Linking Coupon to Component Behavior of CMCs in Relevant Service Environment

The goal of the proposal is to develop a physics based modeling methodology and associated software for Ceramic Matrix Composite (CMC) component analysis under aircraft engine hot-section service loading and environmental conditions using coupon test data as input to models.Once developed and thoroughly validated, the methodology would be used in cost effective development of CMC components by the Air Force and its major aerospace suppliers.The proposed methodology is based on a mechanistic (physics-based) model that includes direct consideration of defect and damage mechanisms, and environmental degradation relevant to CMCs.In Phase I the feasibility of using the methodology to analyze CMC components using only experimental data obtained from flat coupons has been demonstrated by comparison with limited amount of experimental data.The proposed Phase II effort aims to extend the applicability of the model to include other issues relevant to aircraft operating conditions, such as general multiaxial loading, delamination, effect of geometric features like ply drop, and effect of fabric wrinkling and yarn waviness.The resulting enhancements will be experimentally validated and demonstrated. The Boeing Company will support the experimental effort as a direct subcontractor.