Dynamic Effect And Identification Of Rail Corrugation Irregularity In High-speed Railway Based On Three-Dimensional Wheel-rail Transient Dynamic Model

Rail corrugation irregularity in high-speed railway is a kind of regular,periodic and wavy track irregularity.The safety and comfort of vehicle is seriously threatened.With the increase of the running speed,the influence of rail corrugation on the dynamic response of wheel-rail system is more significant,and the safety and comfort of vehicle is also influenced more seriously.Therefore,it is of great significance for the safety and smooth operation of highspeed railway and the maintenance and management of the rail corrugation irregularity to study the wheel-rail system dynamic response and influence rules of the rail corrugation irregularity and to carry out the diagnosis and identification of rail corrugation irregularity.In this paper,the three-dimensional wheel-rail transient dynamic model was established by means of the finite element theory and ANSYS/LS-DYNA finite element simulation software.By using this model,the influence of rail corrugation on the dynamic response of wheel-rail system in high-speed railway was analyzed.Then the rail corrugation irregularity was identified by using the dynamic response of wheel-rail system.The main work of this paper is as follows.Firstly,by means of the ANSYS finite element simulation software,the three-dimensional wheel-rail transient dynamic model was established.Based on the characteristics of implicit analysis and explicit analysis,the solution method was proposed in this paper,which is implicit-explicit sequential solution.The modal analysis of wheelset and railway in the model was carried out to understand the vibration characteristics of wheel-rail system.Secondly,using the established model,the dynamic response characteristics of wheel-rail system were analyzed,and the effects of wavelength,wave depth,vehicle running speed and vertical stiffness of fasteners on the dynamic response of wheel-rail system were analyzed.The results show that the rail corrugation will lead to obvious high-frequency wheel/rail vibration.Under the excitation of the rail corrugation irregularity,the wheel-rail vertical dynamic indexes,such as the wheel-rail vertical force and the axle box vertical acceleration,show the characteristics of high frequency vibration,the frequency range of high-frequency vibration is coincident with the wavelength of rail corrugation irregularity.With the increase of wavelength and wave depth,the wheel-rail vertical dynamic indexes increases first and then decreases.The sensitive wavelength range of rail corrugation irregularities is about 0.08m~0.14 m when the running speed is 200km/h to 350km/h.Under the excitation of the specific rail corrugation irregularity,with the increase of vehicle running speed,the wheel-rail vertical dynamic indexes increases first,then decreases and then increases.The vertical stiffness of fasteners has a little influence on the wheel-rail vertical force and the axle box vertical acceleration,and has a great influence on the rail vertical acceleration and the rail vertical acceleration.Finally,based on the theory of the wavelet analysis,the energy entropy of the wavelet packet of the vertical acceleration of the axle box was calculated,and the time-frequency analysis of the wavelet packet of the vertical acceleration of the axle box was explored.On this basis,the methods of diagnosing the existence of rail irregularity and identifying the longitudinal position,wavelength and wave depth of rail irregularity was proposed.By using this method,not only the wavelength but also the longitudinal position of the rail corrugation irregularity can be effectively identified,but the wave depth can only be identified relatively.