冻融环境下CFRP板-钢界面黏结性能试验研究

Experimental study on bond behavior of CFRP plate-steel interface in freeze-thaw environment

为了研究冻融环境对碳纤维增强复材CFRP板与钢界面黏结性能的影响,进行了12个CFRP板-钢双剪节点的测试,分析了失效模式、极限荷载、CFRP板应变、界面剪应力和黏结-滑移关系.试验结果表明:冻融循环次数对界面失效模式基本没有影响,所有试件均为胶层失效.随着冻融循环次数的增加,结构胶力学性能和界面极限荷载均逐渐下降,300次冻融循环后结构胶弹性模量和抗拉强度分别下降9.3%和10.3%,界面极限荷载下降14.5%;冻融环境对CFRP板应变分布、界面剪应力分布和黏结滑移关系的曲线形状没有影响,黏结滑移关系曲线近似为双线性,但冻融循环作用会导致CFRP板最大应变、最大界面剪应力及其对应滑移和最大滑移下降.

To investigate the effect of the freeze-thaw environment on the bond behavior between the carbon fiber reinforced polymer(CFRP)plate and steel,12 CFRP plate-steel double-shear joints were tested.The failure mode,the ultimate load,the CFRP plate strain,the interfacial shear stress and the bond-slip relationship were analyzed.The experimental results show that the number of the freeze-thaw cycles has no effect on the failure mode and all specimens exhibit cohesive failure.However,with the increase in the number of freeze-thaw cycles,the mechanical properties of the adhesive and the ultimate load of the interface decrease.After 300 freeze-thaw cycles,the elastic modulus and the tension strength of the adhesive decrease by 9.3%and 10.3%while the ultimate load decreases by 14.5%.The freeze-thaw environment has no effect on the curve shapes of the CFRP strain distribution,the interfacial shear stress distribution and the bond-slip relationship.The bond-slip relationship curve is approximately bilinear.The freeze-thaw environment can reduce the maximum strain on CFRP plate,the maximum interfacial shear stress and the corresponding slip,and the maximum slip.