Continuum damage mechanics-based finite-volume homogenization of unidirectional elastoplastic fiber-reinforced composites

The Finite-Volume Direct Averaging Micromechanics (FVDAM) method has been further extended to predict nonlinear behaviors of unidirectional boron/aluminum (B/Al) composites, induced by plastic deformation and ductile damage for the first time. The latter is considered by gradual stiffness degradation via the continuum damage mechanics (CDM) model. The convergence of homogenized and local response generated by the new FVDAM damage framework has been demonstrated by considering the hexagonal and square repeating unit cells (RUC) with different mesh discretizations under transverse tensile, transverse shear and axial shear loading paths. Then, the reliability of the developed approach to predict the nonlinear response of B/Al composites has been verified extensively vis-à-vis the experimental response available in the literature, under monotonic loading path with various off-axis angles. To accurately capture the experimental response, an RUC with actual microstructure characterized by a random fiber distribution is constructed and utilized in the numerical simulations. In addition, the developed model is also applied to predict the cyclic response of B/Al composites with different off-axis angles in further support of the theory’s potential to capture the macroscopic behaviors of B/Al composites under complex loading conditions.