Defect and Damage Assessment Methodology for CMC Components

Innovative research and development leading to a dual-use advanced technology product is proposed. The product is a methodology and associated software for defect and damage assessment of ceramic matrix composite (CMC) components. Once developed, the model would be used in conjunction with non-destructive inspection (NDI) methods to predict the effect of defects and damage on component life and residual strength. The primary focus is on CMCs for the JSF exhaust system 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 benchmark and sub-element test data. 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