极端环境下碳纤维增强复合材料结构的力学行为表征与评价

由于先进复合材料在航空航天器领域具有极其广泛的应用前景，同时考虑到航空航天飞行器需要服役在低温环境下，因而研究低温环境下先进复合材料的力学行为及性能是非常必要的。首先，本项目拟针对低温环境作用下的先进复合材料结构的表面变形问题，构建一套数字图像测试系统。其次，利用该系统研究层压结构和夹层结构复合材料表面的微裂纹扩展及损伤演化机制，分析受冲击作用的材料损伤容限。再次，建立低温环境下复合材料静载和冲击有限元模型并与实验结果进行对照，最后，构建先进复合材料结构在低温环境下受静载和冲击载荷的力学模型，并建立相应的损伤破坏准则。

Advanced composite structures have been increasingly used as structural members in many structures such as missile, airplane, satellites et al. Hence, it is necessary to characterize and evaluate the mechanical behaviour of advanced composite structures used in airplane under its service environment, which in fight condition undergoes low temperature. In our project, a new measurement system based on Extended Digital Image Correlation system will be established to measure the deformation of the surface of the advanced composite structures under temperature at -60 C. Then,the mechanical behaviour of advanced composite structures and the onset and the evolution of the surface micro-cracks of the material will be investigated using this new measurement system. Further, the impact behaviour and the remaining load carrying capacity after impact for the advanced composite structures under low temperature will be investigate. Third, the FE model for simulating the static and impact behaviour of advanced composite structures under low temperature will be established and the FE model will be validated by the experimental results. Finally, the mechanical model for advanced composite structures under statics load and impact load at a low temperature will be developed and the damge model for this structure will also be established.