Modeling of stress transfer in fiber-reinforced ceramic matrix composites

An analytical model and a finite element analysis (FEA) have been performed to investigate the stress distribution in fiber-reinforced ceramic matrix composites (CMCs) subjected to temperature changes and uniaxial tensions. The analytical model satisfies all equations of equilibrium, all stress-strain-temperature relations, all except two boundary and interface conditions in either an exact manner or an average sense. The stresses, strains, and displacements in discontinuous as well as continuous fiber-reinforced composites can be obtained. The present FEA is focused on the effects of microstructure, such as fiber and matrix properties, matrix dimensions, and fiber aspect ratio, on the stress transfer in discontinuous fiber-reinforced CMCs. Furthermore, the effects of fiber coating properties and thickness on the stress transfer in continuous fiber reinforced CMCs are analyzed. The results of the present FEA have been compared with those of the present analytical and the modified shear lag models. The results of analytical models agree with those of FEA quite well except at the fiber end region.