Thermal Analysis of Wheel‐Rail Contact Under Brake‐Induced Sliding Conditions

ABSTRACT The high frictional temperature generated during brake‐induced sliding significantly alters both the friction environment and material properties of the wheel‐rail system, serving as a critical factor affecting adhesion performance and inducing wheel‐rail failures. Through systematic analysis of the heat transfer mechanism at wheel‐rail contact interfaces, a heat conduction equation, along with an equivalent heat source model, was established. By applying Laplace transformation techniques, an analytical method was developed for calculating wheel‐rail temperature. Thermal analysis was performed by systematically incorporating four critical parameters: slip ratio, running speed, friction coefficient, and wheel load. The results demonstrate that surface temperatures increase proportionally with slip ratio, speed, and friction coefficient. Specifically, under braking conditions, the wheel exhibits both higher surface temperatures and steeper temperature gradients relative to the rail as the slip ratio increases. Moreover, although surface temperatures and their spatial extent increase with wheel load, the primary influence occurs through heat flux changes rather than contact area alterations, as the latter's effect is limited.