Stress fields in composites reinforced by coated cylindrically orthotropic fibers

Local fields and effective thermoelastic properties are derived for coated fiber composites with cylindrically orthotropic fibers and transversely isotropic coating and matrix phases. Thermomechanical loading situations are considered in which a uniform stress and a uniform temperature change are applied to the boundary of the composite aggregate. A micromechanical model, based on the Mori and Tanaka's concept of average stress in the matrix, is used to account for phase interaction. It is found that a special treatment is needed in formulation of effective properties of composites reinforced by constituents which are curvilinearly anisotropic. Results are presented for a pitch precursor carbon fiber, carbon coating and titanium aluminate matrix system.