The inelastic response of porous, hybrid-fiber composites

An effective and efficient three-step micromechanical modeling process for predicting the inelastic thermomechanical response of porous, hybrid-fiber, metal-matrix composites is presented. The three steps include: (1) analysis of a porous, isotropic elastic binder; (2) analysis of an anisotropic, elastic hybrid fiber; (3) analysis of an anisotropic, inelastic metal-matrix composite. Results are presented for axial, transverse and axial shear loading. The degree to which porosity in the binder of a hybrid fiber, filament volume fraction in the hybrid fiber, and hybrid-fiber volume fraction in the composite influence the response is demonstrated for a range of parameters. The influence of thermal effects, including residual thermal stresses and response at elevated temperature is also shown, as are differences in tensile and compressive response in the presence of residual stresses at room temperature. It is concluded that the influence of the parameters is variable, depending upon the type of loading, and that fabrication-induced residual thermal stresses can play a significant role relative to room-temperature response.