A probabilistic-statistical approach to the ultimate failure of ceramic-matrix composites—part I: experimental investigation of 2D woven SiC/SiC composites

The strength and reliability of ceramic-matrix composites may be expected to be dependent upon various factors including the size of the stressed volume, the loading history and the loading conditions. The influence of these factors on the strength of 2D woven SiC/SiC composites is examined in this paper. Tensile, three-point flexure and four-point flexure tests were performed on batches of test specimens. Tensile tests were also performed on broken parts of tensile specimens (successive failure tests). The statistical distributions of strength data exhibit important features such as a narrow scatter, no significant dependence on the stressed volume, no dependence on the previous loadings and a certain dependence on the loading conditions. These features are related to the damage mechanisms which limit the contribution of flaws to ultimate failure, and to variability in the local stress-state.