The application of a homogenized overall and local anisotropic damage constitutive model to unidirectional and cross-ply CFCC with oblique loading directions

A homogenized anisotropic damage constitutive model is proposed to describe the mechanical behavior of continuous fiber-reinforced ceramic matrix composites (CFCC) for different loadings direction and laminate stacking sequences. An overall fourth-order damage effect tensor is introduced to account for the overall damage of the composites. In addition, two local (matrix and fiber) fourth-order damage effect tensors are introduced to analyze the local effects of damage experienced in both matrix and fibers. The overall and local damage tensors are correlated through a homogenization procedure. New expressions are derived for the stress and strain concentration factors of the damaged composite. The model is simulated by macro-microscopic finite element method (FEM). As applications of the model, unidirectional and cross-ply CFCC laminates with oblique loading directions are analysed to discuss the effects of fiber arrangement and orientation on the macroscopic mechanical behavior.