Effect of UV/ozone-functionalized graphene on interfacial adhesion and load transfer in co-cured GFRP joints

Adhesive bonding is widely used to assemble composite parts in modern manufacturing industries to reduce the drawbacks associated with mechanical fastening. The main aim of the current research is to improve the shear strength and fundamental natural frequency of co-cured GFRP composite joint by incorporating graphene nanoparticles (GNPs) into the adhesive. The UV/O3 functionalization was carried out with GNPs to improve the interfacial bonding. The experimental results revealed that the incorporation of 0.5 wt.% TGNPs in epoxy adhesive enhance the tensile strength by 49% and shear strength by 47% compared to plain epoxy. Fractographic analysis confirms a transition from adhesive to cohesive-dominated failure, indicating enhanced interfacial bonding and crack resistance. Furthermore, vibration analysis demonstrates an increase in natural frequency due to improved interfacial stiffness and efficient stress transfer across the adhesive layer. Overall, UV/O3 functionalization of GNPs enhanced the interfacial bonding behavior of the adhesive and joint performance. The present findings provide a viable pathway for advanced composite bonding applications that demand enhanced mechanical reliability. The infographic described that UV/O3-functionalized graphene nanoparticles were incorporated into epoxy adhesive used in co-cured GFRP single-lap joints. Also, the Enhanced nanoparticle dispersion and interfacial bonding improved load transfer, promoted crack deflection and bridging mechanisms, and significantly increased the tensile, shear, and dynamic performance of the bonded composite joints.