PROGRESSIVE DAMAGE IN CMC MINICOMPOSITES WITH THICK INTERPHASES UNDER TENSILE LOADING [Keynote]

In this work, a composite cylinder assemblage (CCA) model has been used to model the progressive damage behavior under tensile loading of a three-phase ceramic matrix single-tow mini-composite composed of carbon fiber, silicon carbide (SiC) matrix and boron nitride (BN) interphase. A 3-phase shear lag model has been used to capture the matrix crack-driven stress redistribution in the presence of a finite thickness interphase. A probabilistic progressive modeling approach has been proposed to predict the tensile response of ceramic matrix composite (CMC) minicomposites. Multiple matrix cracking, interfacial debonding, and fiber failure have been considered as the damage modes. The predicted tensile response of CMCs from the progressive damage modeling approach agrees with experimental results obtained with C/BN/SiC minicomposites. Finally, the influence of volume fractions, constituent properties, and interfacial properties on the mechanical behavior of CMC minicomposites has been presented.
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