Influence of wheel hollow wear on wheel–rail contact behavior under wet conditions with consideration of yaw angle

During rainy conditions, the formation of a water film on the rail surface substantially reduces the adhesion coefficient due to lubrication effects, with hollow-worn wheels being particularly susceptible to this phenomenon. This study develops a three-dimensional dynamic adhesion model that incorporates yaw effects to investigate the rolling contact behavior of hollow-worn wheels under wet conditions. The proposed framework integrates a non-Hertzian elastohydrodynamic lubrication model for normal contact analysis and an extended creep force model for tangential behavior, with dynamic inputs provided by a vehicle–track coupling dynamics model. Results demonstrate that the contact pressure and film thickness exhibit distinct non-Hertzian characteristics, successfully capturing the two-point contact behavior induced by hollow wear. With increasing operating mileage, hollow wear depth grows while the adhesion coefficient declines consistently. Furthermore, yaw angle amplifies lateral displacement during two-point contact, deteriorates the wheel–rail contact state, and further reduces adhesion. Two-point contact fundamentally alters the subsurface stress regime by driving the peak von Mises stress deeper into the material while reducing its magnitude through load distribution, consequently modifying the material's fatigue response. These findings provide critical insights into the adhesion degradation mechanisms and a theoretical basis for maintenance optimization of hollow-worn wheels in wet environments.