Study on the adhesion behavior of wheel/rail under water conditions by using mixed lubrication model

Abstract

Purpose The purpose of this paper is to propose a wheel/rail mixed lubrication model to study the water lubrication behavior of wheel/rail contact interface. Design/methodology/approach The numerical simulation method is applied in this paper. A deterministic mixed lubrication model considering surface roughness and transient state is established. The quasi-system numerical and finite difference method are used for numerical solution. The model is verified by comparing with the experimental data in the literature under the same conditions. Findings Under wet conditions, the change of train speed will change the lubrication state of the wheel/rail contact interface. With an increasing speed, the average film thickness and the film thickness ratio increase, while the adhesion coefficient, the contact load ratio and the contact area ratio decrease. When the creep ratio increases from 0% to 0.5%, the wheel/rail adhesion coefficient and subsurface stress increase sharply. With the increase of axle load, the average film thickness decreases and the adhesion coefficient increases. Practical implications This paper aims to improve the mixed lubrication theory by analyzing the characteristics of wheel/rail friction and lubrication, so as to provide some guidance and theory for train driving behavior. Originality/value Using the deterministic model, the lubrication state of the wheel/rail contact interface affected by various external factors and the adhesion behavior of wheel/rail progressive process from boundary lubrication to mixed lubrication are studied.