Enhancing shear and flexural strength of single lap composite joints with a graphene nanoparticle‐reinforced adhesive through a co‐curing technique

Abstract

AbstractAdhesive‐bonded joints in glass fiber‐reinforced polymer (GFRP) composite structures give numerous benefits, such as greater flexibility, good specific strength, improved fatigue resistance, and the ability to reduce stress concentration. Consequently, adhesive‐bonded joints are considered more influential if compared to fasteners. This research investigates the effects of incorporating graphene nanoparticles (GNPs) into the adhesive layer on several aspects of adhesively bonded co‐cure (CC) single‐lap GFRP composite joints. These aspects include shear strength, flexural strength, failure mechanisms, and fractography studies. The study examined six distinct weight percentages of GNP, specifically 0.25, 0.50, 0.75, 1.0, 1.25, and 1.5 wt.%, which are considered to enhance the interfacial strength of adhesive joints. Based on the research, 0.75 wt.% of GNP single‐lap joint (SLJ) shear strength improved by 69.40% when compared to the plain matrix SLJ. This suggests excellent load transmission between adherends. In addition, the flexural strength increased by 46.57% in the specimens containing 1.25 wt.% GNP when compared to the plain matrix used to bond in SLJ. After testing, fractured specimen microscopic images were used to examine failure mechanisms. According to fractography studies, adding GNPs to the adhesive causes surfaces to become rougher, which improves the adhesion between the adhesive and the adherends.Highlights Six distinct wt.% of GNPs were used to prepare the matrix by sonication. Single‐lap GFRP composite joints were fabricated through a CC technique. SLJ's maximum shear strength was found at 0.75 wt% of GNP. SLJ's maximum flexural strength was found at 1.25 wt% of GNP. Failure analysis was conducted using microscopes and FESEM images.