Thermal and mechanical characteristics of contact friction pair based on 3-D wheel/rail-foundation contact vertical system

The main goal of this article is to analyze the influence of wheel/rail friction heat on the wheel/rail contact friction pair. The nonlinear constitutive relation and heat conduction equation are established firstly. In addition, a direct coupling model of 3-D wheel/rail-foundation contact vertical system is established. The mechanical, thermal and geometrical characteristics of wheel/rail friction pair are researched. The results show that the temperature rise on the wheel/rail contact surface is significant, and the influence of friction heat on the contact patch, contact pressure and stress is obvious. However, the influence focuses on the surface and subsurface of the wheel/rail contact. Once the depth reaches certain distance below the contact surface, the influence can be ignored. The temperature does not change when the distance to the rail surface surpasses 3.28 mm; also the influence of temperature rise on the stress becomes very weak when the distance exceeds 8.05 mm.