Graphene nanoparticle effect on flexural and shear behaviors of adhesively bonded single lap joints of GFRP composites

Adhesive bonded joints of fiber-reinforced polymer structural components provide countless benefits; these include great strength and large hardness-to-weight ratios, good fatigue and corrosion resistance, and high energy absorption capability, all of which make them more influential in comparison with other types of fasteners. In this study, the effect of various contents of graphene nanoparticle (GNP) in the epoxy adhesive on the shear and flexural behaviors of glass fiber-reinforced polymer plates (GFRP) bonded joints are investigated. Based on the weight content of epoxy graphene, nanoparticles were added by 0.1, 0.2, 0.3, 0.4, and 0.5 wt.%. GFRP were used as adherents. Failure mechanisms were analyzed by taking photos over the front and rear sides of the samples after tests. The obtained results showed that 0.3 wt.% graphene nanoparticle addition exhibiting the better load transferring between adherents had 145% improvements in shear strength. Furthermore, the samples containing 0.2 wt.% GNP resulted in an increase in flexural strength by 100%.