Structural Performance of Corner Joint Reinforced with FRP under Diagonal Tension Loading

In this study, structural performance of corner joint reinforced by fiber reinforced polymers (FRP) at the area of maximum tension stress was investigated under diagonal tension loading. Therefore 1 to 3 layers of unidirectional woven of Glass, Carbon and Kevlar were used and hand lay-up was done by vinyl ester and epoxy resins. Results of load-displacement curve at yield point exhibited capability of the reinforcing layers in preventing joint opening to some extent under load. However, failure was observed at the joint due to picking fibers from wood surface or members fracture near the interface when loading increased. Since the reinforced zones of the joints by FRP show the maximum shear stress, consequently the separation of fibers from wood surfaces increased at these locations. The adhesion of FRP layers to joint surface was not appropriate due to difficult process of layering at right angle of joints followed by probable formation of air bubbles. The results of assessing FRPs reinforcing behaviour indicated that application of vinyl ester in comparison with epoxy as matrix exhibited better performance. In addition, glass and carbon fibers showed better performance than Kevlar fibers as reinforcing agents.