Effects of Void Defects on Fracture Features and Tensile Strength of C/SiC Composites: an Image-based FEM Study

Manufacturing defects in ceramic matrix composites (CMCs), such as voids, microcracks, etc., significantly affect the damage events and strength of the materials. This study aims to reveal the effect of void defects on the failure behavior and tensile strength of a plain-woven C/SiC composite. The mesoscopic architectures of the C/SiC composites are tested by micro-computed tomography. Based on the μ-CT images of the material, finite element models (IB-FEM) of the C/SiC composite are established with different void volume fractions and different void geometry. The tensile strength and fracture features of the C/SiC composites are calculated by using the IB-FEM. The effects of void volume fraction and geometry on failure behaviors and tensile strength of the C/SiC composites are investigated and discussed. This study is of great significance for further understanding the influence of defects on the mechanical behavior of CMCs.