Multi-scale reinforcement effects on co-cure GFRP joints: Synergistic influence of chopped glass strand mat and graphene nano-particles on joint strength and failure mechanism

Abstract

The present study investigates the effect of multi-scale reinforcement such as graphene nano-particles (GNP) and chopped glass strand mat (CGSM) on flexural and shear strength of the glass fibre reinforced composite single-lap joints (SLJ) using a co-cure manufacturing technique. Experimental results depicted that SLJ with multi-scale reinforcement enhances the strength of joint drastically. SLJ prepared by 0.5 wt.% GNP with CGSM reinforcement enhanced the shear strength by 67.2% compared to reinforcement-free SLJ due to the formation of a rough surface over the surface bond area. Thus, it improves the interfacial bonding between fibre and matrix. On the other hand, 0.75 wt.% GNP with CGSM reinforcement enhanced the flexural strength by 47.2%. This study demonstrated that selecting the appropriate proportion of GNP with CGSM can improve the shear and flexural behaviour of composite joint. Also, fractography findings reported that higher concentrations of GNP with CGSM reinforcement leads to agglomeration, reducing the joint strength.