Numerical solution of stress intensity factor in an infinite plate containing parallel double cracks under compression and shear

The Fredholm integral equation method and the superposition principle are applied to solve the equations for the problems of collinear double cracks and non-collinear parallel double cracks in an infinite plate under compression and shear. The numerical solutions of the proposed method are verified by the analytical solutions of the elliptic integral method. Then the effects of geometrical position of two cracks and friction of crack face on the interaction between two cracks are investigated, and the calculated results of stress intensity factors at the tips of parallel double cracks under compression and shear are provided. The influences of crack spacing, crack half-length ratio and rock -bridge dip angle on the distribution of perturbation stress on the crack face are discussed, which are not reported previously.