Surface Finish and Notch Effect Model for Strength Predictions of Continuous Fiber Ceramic Composites (CFCCs)

Surface texture and process defects resulting from net-shape machining of continuous fiber ceramic composites (CFCCs) are often ignored in the design and analysis of component parts. Recently a mathematical model was proposed which defines the effects of surface texture and notch effects on the strength of engineering components in terms of an effective stress concentration factor (k_t). This model was experimentally verified using flexural strength resulting for a graphite/bismaleimide laminate. A further verification of the model applied to CFCC materials is presented in here using tensile test results. It was found that the model successfully predicts the retained strength of CFCCs resulting from net-shape machining over a large range in surface quality.