Bond-slip behavior of fiber reinforced polymer strips-steel interface

Fiber reinforced polymer (FRP) composites have been widely and successfully applied for externally bonded strengthening of steel structures. The bond between FRP and steel substrate plays a key role on the strengthening effectiveness of FRPs. The bond-slip relationship is essential to understand the mechanisms involved in the bond failure process. This paper experimentally studied the bond behavior of carbon fiber reinforced FRPs (CFRP)-to-steel joints through a single-shear lap testing method. The load-displacement relationship and bond-slip relationship were firstly presented. In addition, a new bond-slip model was developed based on observed experimental behavior of strengthened components. According to the developed bond-slip model, a computed result of the load-displacement relationship was obtained using numerical analysis method by ANSYS software. Comparison between computed and experimental result of the load-displacement relationship showed a good accordance, indicating the reliability of the developed bond-slip model. Finally, comparison of computed results obtained from the developed model and the existing models demonstrated that the proposed model was more accurate than the existing models.