Study on the mechanism for the wheel polygonal wear of high-speed trains in terms of the frictional self-excited vibration theory

In the paper, the frictional self-excited vibration of a wheelset-track system caused by the saturated wheel-rail creep force is proposed as a possible mechanism for wheel polygonal wear of high-speed trains. The wheelset-track system model is established, which consists of a wheelset, two rails, some sleepers and a slab. The stability of the wheelset-track system is studied through the complex eigenvalue method. Results show that the unstable vibration frequency of the wheelset-track system is f= 495.01 Hz, which can lead to the 18th-order wheel polygonal wear. This simulation result is approximately consistent with the field measurement result. Furthermore, the parameters sensitivity analysis shows that increasing the vertical damping of the fastener to a certain extent can suppress or eliminate wheel polygonal wear. In addition, a transient dynamic analysis of the wheelset-track system with the wheelset eccentricity is conducted. Results indicate that the wheelset eccentricity is an important factor affecting wheel polygonal wear. •The saturated creep force can cause self-excited vibration of the wheelset-track system. The dominant unstable vibration frequency from the prediction model is about 495.01Hz, which is very close to the frequency of the 18th-order wheel polygonal wear.•Increasing the damping of the fastener can effectively suppress wheel polygonal wear.•The wheelset eccentricity is an important factor affecting wheel polygonal wear.