DELAMINATION FRACTURE IN CERAMIC MATRIX COMPOSITES: FROM COUPONS TO COMPONENTS

Delamination fracture can occur in complex-shaped Ceramic Matrix Composite (CMC) components due to a combination of high interlaminar stresses and low interlaminar strength and toughness. In this paper, delamination propagation in SiC-based CMC is studied using experiments and corresponding computational modeling. Room-temperature Double Cantilever Beam (DCB) testing was conducted to study mode I delamination propagation. Cohesive-zone finite element analyses were conducted to explain the experimental data and to extract delamination cohesive-zone parameters. The extracted parameters are then used to analyze a representative complex geometry and results compared against corresponding experimental data. It is shown that accurate modeling of the crack growth resistance behavior is essential for consistent modeling of delamination behavior ranging from simple coupons to complex sub-element/components.