碳/碳多孔防热复合材料压缩性能研究

常见高性能热防护材料的力学性能较为薄弱,这成为了飞行器热防护系统发展的瓶颈。因此,如何设计热防护材料,使其具有良好隔热效果同时兼具足够的承载能力,成为当前的研究热点。本文针对碳/碳多孔防热复合材料进行了单轴压缩实验,获得了其压缩应力—应变曲线,研究了其压缩变形特征及相应的失效模式,并通过SEM观测变形前后的材料细观结构,分析了材料内部的细观变形机制,也为进一步建立表征材料内部细观结构特征的有限元模型和进行数值模拟研究奠定了实验基础。实验结果表明:材料内部纤维主要沿面内随机分布,呈现出明显的分层现象。受其结构的影响,该材料面内方向力学性能比厚度方向优越。

Compressive Properties of Porous C/C Thermal Protective Composites

Common high-performance thermal protection materials have relatively weak mechanical properties, which became the bottleneck of aircraft thermal protection system development. Therefore,to design thermal protection materials with both good insulation effect and enough load capacity the become current research hot spots. In this paper, the stress-strain curve of the C/C thermal protective composite (C/C composite) was obtained by the uniaxial compressive experiments in order to investigate the compressive deformation and fracture model of C/C composite. Moreover, the microscopic morphology and microstructure deformation of this material were also studied by the SEM observations of the original material and fracture section, which also provide an experimental foundation for the characterization of the internal microstructure to establish the numerical geometric model and FEM simulation. The experimental results show that the fibers in C/C composite are randomly distributed along in-plane direction, which cause the obvious stratification. The mechanical properties of C/C composite in the in-plane direction are superior to those in the out-of-plane direction.