Anisotropic micromechanical creep damage model for composite materials: A reduced-order approach

An anisotropic micromechanical model aimed at characterizing the response of composite material to creep is presented. The constitutive model of microconstituents is based on the Kachanov-Robotnov creep damage model for isotropic materials. An anisotropy of the model is introduced through homogenization, which derives macroscopic properties from micromechanical properties of microconstituents. A reduced-order micromechanical model is formulated to substantially reduce (up to several orders of magnitude) the number of unknowns in the microscopic problem compared to the direct homogenization approach. The reduced-order model is based on the reduced-order homogenization with eigen-strains, which describes the inelastic part of the microscopic displacement field by means of eigen-deformations. An adaptive algorithm has been devised to evaluate the time step needed to ensure solution accuracy. Numerical studies are presented to demonstrate the efficiency of the model.