Influence of Stress Intensity Factor on Rail Fatigue Crack Propagation by Finite Element Method

Abstract

Wheel rail rolling contact fatigue is a very common form of damage, which can lead to uneven rail treads, railhead nuclear damage, etc. Therefore, ANSYS software was used to establish a three-dimensional wheel–rail contact model and analyze the effects of several main characteristics, such as the rail crack length and crack propagation angle, on the fatigue crack intensity factor during crack propagation. The main findings were as follows: (1) With the rail crack length increasing, the position where the crack propagated by mode I moved from the inner edge of the wheel–rail contact spot to the outer edge. When the crack propagated to 0.3–0.5 mm, it propagated to the rail surface, causing the rail material to peel or fall off and other damage. (2) When the crack propagation angle was less than 30°, the cracks were mainly mode II cracks. When the angle was between 30 and 70°, the cracks were mode I–II cracks. When the angle was more than 70°, the cracks were mainly mode I cracks. When the crack propagation angle was 60°, the equivalent stress intensity factor reached the maximum, and the rail cracks propagated the fastest.

Study of stress intensity factors in sliding and tearing modes for subsurface elliptical cracks in rolling train wheels

“…7 Obtained data showed that under the mixed mode II + III loading, the cracks initiate from the interior parts of the wheels under the stress state with the shear plastic strains and high normal compressive stress. Gao et al 8 numerically studied the fatigue crack growth in the railway wheels and determined the effects of some parameters such as crack angles and lengths on the mixed mode growth. Yan et al 9 investigated the mixed modes I + II crack growth in the wheels and found the influence of variations of the wheel roundness conditions on the fatigue lives.…”