Performance enhancement of adhesive joints of additive manufactured parts by using different types of fibre reinforcements

Abstract

The main objective of this study was to investigate experimentally the mechanical performance of adhesive joints made of additive manufactured (AM) polymeric parts reinforced with different types of fibres. PLA (PolyLactic Acid) and ABS (acrylonitrile butadiene styrene) AM adherends were fabricated by fused deposition modelling (FDM). Further, natural (jute and curauá) and synthetic (glass) fibre reinforcement fabrics were laminated on the outer sides of the AM parts using an epoxy resin via compression moulding. The type of reinforcement (natural or synthetic) and the effect of the number of the layers (1 and 2 layers) on the performance of the bonded joints was studied by testing single lap joints (SLJs) bonded with an epoxy structural adhesive. It was found that the mechanical performance of adhesively bonded SLJs is improved by using different types of fibre reinforcements to the 3D printed core adherends. The failure load varied as a function of fibre type and number of layers used as reinforcement, as well as the material used for the core of the adherends. The ABS SLJs presented lower strength compared to PLA SLJs, mainly due to the ABS adherend inferior mechanical properties. In addition, the PLA core specimens presented a better interface adhesion with the epoxy resin used in this study to laminate the reinforcements, when compared to the ABS core reinforced specimens. The best results in terms of improvement in failure load were obtained for the curauá fibre reinforced PLA 3D printed SLJ specimens (the average joint strength was more than 1.5 times higher than the neat-PLA SLJ specimens).