Effects of Coupled Excitation of Wheel Polygonization and Rail Corrugation on Wheel–Rail Dynamic Adhesion Under Wet Conditions

Wheel polygonization and rail corrugation are typical forms of periodic wheel-rail surface damage occurring on metro vehicles. Their interaction produces coupled dynamic excitation that modifies wheel–rail contact behavior under wet, low-adhesion conditions. This paper develops a wheel–rail dynamic adhesion model integrating vehicle–track dynamics, mixed elastohydrodynamic lubrication, and extended creep force theory. Using measured wheel polygonization and sinusoidal rail corrugation as inputs, the model solves the 3D contact geometry via coordinate transformation and analyzes how their coupling affects normal force, tangential force, and the dynamic adhesion coefficient. Results show that low-amplitude polygonization and corrugation mainly excite dynamic load oscillations, with a limited effect on peak contact stress. Yaw angle changes contact point migration and contact patch morphology, causing non-monotonic variations in tangential stress and flash temperature; at zero yaw angle, the adhesion coefficient approaches typical wet-condition levels. Under coupled excitation from measured multi-order polygonization and short-wavelength corrugation, the normal dynamic force fluctuates sharply, frequently causing local transient separation and low-adhesion events, with an average adhesion coefficient of about 0.06. Dynamic adhesion is jointly governed by the load-carrying effect of the water film, the proportion of asperity contact, flash temperature, and the elastoplastic behavior of third-body materials.