Calculation of the stress intensity factor for a semi-elliptical surface crack on a rotating compressor blade

Propagation of a semi-elliptical crack on the suction surface of a rotating blade of a gas turbine compressor is modeled and analysed. The analytical solution for the stress intensity factor (SIF) at the deepest point of the crack shows that the SIF increases with an increase in the crack depth and rotation speed, whereas the SIF decreases with an increase in the semi-elliptical aspect ratio and crack-rotation axis distance. The SIF increase rate with increasing crack depth is found to depend on the aspect ratio. Comparisons of theoretical and numerical calculation results reveal a relative error within 4%. The SIF distribution along the semi-elliptical surface crack front at different depths, positions, and aspect ratios are obtained by a numerical method.