Effect of mechanical insert on the behaviour of pultruded fibre reinforced polymer (FRP) bolted joint

The performance of joints has been regarded as the main factor that limits the growth of pultruded fibre reinforced polymer in civil engineering applications. This paper investigates the effect of mechanical insert on the joint strength and failure mechanism of pultruded glass FRP (GFRP). Three (3) types of specimens were used namely joint without mechanical insert, joint with mechanical insert but without adhesive and joint with mechanical insert and adhesive. This corresponds to the specimens N, I and G, respectively. A total of fifteen specimens were tested up to failure in ambient temperature. The experimental results showed that the presence of mechanical insert has improved the joint strength by 24% and the joint stiffness by 26% of pultruded GFRP bolted joint. Meanwhile, adhesively bonded mechanical insert used in specimen G is capable to contribute almost 92% improvement of joint strength. Most of the test specimens failed in shear-out mode. Specimens I and G exhibited brittle-type failures after the maximum load. This preliminary study shows good performance of mechanical insert in improving the bolted joint connection of square hollow section (SHS) pultruded GFRP profile.