Crack Growth of Non-Coplanar Parallel Crack Array and Tension-Softening Model(Brittle Fracture)

Abstract

It is well known that the tension-softening model can describe the macroscopic fracture behavior of quasi-brittle materials containing pre-existing microcracks such as rocks, ceramics and concretes. The problem studied in this paper is a tension-softening behavior in brittle materials based on the growth of a non-coplanar parallel crack array. Crack growth analyses are performed numerically using the body force method. The problem calculated is a non-coplanar crack array subjected to uniform tensile stress at infinity. The plane strain condition is assumed. The maximum principal stress criterion is employed to determine the each crack growth direction and the global stress required for crack propagation. The tension-softening behavior is studied from the remote tensile stress and deformation of the numerical result. The deduced tension-softening curve is consistent with experimental data obtained for granites. This evidence revealed that the overlapping of non-coplanar cracks, i.e. the ligamentary bridging, is the main source of the tension-softening behavior of granites.