Simulation of crack propagation in composite materials using cohesive zone model and image-based numerical model

The cohesive zone model is used to simulate the intergranular fracture propagation to get the effects of the microstructure and the interfacial strength on the mechanical properties of the composites. The microstructure morphology of ZrB₂-SiC ceramics illustrated by SEM was imported into ABAQUS finite element software, with the cohesive elements embedded along grain boundaries, to predict the intergranular fracture propagation. The effects of grain boundary and material inhomogeneity on the stress distribution and crack propagation were investigated by changing the ZrB₂-SiC interfacial strength. The result shows an uneven stress distribution and stress concentration are observed due to the presence of grain boundaries. The locations of the crack initiation and propagation direction vary with the interfacial strengths and the crack propagates along the grain boundaries with low strength. The strength of polycrystals increases as ZrB₂-SiC interfacial strength increases, and the elastic modulus remains substantially unchanged.