动态拉伸荷载下温度对CFRP/钢板单搭接剪切接头力学性能的影响  

Temperature effect on the mechanical properties of CFRP / Steel single-lap shear joints under dynamic tensile loading

作　　者：朱德举[1] 姚明侠 张怀安[1] 火兴斐 

机构地区：[1]湖南大学,湖南长沙410082

出　　处：《土木工程学报》2016年第8期28-35,共8页China Civil Engineering Journal

摘　　要：采用真空辅助树脂灌注成型工艺（VARI）制作了CFRP，将CFRP和钢板利用环氧树脂胶黏结起来，制备了CFRP／钢板单搭接剪切接头。利用MTS液压伺服高速机测试了试件在恒定动态加载速率（0．625m／s）和不同温度（-25℃，0℃，50℃，10℃）作用下的力学性能。试验结果表明，接头的拉伸剪切性能（黏结强度、界面断裂能、剪切刚度）与温度具有相关性。在一定的范围（-25—50℃）内，随着温度的升高，接头的黏结强度和界面断裂能随之增大，但当温度超过环氧树脂胶的玻璃转化温度时，接头的黏结强度和界面断裂能急剧下降。不同温度下的破坏模式有所不同：在低温（-25℃和O℃）时，接头的破坏模式表现为钢板与胶层之间的界面破坏；在50℃时，接头的破坏模式表现为部分胶体分别残留在CFRP和钢板的混合破坏；当温度达到100℃时，接头发生胶层与CFRP之间的界面破坏。最后，通过数字图像相关技术（DIC）对不同温度下试件的搭接区域的FRP应变场进行了分析，结果表明搭接区域端部的应变大于内部的，且试件的破坏也从端部开始发生。CFRP was made by vacuum assisted resin infusion （VARI） and CFRP/Steel single-lap shear joints were manufactured by bonding steel plate and CFRP together with epoxy resin. Specimens were tested under four temperatures （ -25, O, 50, 100% ） with the same loading rate （0.625 m/s） by means of a servo-hydraulic high rate testing system. The experimental results show that the mechanical properties of joints are sensitive to temperature. In a certain range, the bond strength and interfacial fracture energy of joints increase between - 25℃ and 50℃. When the temperature exceeds the glass transition temperature of the adhesive, bond strength and interfacial fracture energy decrease significantly. The failure modes of specimens are different at different temperatures. At the low temperatures （ -25℃ and O℃ ）, the failure mode of joints is adhesive/steel interface failure. At 50℃, the failure mode changes to mixed failure. When the temperature reaches 100℃, the failure mode is adhesive/CFRP interface failure. Moreover, the FRP strain field distribution in the overlapping area at different temperatures was analyzed by digital image correlation （DIC） technique. The results show that strain of FRP at the edge is lager than that at the center, and final failure initiates at the edge of the specimen.

关 键 词：单搭接接头 温度 加载速率 黏结强度 破坏模式 

分 类 号：TU392.4[建筑科学—结构工程]