C/SiC编织复合材料的热-力-氧耦合理论与三维几何重构方法

The excellent properties of the C/SiC braided composites, such as high strength, low density and high temperature endurance, make it an ideal material for thermal structure in aerospace industry. So it is of great theoretical significance and application value to conduct comprehensive research on the thermal mechanical oxygen coupling property and 3D geometrical reconstruction method for the defected materials. Due to the complex manufacturing technology and rigorous service condition, the material failure is synthetically induced by its interior micro/mesco structural property and the coupling effect of thermal mechanical oxygen factors. But recently no mature theoretical model and geometrical reconstruction method have been developed for the C/SiC braided composites when considering the coupling effects of the thermal, mechanical and oxygen factors, especially for the materials with true defects. Basing on the theoretical analysis, numerical simulation and experimental methods, this project aims to propose an accurate 3D geometrical reconstruction method to establish a model for C/SiC braided composites with true defects firstly; and then considering the damage effect, to propose a thermal mechanical oxygen coupling model and accordingly the finite element model. The achievements of this project can provide theoretical foundation and technology supporting for the wide application of the C/SiC braided composites in aerospace industry.

C/SiC编织复合材料具有强度高、密度低且耐高温等优点成为航空航天领域热结构理想材料之一。研究含缺陷材料的热/力/氧耦合理论与几何重构方法具有重要科学意义和应用价值。由于C/SiC编织复合材料特殊的制备工艺和苛刻的服役环境，材料发生失效是其自身微、细观结构特性与热、力、氧等因素耦合作用的结果。然而，对该材料的三维几何重构建模算法和热/力/氧耦合损伤理论的研究还不成熟，尤其缺乏含真实缺陷特征的C/SiC编织复合材料热/力/氧耦合有限元数值分析方法。本项目采用理论分析、数值计算和实验验证相结合的方法，拟提出C/SiC编织复合材料精细化三维几何重构建模算法，实现含真实缺陷特征的C/SiC编织复合材料几何建模；并提出热/力/氧耦合损伤本构模型，据此建立含真实缺陷特征的C/SiC编织复合材料的热/力/氧耦合有限元数值分析方法。该方法可为C/SiC编织复合材料在航空航天领域应用提供理论基础和技术支撑。

C/SiC编织复合材料具有强度高、密度低且耐高温等优点成为航空航天领域热结构的理想材料之一。研究热-力-氧耦合损伤理论及含缺陷材料的热-力-氧耦合损伤数值分析方法具有重要科学意义和应用价值。由于C/SiC编织复合材料特殊的制备工艺和苛刻的服役环境，材料发生失效是其自身微、细观结构特性与热、力、氧等多种因素耦合作用的结果。然而，对该材料的热-力-氧耦合损伤理论的研究还不成熟，尤其缺乏含真实缺陷特征的C/SiC编织复合材料热-力-氧耦合有限元数值分析方法。本项目采用理论分析、数值计算和实验验证相结合的方法，首先，基于CT扫描技术，建立C/SiC编织复合材料三维几何重构算法，其次，基于连续介质损伤理论，建立C/SiC编织复合材料的力学损伤本构关系；并通过考虑C纤维和SiC基体在不同温度环境下的氧化机理，将能量法与氧化动力学相结合来建立高温氧化腐蚀对结构力学性能影响的理论模型；最后，基于热力学原理建立C/SiC编织复合材料的热-力-氧耦合损伤本构关系。在此基础上结合C/SiC编织复合材料的缺陷微细观统计特征方法，提出含缺陷特征的C/SiC编织复合材料的热-力-氧耦合有限元数值分析方法。该方法可为C/SiC编织复合材料在航空航天领域的应用提供理论基础和技术支撑。