A novel 3D fibre-reinforcement architecture for high performance natural fibre reinforced composite adhesively bonded joints

In this paper, the effect of a novel fibre reinforcement architecture in the adhesively bonded joint efficiency of natural fibre reinforced composites (NFRC) was investigated. Two different reinforcement techniques were used: intralaminar reinforcement (2D) and orthogonal-through-the-thickness reinforcement (3D). The aim of the novel architecture is to enhance the transverse properties of the adherend (transverse strength and fracture toughness) in order to delay or avoid delamination failures. A jute bidirectional fabric was used as a base primary reinforcement phase and curauá, sisal, ramie, hemp and glass fibres were used as secondary reinforcement phases for the 2D and 3D fibre reinforcement architectures. Single lap joints (SLJs) bonded with an epoxy adhesive used in the automotive industry were fabricated with these adherends and the efficiency of the joints was investigated by comparing them to glass (GFRP) and carbon (CFRP) pure synthetic fibre reinforced composite joints. It was found that the novel architecture was successful in reaching the failure load of the synthetic composite joints for SISAL 3D, CURAUÁ 2D and CURAUÁ 3D SLJs. Therefore, NFRC bonded joints can be a viable replacement for synthetic fibre composite joints at no load-bearing loss.