Simulation Research On The Fretting Wear Of Press-fitted Hollow Axle

With the requirement of high speed and light weight of vehicle increasing,hollow axle is widely used in high speed train.However,the relevant standards have not been formulated for hollow axle in China.In fact,the assembly standard of hollow axle is the same as that of the solid axle.During the maintenance of the high speed train,it was found that the wear of the press position of hollow axle was more serious than that of the solid axle,and thus the hollow axle was scrapped earlier than the solid axle occasionally.In this paper,the fretting wear simulation of small scale press-fitted axle was conducted by a FE wear model which has been verified in a previous study.The simulation result shows that the press-fitted hollow axle exhibits a more serious fretting wear than press-fitted solid axle,and the fretting wear of press-fitted hollow axle can be reduced by increasing interference grips.In order to study the effect of interference grips on the fretting wear of wheel-hollow axle of high-speed train,the fretting wear of wheel-hollow axle was simulated by the FE wear model stated above.The fretting wear of wheel-hollow axle with three different interference grips is simulated.The evolution of the surface profile and the distributions of contact parameters with fretting cycles were investigated and compared with those of the wheel-solid axle.The result shows that the wear depth of hollow axle is larger than that of the solid axle for given interference grip and load condition.The influences of fretting wear on the the evolution of contact parameters of hollow axle are the same as those of solid axle.The peak value of the contact pressure,the shear stress and the slip amplitude gradually increase with an increase in fretting cycles.The stress concentration occurs at stick-slip boundary.When the wear depth reaches a certain value,the interference grips of worn area are diminished and the stress at worn area is declined.By comparison with the solid axle,the hollow axle has a greater change with the increase of fretting cycles.It is also found that the wear depth of hollow axle is the smallest when the interference grips are a bit larger than the mean value of the standard.