Analysis Of Wheel Wear On Wheel/rail Contact Characteristics And Vibration Characteristics Of Track And Bridge

With China's vigorous development of high-speed railway for more than ten years,it has formed the largest and highest operating speed high-speed railway network in the world.The wheel/rail relationship serves as a link between the vehicle system and the track system.With the increase of train speed and large-scale operation,the interaction between wheels and rails has increased,and wheel/rail wear problems are becoming more striking.The wear of the wheel profile will directly lead to the change of the wheel/rail contact geometry,the deterioration of the wheel/rail interaction,the contact state between the wheel and rail,and the vibration characteristics,which will affect the running quality of the high-speed train.Due to the mutual coupling of the train,track,and bridge systems,the wear of the wheel profile will inevitably affect the vibration characteristics of the rail structure to some extent.This paper is based on the dynamic parameters of an intercity EMU made in China and the fixed interface modal synthesis method,the theoretical contact of the flexible wheelset and the dynamic equations of the train-track-bridge large-scale system,the simultaneous multi-body dynamics software UM and the finite element analysis software ANSYS established a corresponding train dynamics model and established a rigid-flexible coupled dynamics simulation model for a train-track-bridge large system.Systematic research on wheel/rail contact vibration characteristics and the vibration characteristics of track and bridge under the circumstance of wheel profile wear.The main work and innovations are as follows:(1)Consider the high-speed train dynamic model with the flexibility of the wheelset: Establish a flexible wheelset submodel by using the fixed interface modal synthesis method,and a multi-body dynamics dynamic model of the train under the flexible wheelset.(2)Research on wheel wear law: Establish Archard wheel wear prediction calculation model,set corresponding line and speed conditions,combine vehicle dynamics model and wheel/rail contact analysis module to simulate the wear change of wheel profile under different operating mileage.(3)Study on wheel/rail contact vibration characteristics of wheel wear: Explore the impact of wheel wear on the vehicle's dynamic performance,including wheel/rail forces,vehicle vibration characteristics and wear power.The characteristics of changes in wheel/rail contact patch area,contact point distribution,and other characteristics.(4)Study on vibration characteristics of wheels and bridges caused by wheel wear: This paper focuses on the analysis of the impact of wear-type bearings on track and bridge vibration characteristics under different mileages.The results show that wheel surface wear has a significant impact on the track and bridge systems,and the transverse direction The impact is greater than the vertical direction.The lateral vibration displacement and acceleration index of track slab,bridge girder and bridge pier structure gradually increase with the increase of wheel profile wear.In addition,the wear of the wheel profile will cause the main frequency of the track and bridge structure to shift,and the amplitude will be abnormal.This will have more influence on the frequency of the mid-to-high stage.It is suggested that during the design of track and bridge structures,the influence of the change in wheel/rail profile should be taken into account in the coupling dynamic analysis of vehicle-rail bridges,and the impact of wheel/rail profile changes on the track and bridge structure should be reduced.(5)Research on wheel wear characteristics of ballast vibration: Switch is one of the weak links of track line.The impact of wheel wear on switch is analyzed through the No.18 turnout in the lateral direction.During the design process of the high-speed turnout,it is necessary to consider the characteristics of the matching of wheel profiles with different staged wheel wear in order to determine whether the relationship between the kinetic parameters of the wheel and turnout is reasonable,so as to optimize the design of critical parts such as the switch rails and the heart rails,and provide the performance for trains passing through the turnouts.