Discrete element model for cracking in defective ceramics under uniaxial compression

In this study, an improved discrete element model (DEM) is developed to understand the defect effect in ceramic cracking process. First, model parameters based on the linear parallel bonding model are calibrated using microcell deformation experiments and orthogonal experimental design methods. Then, the uniaxial compression of ceramics with different crack lengths and inclination angles are simulated. The crack initiation and propagation processes are illustrated with displacement and stress fields. The results show the predicted crack patterns are qualitatively in agreement with experimental observations. There are two stages of crack propagation with increasing uniaxial compressive load, i.e., primary and secondary cracks. In addition, the inclination and crack length of the defects have a great influence on the mode of crack initiation and propagation, and the first crack is more likely to initiate and extend for the defects with larger crack length and smaller inclination angle.