Determination of Water Diffusion Coefficients and Dynamics in Adhesive/Carbon Fiber Reinforced Epoxy Resin Composite Joints

To determinate the water diffusion coefficients and dynamics in adhesive/carben fiber reinforced epoxy resin composite joints, energy dispersive X-ray spectroscopy analysis（EDX） is used to establish the content change of oxy- gen in the adhesive in adhesive/carbon fther reinforced epoxy resin composite joints. As water is made up of oxygen and hydrogen, the water diffusion coefficients and dynamics in adhesive/carben fiber reinforced epoxy resin composite joints can be obtained from the change in the content of oxygen in the adhesive during humidity aging, via EDX analy-sis. The authors have calculated the water diffusion coefficients and dynamics in the adhesive/carbon fiber reinforced epoxy resin composite joints with the aid of beth energy dispersive X-ray spectroscopy and elemental analysis. The de- termined results with EDX analysis are almost the same as those determined with elemental analysis and the results al- so show that the durability of the adhesive/carbon fther reinforced epoxy resin composite joints subjected to silane cou- pling agent treatment is better than those subjected to sand paper burnishing treatment and chemical oxidation treat- ment.

基于激光热弹效应的碳纤维增强树脂复合材料缺陷检测机理研究

碳纤维增强树脂基复合材料(carbon fiber reinforced resin polymer, CFRP)在周期载荷作用下产生的基体裂纹、纤维断裂等微损伤的累积会严重影响CFRP的力学性能,微损伤尺寸较小且位置分散,传统的无损检测方法难以准确识别。激光超声检测技术具有非接触、检测速度快、测量范围广等优点,特别是结合激光的远距离激励和大角度入射的优势,在大尺寸、曲面形式结构材料的损伤检测方面有巨大的潜力。本文基于激光热弹效应,在分析激光作用到CFRP后的温度、应力和位移场分布的基础上,对CFRP内部超声波的产生过程和传播特性进行了系统研究。并通过对CFRP中不同处存在缺陷时的超声波回波信号的分析比较,得到缺陷位置与回波信号特性之间的对应关系,从而实现从回波信号特征反演出CFRP中缺陷位置的关键信息。