High-speed train axle fretting fatigue scaling experiment research and damage analysis

This work presents the design of a scaled wheel axle fretting fatigue test equipment that takes into account the complicated load boundary conditions of high-speed train axles, which can realize the loading and monitoring of the axle weight load, wheel-rail contact vertical load and lateral load. The scaled wheel axle specimens are processed and assembled, and fretting fatigue tests are performed under varying stress conditions. The results show that the scaled axle's fretting fatigue limit is around 116 MPa under 1 x 10 7 rotational bending load cycles. The power spectral density of the wheel-rail contact load shows a tendency to decrease and then increase with increasing frequency. The crack initiation area, the crack propagation area, and the instantaneous fracture area are all marked by distinct crack propagation traces on the axle's fracture surface. There is noticeable reddish-brown oxidized abrasive debris on the axle interference fit contact edge, block material peeling and delamination on the contact surface, and a tiny amount of wear particles. The primary causes of damage to the axle contact edge area are fretting fatigue-induced delamination and fretting wear-induced material removal.