Effect of wheel polygonal wear on axle fatigue life

During prolonged high-speed operation, wheels can develop uneven circumferential wear, leading to out-of-round conditions that exacerbate wheel-rail interactions. As a critical component of high-speed trains, axles bear significant loads, making accurate fatigue life assessment essential for safe operation. This study examines the impact of polygonal wheel wear on the fatigue life of high-speed train axles. Using a specific high-speed train wheelset model, a rigid-flexible coupling dynamic model was established to account for wheelset flexibility. Dynamic stress at key axle positions was calculated using the modal stress recovery method and validated via the finite element method (FEM). This study investigated the influence of polygonal wheel wear on axle bending stress and assessed fatigue life at critical axle points using the nominal stress method. Results indicate that polygonal wheel wear amplitude significantly affects bending stress ranges at key axle positions. Bending stress induced by polygonal wheel wear shows nonlinear characteristics with increasing vehicle speed. Under different polygonal wear orders, axle stress variation peaks at 173 Hz, 270 Hz, 580 Hz, 690 Hz, and 930 Hz, corresponding to wheel-rail coupled vibration modes. Fatigue damage at axle points increases with the amplitude of polygonal wheel wear, with the highest damage observed in the transition zone between the gearbox seat and wheel seat. This damage value is 0.56 under a 0.2 mm polygonal wheel wear amplitude, meeting design requirements.