A method of discrete crack growth analysis for quasi-brittle materials and numerical study of mixed-mode fracture of concrete

In this paper, we develop a FEM-based method for the analysis of discrete crack growth in quasi-brittle materials, and apply it to a numerical study on the fracture behavior of concrete under mixed-mode loading. The method is based on the discrete crack model for representing the generation and propagation of fractured surfaces in conjunction with the cohesive crack model for modeling the quasi-brittle softening behavior. Also, arbitrary discontinuities are realized by a mesh-realignment technique. After formulating the problem with the cohesive crack model and presenting the techniques for representing arbitrarily evolving discontinuities, we demonstrate the capability of mesh-size independency and the applicability to deterioration problems of heterogeneous solids due to cracking. Finally, the fracture behavior of concrete is numerically studied by performing a benchmark test characterized by mixed-mode fracture, which is called Nooru-Mohamed Test.