Interaction of a main crack with ordered distributions of microcracks: A numerical technique by displacement discontinuity boundary elements

A boundary element technique, based on a pure displacement discontinuity formulation, is presented to solve general problems of interaction between cracks. The procedure allows detailed information and high precision at the expense of a reasonable computational effort. The comparisons with exact solutions and numerical ones for elementary case show a good performance of the method in the case of strong interacting cracks too. The interaction of a main crack with some microcrack arrays is studied in terms of amplification and shielding of the SIF at the main crack tip. The analysis of the results shows that, while shielding can be considered a short range phenomenon, amplification has a wider range involving more distant microcracks; this fact fits well with some experimental investigations given in the literature.