Influence of a micro-crack on the finite macro-crack

The numerical solution of an infinite elastic plane containing a macro-crack and an arbitrary oriented micro-crack is presented based on the distributed dislocation technique and Gauss-Chebyshev quadrature method, which is verified by finite element method. The stress intensity factor (SIF), stresses field and strain energy density near the macro-crack tip are obtained. The effect of the micro-crack on SIF of the macro-crack is analyzed and the macro-crack propagation direction is predicted based on the minimum strain energy density criterion (SED). The results show that as the micro-crack length decreases or the distance between micro-crack and macro-crack increases, the effect of the micro-crack on SIF of the macro-crack will be getting weaker. The micro-crack increases SIF of the macro-crack at some orientation, while it decreases SIF at other orientation. The micro-crack acts an attraction effect on the macro-crack propagation at some orientation, while it acts a repulsion effect at other orientation.