Dynamic Simulation of Axle Box Bearing Fatigue in High‐Speed Rail Systems Incorporating Train‐Track Coupling Dynamics

ABSTRACT Axle box bearings in high‐speed trains serve as critical elements within the transmission system, where fatigue delamination represents a predominant failure mode. To replicate realistic operational conditions, a train‐track coupling dynamic model that includes the axle box has been established. This model integrates essential factors such as track irregularities, wheel–rail contact mechanics, and friction coefficients. The findings indicate that axle box bearings are exposed to multi‐frequency composite loading in actual service environments, with lateral load non‐uniformity markedly exceeding that observed in the longitudinal direction. Fourier transform analysis revealed that the radial load frequency of axle box bearings closely correlates with wheel rotational speed, whereas the axial load demonstrated significant irregularities. Finite element simulation results estimated the crack propagation life of the axle box bearings to be approximately 1.754 × 10⁶ cycles, corresponding to a service distance of roughly 108,200 km. Additionally, key parameters such as the stress intensity factor were obtained, contributing to the assessment of fatigue life under operational loading conditions.