Two-Dimensional Crack Inclusion Interaction Effects: Analysis and Experiments

The plane interaction between a crack and a rigid elliptical inclusion is investigated. In particular, the effects of the orientation and aspect ratio of the inclusion are considered. Analytically, the solution for the interaction of a dislocation with an inclusion is used as Green’s function for the problem. The crack problem is then cast in the form of a set of integral equations with Cauchy singularities. These are solved numerically by the use of piecewise quadratic polynomials to approximate the unknown dislocation density along the crack. From this density the stress intensity at the crack tip can be determined. To model the situation experimentally photoelastic specimens with various elliptical inclusions are tested in uniaxial tension. The stress intensity factors are evaluated from the isochromatic fringe patterns and compared to those predicted numerically.