Influence of 3D printed adherend design on structural performance and vibrational behaviour of adhesively bonded joints

Adhesively bonded joints are typically prone to failure at overlapping ends due to high shear and peel stresses. Several methods have been developed to reduce the shear stress and improve the strength of adhesive joints. One potential approach is to modify the overlapping area into a joggle and wavy form configuration, which reduces the stress concentration and enhances the performance of adhesive joints. The present study investigated the impact of joggle and wavy-shaped overlapping areas on the load-carrying behaviour of additive-manufactured lap joints. Adhesive joints with joggle and wavy design configurations were fabricated with Acrylonitrile butadiene styrene through a fused deposition modelling approach. Shear analysis revealed that the joggle and wavy-shaped design significantly improved the structural integrity of the joints, with load-carrying capacities enhanced by 65.91% and 55.45%, respectively, compared to single-lap joints. Failure surface examination showed that the single lap joint failed in adhesive mode, while the joggle and wavy joint failed in cohesive mode. Experimental free vibrational analysis revealed that the joggle and wavy-shaped 3D printed adhesive joints had a higher natural frequency than single lap joints. The proposed joint design configurations and findings can be used to fabricate 3D-printed adhesive joints with better structural integrity.