Damage-based failure theory and its application to 2D-C/SiC composites

Damage evolution is of great importance to determine the final failure of ceramic matrix composites (CMCs). In order to characterize the damage coupling behavior and its effect on failure strength of CMCs, a new methodology for damage coupling analysis was formulated. And, new kind of damage-based failure criteria were established under plane stress state, including maximum damage criterion and quadratic damage criterion. Both the criteria require investigation upon the damage evolution laws. The proposed failure theory was applied to predict the coupled damage behavior and the off-axis strength of a 2D C/SiC composite. The theoretical results agree well with the experimental data.