An innovative wheel rail wear model under conformal contact conditions

Wear at the wheel–rail interface is a key factor affecting vehicle safety, dynamics, and maintenance strategies. The progressive modification of wheel and rail profiles due to wear can significantly influence stability, comfort, and operating costs, making accurate prediction of profile evolution essential. Traditional wear models often rely on simplified flat-contact assumptions, such as those in the FASTSIM algorithm, which fail to capture the real behavior under conformal contact conditions typical of worn surfaces, curves, and flange–rail interactions. This study proposes a wear model integrating a conformal contact formulation by extending the Kik–Piotrowski normal contact model with Blanco–Lorenzo’s coefficients and enhancing FASTSIM to handle non-elliptical and curved patches in the tangential problem. Implemented within a Simpack Rail multibody framework, the model reproduces realistic operating conditions. Comparisons with conventional non-conformal models highlight that the proposed approach achieves a superior balance between computational efficiency and physical accuracy, providing a more reliable tool for wear prediction and maintenance optimisation in railway systems.