In the railway systems, induced contact between wheels and rails creates maximum shear stress around the contact surfaces. These shear stresses vary with the wheel's rolling and can initiate and extend subsurface cracks in the wheel and rail. The most common subsurface cracks in the rail systems have elliptical forms. Sliding and tearing modes of the fracture can be observed due to different components of the shear stresses around the contact area. Com- pressive normal stress has no considerable effects on in-plane and out-of-plane shear modes for subsurface cracks. In this research, by proper modeling of the wheel and rail, the effects of dimensions, position, and depth of the subsurface cracks on the stress intensity factors of the sliding (K II ) and tearing (K III ) modes have been investigated. Also, variations of the K II and K III values versus wheel rolling angles and frictions have been considered. The validity and accuracy of the cracked model created by sub-modeling technique have been verified by half-space modeling and weight function method.
