The effect of wheel wear on rail rolling contact fatigue and curve negotiation performance on heavy haul lines

Abstract

With the increase in train load and longer train formations, wheel-rail wear and contact fatigue issues in heavy-haul trains continuously emerge. However, the impact mechanisms of wheel wear in heavy-haul trains on rail Rolling Contact Fatigue (RCF) remain unclear. Therefore, this paper establishes a dynamic model of a C80 freight vehicle, and the advanced discrete elastic contact method is used to calculate the contact parameters. Then, the fatigue index with shakedown diagrams and damage function is used to evaluate the contact fatigue of the rail. This approach analyzes the extent of rail RCF damage under various levels of wheel wear and different wheel diameter differences (WDD), along with its lateral distribution on the rail. Finally, the paper analyzes curve resistance through a curve resistance model. The results showed that the fatigue index and damage under discrete elastic contact are larger than the equivalent elasticity. For worn wheels, the damage to both inner and outer rails increases sharply when the wear depth exceeds 2 mm. Under different WDD values, the maximum damage amount on the larger wheel side increased from 1.42 × 10^-5 to 4.33 × 10^-5. Wheel wear increased the probability and amount of rail RCF, with a more significant increase on the outer rail than the inner rail. The curve resistance increases with wheel wear and decreases with the increase of curve radius, with particularly significant changes between 300 m and 500 m. The findings provide a reference for train operation and the mitigation of rail fatigue.