YANG Liyun, WANG Qingcheng, WANG Yuwei, XU Longning, SONG Ye, WANG Guidong
The fracture criterion is of great significance in predicting the time, the position and the crack propagation path for materials containing crack. In this paper, the fracture criteria of the linear elastic materials are reviewed, including the common fracture criteria, such as the stress intensity factor criterion, the maximum energy release rate criterion, the maximum tensile stress criterion, the maximum tensile strain criterion and the minimum strain energy density criterion, as well as their advantages and limitations. In view of the insufficient consideration of the stress components and the critical radius in the commonly used fracture criteria, some modified fracture criteria were proposed at home and abroad, including those considering the influence of the T-stress (non-singular term) and the variable critical radius rc. The application of these fracture criteria in brittle materials such as rock and concrete is analyzed. In view of the problems existing in the prediction of the fracture behavior based on these fracture criteria, it is suggested that the propagation path and the deflection angle of the crack can be predicted more accurately when the T-stress, the higher-order term of the stress field at the crack tip, is considered.
