抄録
In this paper, we examine the implicit elasto-plastic calculation algorithm with contact conditions on the crack surfaces in order to obtain stress and strain fields near a crack tip under the biaxial compressive loads. It is important to elucidate the fracture criterions under compressive loads such as the explanation of the existence and the creation of long faults, landslide in slope ground and so on. We find that the mode II crack extension can be explained by plastic effect near a crack tip, and stretch fracture surrounding a plastic crack tip does not occur, especially, the internal friction angle is small. We also find, under the softening plasticity, that deviatoric strain region extends straightly from a crack tip and localizes to narrow band.
