Low-velocity impact and bending response of graphene nanoparticle-reinforced adhesively bonded double strap joints

The low-velocity impact and bending performance of adhesive joints are critically important for their reliable use in multiple industrial applications. Enhancements of adhesive joints’ mechanical properties are significantly valuable for the long-term safe use and overall life of structural components. This study investigated the low-velocity impact and bending properties of double strap joints (DSJs) reinforced with graphene nanoplatelets (GNPs). In this context, GNP-reinforced adhesives with 1%, 2%, and 3% reinforcement by weight were prepared, and the dispersion quality of graphene was examined using scanning electron microscopy. Subsequently, graphene-modified DSJs were manufactured and mechanical tests were carried out. Low-velocity impact tests were performed at 5 J and 10 J energies in a single impact configuration. Tests of the nonperforated specimens showed that the contact force increased with graphene reinforcement. The absorbed energy and the contact time of the specimens with the impactor tip decreased with nano reinforcement by 5% and 4%, respectively. Additionally, a significant decrease in the displacement was observed with 2% and 3% graphene reinforcements. Significant improvements of up to 58% were observed in the flexural strength of the joints with graphene reinforcement.