Defects and Damage in Ceramic Matrix Composites (CMCs) Impact on Material Performance

Innovative research and development leading to a dual-use advanced technology product is proposed. The product is a methodology and associated software for a damage-based non-linear deformation model to study the effect of manufacturing defects and service-induced damage in Ceramic Matrix Composites (CMCs). Once developed, the model would be used in conjunction with non-destructive evaluation (NDE) methods to predict the effect of defects and damage on structural properties, component life and residual strength. The primary focus is on 2D SiC/SiC HiPerComp CMC for the gas turbine components. However the methodology would be applicable to a much broader class of CMCs and components for military and commercial applications. An innovative Physics-Based mechanistic modeling approach is proposed. The approach includes direct consideration of relevant defect and damage mechanisms and environmental degradation. Phase I will involve characterization of the mechanistic model for CMC materials selected by Pratt & Whitney for exhaust nozzle application. The models will be validated against already available test data and against test data generated by our partner, Triton Systems, Inc., under Topic AF103-153. Predictions will be compared with experimental measurements to assess the modeling approach and feasibility for a comprehensive methodology development in Phase II. The proposed product is a comprehensive defect and damage assessment methodology and associate software for its implementation. BENEFIT: Due to the proliferation in potential applications of ceramic matrix composites in military and commercial aerospace engines and in industrial gas turbine industries, the proposed dual-use high technology product has an immediate and expanding market. SAI will market the methodology, the software and technical expertise (services) to these and other industries.