Study on crack propagation based on extended finite element and optimized adhesion structure

The basis of numerical simulation in this paper is discontinuous finite element analysis named extended finite element method. The description of the theory is helpful to understand the basis for the realization of cohesive constitutive relation in software. The characteristics of linear cohesive constitutive relation, bilinear cohesive constitutive relation, turning point and implicit function cohesive constitutive relation are studied. A new cohesive constitutive relation is optimized with analysing the advantages and disadvantages of each cohesive constitutive relation. Comparing the experimental results of classical mode I crack propagation with the numerical simulation of the cohesive constitutive relationship, show that the simulation results of the optimized constitutive relationship are closer to the experimental structure than those of the bilinear constitutive relationship. Optimized cohesive constitutive model is used to simulate an asymmetric four-point bending beam with a single notch. The results show that the crack propagation trajectory is highly consistent with the experimental structure. The rationality of optimizing the cohesive constitutive relation is verified by comparing two experiments.