A damage constitutive model for the nonlinear mechanical behavior of C/SiC composites during mechanical cyclical loading/unloading

In this study, the nonlinear mechanical behavior and corresponding damage mechanisms of C/SiC composites during cyclic loading/unloading tensile tests were studied. Besides, based on composite microstructure mechanisms, evolution model single fiber unit are proposed to explain stiffness degradation, inelastic deformation accumulation, elastic deformation. According degradation law, Weibull failure probability is established, which can fit damage-strain curves well. Additionally, considering microscopic matrix cracking, interfacial debonding, sliding established. model, stress distributions before after loading unloading analyzed obtain strain formulas that perfectly experimental results (R2 > 99.9%). Because reflects in a much more simplified way, law be well predicted with basic macroscopic parameters such as composition composite, modulus fiber, matrix, strength residual thermal matrix.