Evolution and formation mechanism of rail corrugation in high-speed railways involving the longitudinal wheel-track coupling relationship

Rail corrugation poses a significant threat to train running safety in the field of railway engineering. Therefore, this study employs numerical analysis to investigate the evolution and formation mechanism of rail corrugation in high-speed railways (HSR). Firstly, a three-dimensional (3D) vehicle-track coupled dynamics (VTCD) model is established, which considers the longitudinal wheel-rail (WR) coupling relationship more adequately. Then, by integrating the USFD wear model into this 3D VTCD model, a long-term iterative wear model is developed to reproduce the corrugation evolution process. The predicted corrugation exhibits two distinct wavelength components and closely matches the sample obtained from China's HSR, validating the established model in terms of reliability. Furthermore, the formation mechanism of these two wavelength components is investigated by analyzing the harmonic behavior of vehicle-track coupled systems (VTCS) and the evolution law of rail corrugation under different calculation conditions. The findings reveal that the 3rd-order vertical rail local bending mode (RLBM) between two wheelsets of a bogie (TW-B) is the primary factor contributing to the formation of the long-wavelength component of rail corrugation. The discrete supports of the fasteners do not affect the 3rd-order vertical RLBM, which can be stably excited. Moreover, the vertical rail vibration has a substantial coupled effect on the longitudinal WR creep. When the 3rd-order vertical RLBM is excited, the coupled effect and the negative longitudinal WR creepage together evidently promote the formation of the short-wavelength component of rail corrugation.