High-speed Train Dynamic Performance Simulation And Suspension Parameter Optimization Under Tread Wear

China's high-speed railways developed a lot in recent years,and a large number of EMUs(Electric Multiple Units)have been put into operation.With the increasing of running distance,the dynamics problem of EMUs caused by wheel tread wear has become more and more.Tread wear will have a certain impact on the wheel-rail contact of high-speed trains,thus affecting the stability,safety,and ride comfort of high-speed train operation.The suspension parameters of the bogie have a great impact on the dynamic performance of the vehicle.Optimizing the suspension parameters is an effective way to improve the dynamic performance of the vehicle under the wear condition of the wheel tread.This paper makes a study on the vehicle dynamics of different tread wear conditions,and optimizing the vehicle suspension parameters of different tread wear conditions.The main work of this paper are as follows:Firstly,the dynamic model of a kind of high-speed train is established by using the multi-body dynamics ADAMS/Rail and the model is verified subsequently.Secondly,based on the measured data,the trend of the measured tread shape is analyzed,analyzing the variation of tread wear and study the impact of tread wear on wheel-rail contact,including wheel-rail contact geometry,wheel-rail contact area,wheel-rail contact stress,etc.The effects of tread wear on equivalent conicity of wheel-rail contact and critical speed of the vehicle.Thirdly,studing the influence of vehicle running speed and line condition on the dynamic performance of the model under different wear levels,analyze the trend of dynamic performance parameters with tread wear.The research results show that: the tread wear has a great influence on the nonlinear critical speed,derailment coefficient,wheel-rail lateral force and Sperling lateral stability,and has little effect on the wheel weight-reduction rate and Sperling vertical stability.Finally,the ADAMS-Matlab co-simulation model is used to optimize the suspension parameters of high-speed motor under different wear conditions,building the ADAMS-Matlab co-simulation model,the sensitivity of the suspension parameters of the vehicle is analyzed,the three dynamic performance indexes of high-speed motor trains are used as optimization targets,and the genetic parameters are used as tools to optimize the suspension parameters.The study found: the suspension parameter optimization can improve the dynamic performance under wheel tread wear.In this paper,the influence of tread wear on wheel-rail contact and vehicle dynamics performance is obtained.The research results have certain guiding significance for the optimization of tread shape and tread surface maintenance of high-speed trains.At the same time,this paper optimizes the suspension parameters of vehicles under tread wear.A new method is provided to reduce the adverse effects of tread wear.