The effect of the spew fillet on an adhesively bonded single-lap joint subjected to bending moment

The mechanical behaviors of an adhesively bonded single lap joint with a spew fillet under bending moment, where the widths of the upper-adherend and lower-adherend are not the same, were studied experimentally and numerically. Using AA2024-T3 aluminum alloy as adherend and DP460 as paste adhesive, four different types of single-lap joint samples (without spew fillet, with spew fillet at joint edges, with spew fillet at joint ends and with spew fillet at all edges) were produced for experimental studies. Stress analyses in the single-lap joint were performed with a three dimensional non-linear finite element method by considering the geometrical non-linearity and non-linear material behaviors of both adhesives (DP460) and adherend (AA2024-T3). The single lap joint with the spew fillet with different widths had a significant effect on the stress distribution. Additionally, the spew fillet increased the load carrying capacity of the joint and decreased the stress concentration of the joint.