Wheel tread temperature assessment and its impact on rolling contact fatigue under long-term braking conditions

To analyze the temperature rise of the wheel tread under braking conditions and its impact on the rolling contact fatigue (RCF) of the wheels, this paper proposes a numerical analysis method based on thermodynamics, material mechanics, and wheel-rail contact mechanics. This method has features of simplicity and fast computing speed. The study shows that the temperature rise of the wheel tread is mainly affected by the thermal friction between the brake pad and the wheel tread. The effects of track gradient, braking speed, and ambient temperature on wheel tread temperature rise are 16 °C/‰, 9.4 °C/km h⁻¹ , and 10 °C/°C, respectively. Therefore, reducing the gradient of the track, locomotive braking speed, and braking duration can help reduce the wheel tread temperature, thereby slowing the development of RCF of the wheels. The study shows that the value of RCF considering the temperature rise of the wheel tread is about 1.55 times that without considering the temperature rise, while the value of wear damage is reduced by 23 %. Therefore, when analyzing wheel damage, the comprehensive effects of RCF, wear, plastic flow, and temperature are recommended to be considered from different angles to provide a basis for reducing wheel damage.