Effects of residual stress on the stability of multi-welded integral stiffened panels

In order to clarify the influence of residual stress on the stability of 2024-T3 friction stir welded(FSWed) integral stiffened panels with multi-welds, the ANSYS software was used to establish the finite element models of two typical multi-FSWed stiffened panels. The residual stresses of two typical multi-welded stiffened panels (Panel A and Panel B) were calculated respectively using the thermal-mechanical coupling method. And the buckling and post-buckling responses of the stiffened plates were analyzed. It is shown that the residual stress distribution of stiffened panel was affected by the welding sequence. The maximum residual stress of Panel A mainly appears on the right side of the stringer, and that of Panel B appears on the stringer that is welded later. The residual stress has a great influence on the stability of the welded stiffened panels. When the residual stress profiles are taken into consideration, the critical buckling loads of welded Panel A and Panel B will decrease 14.2% and 12.4% respectively.