Numerical analysis of frictional heat generated between wheel and rail during braking

Abstract

This paper presents the results of numerical analysis of the instantaneous temperature generated by frictional heat on the contact surface between wheel/rail during braking. Damage to the contact surface may occur due to wheel sliding during hard braking in wet conditions. The damage is generally considered to be due to changes in the mechanical properties of the wheel steel under high temperature conditions, however it was not clear to what extent the temperature rises from wheel sliding to wheel sticking. This study focused on the relationship between the temperature rise due to frictional heat generated on the contact surface and the coefficient of friction between wheel and rail, and estimated the instantaneous temperature rise on the contact surface between wheel/rail until the wheel sticks by combining the vehicle dynamics analysis using SIMPACK and the frictional heat analysis we developed. The results of numerical analysis showed that the instantaneous temperature rise on the contact surface generated by friction heat is the highest when the coefficient of friction between wheel and rail is slightly less than its adhesion coefficient, and that the smaller the coefficient of friction between wheel and rail, the lower the instantaneous temperature on the contact surface.