Adhesive joints are widely used in industries such as aerospace and shipbuilding due to their unique mechanical and structural advantages. This study investigates the mechanical performance enhancement of single-lap adhesive joints (SLAJs) through the incorporation of graphene oxide (GO) nanoparticles into a two-part epoxy adhesive (AD-311). Samples containing 0.1%, 0.3%, and 0.5% GO by weight were prepared, and their tensile and compressive behaviors were evaluated according to ASTM standards. Scanning electron microscopy (SEM) revealed improved fracture surface roughness and energy absorption, particularly at 0.3 wt% GO, which exhibited a 35.65% increase in joint failure load. Finite element analysis (FEA), using the Drucker-Prager plasticity model, demonstrated excellent agreement with experimental results, validating the predictive capability of the simulation. The influence of adhesive thickness and bond length was also numerically assessed using FEA, showing that thinner adhesive layers and longer joints enhance load-bearing capacity. Stress and strain distributions further elucidated the positive role of GO in increasing shear and equivalent stress resistance while reducing plastic strain. These findings confirm that optimizing GO concentration significantly improves joint strength and durability, offering promising implications for structural adhesive applications in engineering.
