通过拉丝法测定了5228A环氧树脂在不同温度下的凝胶时间,选择了特定的预固化温度;在预固化温度下制备了不同预固化度的碳纤维增强环氧树脂基复合材料,采用DMA测试了预固化复合材料层板的玻璃化转变温度;采用自制粘接模具制备了复合材料自粘结接头,测试了复合材料接头的搭接剪切性能;采用光学显微镜观测了自粘结搭接结构和剪切断口形貌,分析了搭接结构对剪切强度的影响。结果表明:复合材料层板的预固化度〈αgel时,接头的搭接剪切强度变化不大,当预固化度〉αgel时,接头的搭接剪切强度降低幅度较大;剪切性能受搭接结构的完整性影响较大。
The gel times of epoxy resin 5228A at different temperature were tested by silk drawing and the specific pre-curing temperature was determinated.Then pre-curing carbon fiber reinforced epoxy composites with different curing degrees were prepared at the selected temperature and the glass transition temperature(Tg)of the composites was tested by dynamic mechanical thermal analysis(DMA).The self-adhesion single-lap joints of the composites were prepared using self-made moulds and the shear properties of the joints were tested. The structure and fracture surface of self - adhesion single lap joints were observed by optical microscope. The influence of single lap joint structure on the shear strength were analized. The results showed that the lap shear strength of epoxy com- posites with pre - curing degree 〈 αgel changed little and declined sagnificantly when pre - curing degree 〉 αgel . The lap shear properties were depended on the integrality of single lap joints.