the creep force is saturated 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 whose curved radius is smaller than or equal to 350 m.(2)A finite element model of a 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 the 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.(3)The corresponding finite element models are built and the complex eigenvalue analysis is adopted to research the effect of sleeper distances,rail gauges and rail cant on rail corrugation on a tight curved track.The calculation results show that the sleeper distance has few effect on the generation trend of rail corrugation,and the outer rail cant almost has noeffect 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 rail gauge has few effect on rail corrugation on the traditional wheel-rail system.(4)The author builds a new straight web wheel finite element model to study the influence of wheel web shape on rail corrugation on a tight curved track.The results show that the wheel web shape has some impacts on rail corrugation and the straight web wheel can restrain it to some extent.(5)A new type of wheel-rail systems without corrugation is established by optimizing the straight web wheel finite element model.