Effect of spew fillet on adhesively bonded single lap joints with CFRP and aluminum-alloy immersed in distilled water

Abstract The aim of this study was to investigate the effect of a spew fillet on adhesively bonded single lap joints (SLJs) with carbon fiber-reinforced plastic (CFRP) and an aluminum alloy immersed in distilled water. After the SLJs with and without the spew fillet were immersed in distilled water for a specified aging time, the strengths of the SLJs were measured via quasi-static axial tensile experiments, and the strain distribution at the side interface of the adhesive layer in the joints was obtained via digital image correlation (DIC) technology. The tensile test results showed that the strength of the SLJs can be significantly improved by introducing the spew fillet, and the strength of the SLJs decreased as the aging time increased both with and without the fillet. However, compared with the SLJs without the fillet, the strength of the SLJs with the fillet decreased further. The DIC results showed that the main reason for the influence of the fillet on the SLJs was that the fillet enhanced the peel strength and shear strength of the adhesive layer in the overlap area.