Experimental Study On Bond Behavior Of CFRP-to-steel Interface

At present,carbon fiber reinforced polymer(CFRP)has been gradually applied to the reinforcement of steel structures.The peeling failure of CFRP and steel interface is the most important failure mode of steel structure reinforced by CFRP.Therefore,the interface of these two materials become the focus and hotspot of researchers.In this paper,the combination of experimental research and theoretical analysis is used to study the bonding mechanism,shear stress distribution and the microstructure of CFRP and steel interface.The main work contents include:In this paper,the interface single shear test of the specimens was completed.The influence of CFRP layers,bonding width,adhesive thickness and the treatment form of steel plate on the interface bonding performance was analyzed.And three failure modes were obtained.The results show that the damage of the specimen occurs mainly at the adhesive-steel interface;the interface ultimate load increases linearly with the width of CFRP,and increases nonlinearly with the increase of the CFRP layers.The peeling load of the blasted specimen is reached the maximum value.Secondly,based on the value of the surface roughness of the steel plate and the scanning electron microscope of the bonding interface,the different surface roughness is quantified with relevant parameters,and the microscopic bonding condition of the CFRP and steel plate interface is presented.The microscopic research method of the interface is proposed.The results show that sand blasting can homogenize the surface of the steel plate,enhance the wettability of the adhesive on the surface of steel plate,and improved the bond strength of the interface.Finally,the bond-slip constitutive model and bond strength model affected by multiple variables are established,which realized the quantitative analysis of the bond performance between CFRP and steel plate.The results show that the theoretical prediction model agrees well with the experimental results.