Multi-scale modeling and experimental study of fatigue of plain-woven SiC/SiC composites

Abstract

The fatigue life of plain-woven SiC/SiC composites was predicted with the multi-scale method by combining the micromechanical model with the mesoscale finite element model. The micromechanical constitutive relationship of yarns under variable amplitude loading was derived, and the mesoscale finite element model was established by choosing the minimum repeatable unit as the unit cell. The degradation of interface shear stress was obtained by fitting the secant modulus of hysteresis loop, and the fiber random fracture model based on the global load sharing model was adopted to simulate the fatigue failure of the yarns. To improve the prediction speed of fatigue life, the number of fatigue cycles increases exponentially. The fatigue life of plain-woven SiC/SiC composites predicted with the multi-scale method are in good agreement with the experimental results.