Stress intensity factors around a 3D squat form crack and prediction of crack growth direction considering water entrapment and elastic foundation

In this paper, the stress intensity factors (SIFs) around a 3D semi-elliptical squat on a rail surface are investigated. Elastic foundation and water trapped inside the crack are considered as key factors in crack propagation. It is found that the opening mode and shear modes show different behavior compared with former models. Also the lateral load can change the SIF pattern significantly. The superposition traction ratio and lateral load can increase the equivalent SIF up to 200%. This study confirms the pressurized water in a crack changes crack propagation direction making a squat.

► Stress intensity factors (SIFs) at a crack tip on a rail surface are estimated considering governing parameters.
► Sensitivity of SIFs to rail and 3D crack geometry is shown.
► Water entrapment is modeled and it is shown the crack growth direction angle depends on that.
► The growth angle is estimated when a wheel passes the crack at a realistic condition.
► A case study is performed on a severe squat.