Study on the Initiation of Fatigue Cracks Due to Wheel-Rail Impact at Insulated Rail Joints

摘要

In this study, we present a method for predicting the initiation of fatigue cracks at insulated rail joints (IRJs). The method includes (1) FE simulation of dynamic wheel/rail interaction at IRJs; (2) analysis on the evolution of wheel/rail contact behavior, and (3) numerical prediction on the initiation life and position of fatigue cracks. To demonstrate the method, we analyzed the crack initiation for a series of rail end intervals. The results indicate that shear loads in the material affects more on the initiation of fatigue cracks at both the surface and subsurface of rail head. Fatigue cracks have a higher likelihood to take place at 0-2 mm below the rail surface of IRJs, with the most dangerous region being at 1 mm below the rail surface. The variation of the rail end interval seldom affects the crack initiation life at the leading rail end of IRJs, whereas it can significantly influence the crack initiation life at the rear rail end.