基于双剪实验的CFRP-钢板界面粘结性能研究

Study on bonding performance of CFRP-steel plate interface based on double shear test

碳纤维增强复合材料CFRP(carbon fiber reinforced polymer)因其优越的力学性能,在结构加固领域得到了广泛的应用。CFRP对钢结构的加固效果取决于CFRP-钢界面的粘结性能。基于双剪实验对CFRP-Q345B钢板和CFRP-X100钢板的界面粘结性能进行了研究,利用数字图像相关DIC(digital image correlation)应变测量系统和应变仪同时测量CFRP的表面应变,研究了CFRP-钢界面的破坏特征和力学行为,分析了胶层厚度与钢板材质对界面剪切性能的影响。结果表明:胶层厚度为0.1 mm和0.5 mm时,界面的破坏模式分别为钢板-胶层界面破坏和胶层内聚破坏;极限承载力受钢板材质的影响,粘结剂与Q345B钢板的粘结力要大于其与X100钢板的粘结力;DIC测量系统得到的界面剪应力分布比应变片测量结果能够更加全面、直观地反映粘结界面的力学行为。

CFRP is widely used in the field of structural reinforcement due to its superior mechanical properties.The reinforcing effect on steel structures is affected mainly by the bonding behavior of interface between CFRP and steel.In this paper,the specimens of CFRP-Q345B steel plates and CFRP-X100 steel plates under double shear test are used to investigate the bonding behavior of interface.And the surface strain of CFRP is simultaneously measured by DIC measuring system and strain gauges.The failure characteristics and mechanical behavior of CFRP-steel interface are studied,and the effects of adhesive layer’s thickness and steel plate material on interfacial shear performance are discussed.The test results show that:when the thickness of adhesive layer is 0.1 mm and 0.5 mm,the failure modes of interface are steel plate-adhesive layer interface failure and cohesive failure of adhesive layer respectively;the ultimate bearing capacity is affected by the steel material,and the bonding force between the adhesive and Q345B steel plate is greater than that between the adhesive and X100 steel plate;the interfacial shear stress distribution measured by DIC measuring system can reflect the mechanical behavior of bonding interface more comprehensively and intuitively.