Abstract:With the head vehicle of CRH3 high speed train and CHN60 standard railway as the research object,a vehicletrack coupled dynamic model was built by using dynamic software RecurDyn.The wheelrail contact relationship was defined by the spring damping model,and the roughness of wheels under different operation mileage was measured.Based on the calculation results of wheelrail contact stiffness by relevant literatures,the dynamic properties of highspeed wheelrail rolling contact was studied,and the result of second wheel pair of back bogie of the head vehicle was selected for data analysis.The results show that with the increase of operation mileage of highspeed train,the roughness of wheel surface is decreased and the contact stiffness between wheel and rail is increased.The wheelrail lateral force is decreased first and then increased with the increase of operation mileage,and its frequency is mainly distributed in low frequency segment below 10 Hz.The wheelrail vertical force is increased with the increase of operation mileage,and there are obvious main frequency bands near 5 Hz,10 Hz and 28 Hz.The wheelrail longitudinal force is mainly composed of the longitudinal component of tangential creep force,which is very similar to the wheelrail vertical force in the distribution of time and frequency domain.