Research Of Fretting Fatigue On Railway Wheel-Axle Assembly

Railway axle is one of the most critical components for railway vehicle. It would cause the train derailed, overturned and other major fatal accidents if axle was broken. The fatigue failure usually occurs in the axle shaft and axle wheel seat. It is more dangerous for fretting fatigue damage at the axle-wheel seat as it is more difficult to detect.This paper investigated the fretting fatigue properties of 35CrMo steel by a PQ-6 rotating bending fatigue testing machine. With the finite element software, ANSYS, the influence of the contact pressure and friction coefficient on the size of fretting zone and fretting slip amplitude is studied. Ruiz parameter and SWT parameter are used to predict the location of the initiation of fretting fatigue crack. To predict the initiation life of fretting fatigue crack, SWT parameter is employed. The results are as follows:It tells by the result of fretting fatigue tests that the fatigue strength of fretting is reduced dramatically compared with that of plain fatigue strength. The oxides and scars in the surface indicate that friction and wear behaviors take place. The fretting fatigue crack initiated around the contact edge.Contact pressure and the friction coefficient have influence on fretting fatigue life. The size of fretting zone and fretting slip amplitude increases with increasing the contact pressure and the friction coefficient.Ruiz parameter and SWT parameter are useful to predict the location of the initiation of fretting fatigue crack. SWT parameter is helpful to predict the crack initiation life of fretting fatigue.