A chemo-mechanical coupled constitutive model applied to the oxidation simulation of SiC/SiC composite

Herein, a chemo-mechanical coupled constitutive and failure model is proposed to predict the tensile behavior of SiC/SiC composites under oxidizing environments. The diffusion of O-2 through the oxide scale and the oxidation reaction of SiC/O-2 are modeled and implemented in finite element software, through a user-defined element. Numerical validation studies and tests are conducted on a domestic SiC fiber. An orthotropic constitutive model for reinforcements, which considers modulus reduction due to oxidation damage, and a continuum damage model associated with O-2 diffusion along the micro-cracks in the SiC matrix are subsequently presented. The developed framework is used to simulate the mechanical behavior and oxidation process of a single fiber SiC/SiC composite.