Influence of bolt preload of anchors on bond-slip behavior of fiber fabric-steel interface

Bond-slip behavior is a common failure mode in steel structures reinforced with fiber fabric. Premature debonding of the fiber fabric significantly impacts the effectiveness of steel structure reinforcement. In this study, a gripping anchor is proposed to enhance the reliability of the interface between fiber fabric and steel plates. Experimental investigations were conducted to analyze the influence of anchor bolt preload on the double shear joint between fiber fabric and steel plates. 41 specimens were prepared and tested to explore the effects of parameters such as bolt preload, anchor position, number and type of fiber fabric layers, and bond length on load-bearing capacity. Comparative analyses were conducted on failure modes, ultimate loads, and stress-strain distributions of the specimens. Experimental results indicate that the position of the anchor has a minimal impact on the ultimate bearing capacity of the specimen. However, anchors positioned closer to the joint end exhibit lower ductility upon failure. A novel predictive model was developed to characterize the bond-slip behavior of preload applied to carbon fiber fabric and steel plates. The theoretical model of the ultimate bearing capacity in the yield stage fits well with the experimental results of specimens with three layers of carbon fiber fabric, with a difference range of 0.34 % to 14.97 % compared to actual results. This indicates that the model has high accuracy in predicting stress-strain and bearing capacity.