Abstract
Numerical simulation method for analyzing the fracture behavior of brittle materials was developed on the basis of the initiation of micro-cracks. Deformation and the fracture behavior of porous ceramics with initial cracks were numerically simulated. The mean stress model was adopted as the condition of the initiation and propagation of micro-cracks. The micro-cracks were located in a regular manner as the bonds of a square lattice. The stress distribution and stress intensity factors at micro-crack tips were calculated numerically by the body force method(BFM). As the variance of the critical strength increased, and as the initial crack length became long, the stress-strain relationship became nonlinear. When the initial crack length was small, the fracture occurred not from initial crack tip. The size of the non-damaging defects could be evaluated by the proposed method. The resistance curve calculated was independent of the initial crack length. The calculated results agreed very well with the experimental results.
