单向碳／碳复合材料的蠕变内应力

用应力降落法测定单向ＰＡＮ基碳纤维Ｔ３００增加热碳基复合材料在１９００－２３５０℃蠕变内应力σ０，结果及分析表明，对单向Ｃ／Ｃ复合材料，σ０不是一个材料常数，而是温度Ｔ、初始力σｓ及结构因子Ｓ的函数，即σ０＝σ０（ｔ，σｓ，Ｓ）。

Creep Internal Stress of the Unidirection Carbon-Carbon Composite

The creep internal stress ac of the unidirection C/C composite which consists of T300 carbon fiber (based on PAN precursor) as the reinforcement and pyrolytic carbon as the matrix is determinated by means of the stress drop method. Results and analysises show that o of the unidirection C/C composite isn't a constant but a function of the temperature T, start stress and structure factor S, i. e. o=o(T, o, S). For same type of meaterial with a same S and under constant start stress s, o=0. 086T+290. 6; and at a same temperature, o increases with increment of o. A viscoelasticity model based on the microstructure model of T300 carbon fiber/pyrolytic carbon unidirection composite is suggested and used for analyzing the physical nature of its creep internal stress. It is considered that o implicates that the interface takes a effect of impeding the creep and o is sensitive to the interface.