Numerical modeling of oxidized C/SiC microcomposite in air oxidizing environments below 800 °C: Microstructure and mechanical behavior

A numerical model is presented for simulation of the oxidation-affected behaviors of continuous carbon fiber-reinforced silicon carbide matrix composite (C/SiC) exposed to air oxidizing environments below 800 °C, which incorporates the modeling of oxidized microstructure and computing of degraded mechanical behavior. This model is based upon the analysis of the representative volume cell (RVC) of composite. C/SiC microcomposite (one single filament) is concerned in the present study. Analysis results of such a composite can provide a guideline for the real C/SiC composite. The microstructure during oxidation process is firstly modeled in the RVC. The stress distributions within the oxidized composite under uniaxial tensile loading are computed by finite element analysis. The failure behaviors of C/SiC microcomposite in air oxidizing environment are evaluated and validated in comparison to experimental data. The oxidation time, temperature and pressure are investigated to show their influences upon the mechanical behaviors of C/SiC microcomposite.