A mixed mode rock fracture model for the prediction of crack path

Crack propagation in rocks is simulated by using a displacement substitution method based on a mixed mode fracture criterion. The main advantage of this model is that it can distinguish between mode I and mode II stress intensity factors simultaneously. A typical finite element program is used to compute displacements adjacent to the crack tip. The maximum circumferential tensile stress is adopted as a 'yield surface' for the calculation of the load factor in each crack increment. Pure mode I and mixed mode examples have been analysed to validate the capability of the model. Copyright (C) 1999 John Wiley & Sons, Ltd.