Study On The Vibration Characteristics Of Ballast Track Structure And The Wheel/rail Coupling System

With the increasing speed and time of high-speed train operation,the dynamic interaction between vehicles and tracks is gradually strengthened,which leads to the problems such as polygonal wear of wheels and corrugation of rails.The periodic wear between the wheels and the track in the operation of ballastless track leads to the violent vibration between the vehicle system and the track system,which leads to the increase of the vertical force of the wheel and rail,causing serious damage to the wheelset,axle box,bogie and other vehicle system components as well as rail,fastening system,sleeper and other track system components,reducing the service life of the components,but also causes a greater impact and rolling noise,reduces the comfort of passengers,and even endangers the train operation safety.The study shows that the coupling vibration of ballastless track and emu has a certain effect on wheel and rail abrasion,and the vibration characteristics of ballastless track of high-speed railway also need to be studied to study whether the vibration characteristics have an effect on wheel and rail abrasion.Taking the ballast track structure of high-speed railway as the research object,Firstly,the finite element software is used to establish the finite element model of each main component – fastening clip,sleeper and wheelset.The modal characteristics of each component are analyzed through modal analysis,and the modal frequencies and modes of the type W2 clip,the type ? sleeper and wheelset of high speed railway within the frequency range of 0~1200Hz are obtained.Secondly,the vertical and lateral finite element models of ballast track structure are established,in which beam element and solid element are used to simulate the vertical and lateral rail respectively,the solid element is used to simulate the sleeper,and the mass element is used to simulate the ballast layer.Harmonic response analysis is carried out to find out the vertical and lateral vibration of the track respectively,and the vertical and lateral vibration characteristics of the track in the frequency range of 0~1200Hz are obtained,and the influence law of the vertical stiffness of the pad plate,the lateral stiffness of the fastening system and the spacing of the fastening on the vertical and lateral vibration characteristics of the track is analyzed.The finite element model of wheel-rail coupling of ballast track is established by simulating the contact between wheels and rails through the spring damping element.The load action of bogie and the load action of whole train are simulated by means of two and four wheelsets.It can be seen that the vertical and lateral modal characteristics of the rail are independent of the wheelset position.In the frequency range of 0~1200Hz,the vertical and lateral modal characteristics of the rail under bogie load and the load of the whole train are shown as the bending vibration of the inner rail of the wheelsets and the bending vibration of the outer of the wheelsets.In this paper,the characteristics of components,track and wheel-rail coupling modes of ballast track are systematically analyzed,which provides technical support for in-depth analysis of periodic wear of wheel and rail,and improves the study of wheel-rail relationship in terms of natural vibration characteristics.