Effect of Fillet Angle on Stress in Weld-Bonded Aluminum Joints

The influence of fillets with varied angle on the stress distributed in weld-bonded aluminum alloy single lap joint was investigated using elasto-plastic finite element method (FEM). The results from the numerical calculation showed that the peak stress along the mid-bondline at the point near the free ends of the adherend is increased evidently as the fillet angle increased but there is no significant relation between the peak stress in the nugget and the fillet angle except shear stress Sxy which is increased with the fillet angle. The stress concentration is reduced in both adhesive layer and the adherend near the interface at the points near the ends of the lap zone of single lap weld-bonded aluminum joint as the fillet angle decreased. Thus the stress distribution in overlap zone was improved that may increase the load-bearing capacity of the joints. The fillet angle of 300 or 450 is recommended in practical use.