Enhancement of Mechanical Performance in Epoxy Adhesive Joints through Graphene Nano Oxide Particle (GNOP) Modification

This study investigates the effect of graphene nano oxide particle (GNOP) reinforcement on the bending performance of DP460 epoxy adhesive joints used for St37 steel repair. Patches were prepared at 90° and 120° wrap angles with 40, 50, and 60 mm lengths, and the adhesive was modified with 0.1, 0.2, and 0.3 wt.% GNOP. Results showed that increasing patch size and wrap angle improved bending strength up to 50%, while the 0.2 wt.% GNOP addition provided an optimal 30–35% enhancement in load capacity compared with unreinforced joints. Fracture analysis indicated a transition from cohesive to adhesive failure, confirming improved interfacial bonding and toughness due to uniform GNOP dispersion.