Finite Element Analysis of Bonding Performance of Prestressed CFRP-Steel Interface

In order to investigate the bonding performance of the interface between prestressed CFRP fabric and steel, a prestressed CFRP-steel single-shear specimen was modeled using ABAQUS. The nonlinear bond-slip characteristics of the interface were simulated by utilizing the cohesion unit. The impact of various factors such as the degree of pre-stressing of CFRP fabric, number of layers, pasting width, paste length, and thickness of the adhesive layer on the interface bond performance of the prestressed CFRP-steel single-shear specimens was analyzed. The simulation results indicate that the primary cause of failure for the prestressed CFRP-steel interface is cohesive damage to the adhesive layer. The presence of prestressing allows the adhesive layer of the specimen to offset part of the external force, improving the interfacial bonding performance. The load-end displacement curves of the prestressed CFRP-steel specimens display a two-phase development law. The ultimate load of the specimen is increased by the degree of prestressing of the CFRP fabric, the pasting width, and the adhesive layer thickness. As the adhesive layer thickness, adhesive width, and CFRP fabric prestressing increase, the ultimate load and ductility of the specimens also increase. However, adding more layers of CFRP fabric will only lead to a higher ultimate load and reduced ductility for the specimens. An increase in adhesive layer thickness in the 0.3~0.7 mm range results in a nonlinear improvement in interfacial stiffness. On the other hand, a linear improvement in interfacial stiffness is observed by increasing the number of layers of CFRP cloth prestressing within the range of 1~3, resulting in a 24% increase for each additional layer.