碳化硅纤维增强碳化硅基复合材料的疲劳行为模拟分析

The continuous carbon fiber reinforced silicon carbide matrix composite (SiC_f/SiC) has become an important thermal structural material for the next generation of aerospace engines due to its advantages of lightweight, high-temperature resistance, and high damage tolerance. However, the long fatigue test cycles and high costs severely limit the in-depth understanding and engineering applications of complex microstructures of SiC_f/SiC. To fully exploit the advantages and tunability of SiC_f/SiC, and to achieve the prediction of structural load response and optimization design, this study analyzed the fatigue life curves of unidirectional, orthogonal, and two-dimensional braiding SiC_f/SiC using fatigue hysteresis models and progressive damage theory. The sensitivity evaluations of SiC_f/SiC fatigue life were achieved by adjusting parameters such as interfacial shear stress (±20%), fiber strength (±5%), fiber Weibull modulus (±1%), and fiber volume fraction (±5%) through bias processing. The resulting upper and lower bounds of the fatigue life curves enveloped the primary experimental results.