Abstract：Under the action of cyclic rolling contact load, the problem of cracks on rail surface frequently occur, which seriously threatens the operation safety of high-speed trains. Therefore, it is of great significance to carry out 3D rolling contact fatigue crack propagation analysis on rail surface. Firstly, considering different initial crack angles, a three-dimensional finite element model of rail with initial cracks was established. Cyclic rolling contact load was applied to the rail surface to calculate rolling contact between wheel and rail. Then, the stress intensity factor of the crack front is calculated based on the interaction integral method. Finally, the maximum tangential stress criterion and Paris’s law are used to calculate the crack growth direction and growth rate in the current state, and then the crack shape and size at the next moment are updated. By repeating the above process, the propagation path of the three dimensional crack on the rail surface is predicted. The analysis of the SIF at the crack front during the cyclic rolling loading shows that, with the increase of the initial crack angle, the peak values of KⅠ and KⅡ decrease and increase, respectively, and the equivalent SIF at each position of the crack front decreases gradually. When the node at the crack front is closer to the rail surface, the equivalent SIF is larger. The calculation results of crack propagation show that with increasing the number of cycles, the cracks with different initial angles are deflected and gradually expand towards the rail depth direction. The larger the initial crack angle is, the more cycles are required for the propagation. The evolution curves of crack length with the number of cycles under different initial crack angles were calculated, and it was found that the smaller the initial crack angle is, the higher the crack growth rate is.
2023, Vol. 44 
