CRACK INTERACTING WITH AN INDIVIDUAL INCLUSION BY THE FRACTURE CRITERION OF CONFIGURATIONAL FORCE

Based on the concept of configurational force, a new fracture criterion is proposed to determine the crack initiation and the direction of crack propagation. The criterion assumes that when the resultant configurational force reaches a critical value, the crack begins to grow, while the direction of the crack propagation is the vector direction of the resultant configurational force. Moreover, the finite element method of configurational force is developed to realize the numerical simulation of crack propagation. The crack propagation problem of the structure with an individual hole/inclusion in engineering is studied. The results show that the crack propagation criterion based on configurational force can predict the crack growth interacting with an individual hole/inclusion well, the results of the numerical simulation are consistent with experimental results, which verifies the validity of the simulation method of the crack propagation. The numerical simulation of the interference between cracks and inclusions (holes, soft inclusions or hard inclusions) shows that the inclusion near tip of the crack has an important influence on the propagation of the crack. The propagation direction of the crack is related to the relative position of crack and inclusion, and the type of inclusion. The soft inclusion and the circular hole attract the crack to expand, while the hard inclusion will repel the crack growth, and the crack will bypass the hard inclusion during the propagation. When the intersection angle of the crack and inclusion is small, the effect of inclusion on crack propagation is obvious. The inclusion has little effect on crack propagation when the angle is large. Particularly, when the angle is 45°, and the growth of soft inclusion may suppress the crack propagation. This study can help to understand the crack propagation in the structure with voids and inclusions, and have important guiding significance for the fracture problems in engineering.