Vibration Characteristics And Wear Analysis Of Wheel-Rail System In High-Speed Railway Turnout Zone

With the rapid development of high-speed railway,China has higher requirements for the structure of high-speed train and track.As an important part of the track,the special structure of the high-speed turnout makes the wheel-rail contact relationship quite different from that of the ordinary section.The wheel-rail wear problem caused by the vehicle running in the turnout zone is becoming increasingly prominent,which also affects the safety,stability and comfort of the train operation.In order to solve these problems,a method of wheel-rail wear calculation based on multi-body dynamics and finite element method is proposed in this paper.The wear depth and wear number of wheel-rail in turnout zone are estimated,and the wear law under various factor conditions is analyzed,which provides a theoretical reference for maintenance of turnout zone.The main work includes the following aspects:(1)A method for calculating the wheel-rail wear based on multi-body dynamics and finite element method is proposed.At the begining,a vehicle-turmout coupling dynamic model is established based on multi-body dynamics and finite element method.By calculating the normal force,creep force,creep rate of wheel-rail and the size of wheel-rail contact patch,the calculation model of wheel-rail wear is established,and the above results are imported into the wear model as input parameters to obtain the wheel-rail wear in turnout zone.(2)The vehicle-turnout coupling dynamic model is used to analyze the vibration characteristics of wheel and rail with different turnout speed,rail cant,wheel profile and axle load.Under the influence of various factors,the wheel-rail force fluctuates greatly in the switch zone and the crossing zone,and its amplitude is distributed in the crossing zone.Wheel-rail vibration characteristics are well correlated with the influencing factors.(3)Based on the wheel-rail contact model established by the finite element method,the contact patch information of the rail at typical section is calculated when the wheel passes through the turnout directly,and the wheel-rail wear depth is calculated by combining the dynamic analysis results.According to the wear condition of each wheel of the high-speed train,wheel pairs with the worst wear is selected as the analysis object,and the key factors affecting the wear are analyzed.According to the wear situation under the influence of various factors in the turnout zone,some suggestions on the operating conditions of the turnout zone are put forward.(4)Considering the variation of wheel profiles before and after wear,the difference of the wheel-rail contact geometry and the dynamic response of the vehicle are compared and analyzed when crossing in the straight direction under different profiles.With the increase of running distance,the change of the wheel-rail contact geometry increases gradually.Under the condition of wear and no wear,the difference of wheel-rail vertical force is small,and the difference of wheel-rail transverse force is large,mainly in the high frequency components.(5)The wheel-rail vibration characteristics and wear law of turnout zone under the influence of various factors are analyzed.In the process of train's operation,the front wheelset of bogie,as the guide wheelset,bears greater wheel-rail force,and the creep effect of wheel-rail is more intense.The wear problem is also more serious.Wheel flange wear and rail vertical wear mainly occur when trains pass through the turnout zone.