Experimental and analytical studies of failure characteristics of FRP connections

Abstract

This study presents the failure characteristics of FRP lap joints in tension using experimental and analytical techniques. The lap joint is made from coupons extruded from laminated plates and pultruded beams. FRP plates are fabricated from different fabrics and stacking sequence of fibers. Extensive study is performed on changing the end distance-to-bolt diameter ratio, bolt diameter-to-thickness ratio, and stacking sequence of the laminates. Coupons are connected through bolts and/or adhesive. It is observed that the failure of the bonded connection is very brittle while those connected by bolt and adhesive have ductile failure. Adhesive joints failed by failure of external layers, while bolted joints have bearing failure of coupons as well as shear failure of coupons and bolt. It is noted that the strength of the joint increases with increase in the overlapping length, while it decreases with increase in bolt diameter. The quasi-isotropic, i.e., (0/90/±45)s have higher failure strength than cross-ply and angle-ply laminates.