Effect of hybridization and composite architecture symmetry in the bonded joint performance of jute/carbon fibre-reinforced composites

This study investigates the effect of hybridization and composite architecture symmetry in the bonded joint performance of jute/carbon fibre-reinforced composites. Jute and carbon fibre bidirectional fabrics were used as reinforcement fibres for interlaminar hybrid epoxy composite adherends. The effect of the number of carbon fibre layers (1 and 2) as well as layup symmetry on the mechanical performance of the bonded joints was studied by testing single lap joints (SLJs) bonded with two adhesive types (a structural ductile bi-component epoxy adhesive and a brittle one). It was found that the hybridization of jute fibre reinforced composites with carbon fibres significantly improved the bonded joint performance for all tested specimens, when compared to the neat jute fibre reinforced composites (maximum of approx. 69 %). However, when compared to the neat carbon fibre (CFRP) adherend joints, the hybrid jute/carbon adherend joint configurations studied here achieved up to approximately 94 % (ductile adhesive system) and 97 % (brittle adhesive system) of maximum joint load efficiency of the CFRP synthetic joint. The effect of composite architecture symmetry was more pronounced for the brittle adhesive joints, whereas the failure loads of the ductile adhesive joints exhibited a plateau-like trend (ductile adhesives accommodate better the bending moments during SLJ loading, while brittle adhesives are more sensitive to adherend stiffness). A jute/carbon fibre hybrid composite bonded structure presents a potentially cost-effective and efficient alternative for reducing the structural carbon footprint, without a significant compromise in mechanical properties.