Numerical investigation of wheel-rail adhesion using a simplified three-dimensional model considering surface roughness and temperature

Wheel-rail adhesion is important to the traction and braking of railway vehicles. This paper develops a three-dimensional numerical model considering surface roughness and temperature to investigate water-contaminated adhesion characteristics. A simplified elastohydrodynamic lubrication model considering the thermal effect is developed to obtain the normal load carried by liquid film and asperities. Meanwhile, a third body layer (3BL) model, which considers the effects of pressure and temperature on 3BL, is used to calculate the tangential stress and friction coefficient of asperity contact. To verify the numerical model, firstly, the results are compared with the existing experimental results at low and high speeds. In addition, the effects of surface roughness and temperature on adhesion coefficient are investigated. Furthermore, the elastoplastic behaviour of the tangential stress and the adhesion characteristics for large creepages are studied. The obtained adhesion-creepage curve can represent the decreasing trend after reaching saturation because of temperature.