Influence of welding sequence and external restraint on buckling distortion in thin-plate arc-welded joints

Buckling distortion as a troublesome engineering issue is easily generated in thin-plate arc-welded components (generally less than 4 mm in thickness). This study aims to clarify the impact of welding sequence and external restraint on out-of-plane deformation in thin plates for finding out an effective and practical strategy for the prevention of welding-induced buckling distortion. The experimental method was utilized for investigation here. The experimental results reveal that the external restraint cannot prevent buckling distortion in the thin-walled weldments, while it can significantly mitigate the amount of transverse (about 4 mm here) but not longitudinal bending. The welding sequence method can prevent buckling distortion, but it cannot eliminate the transverse bending induced by the non-uniform temperature field in the thin-plate thickness direction. In the present work, the transverse bending in the symmetrical welding is the lowest (about 4 mm), while that in the back-step welding is the largest (around 7 mm). Furthermore, symmetrical welding and continuous welding introduce the lowest (about 1 mm) and highest (about 4 mm) longitudinal bending, respectively. Both external restraint and welding sequence could affect the buckling distortion mode. For the thin-plate arc-welded components, symmetrical welding combined with external restraint is a very effective strategy for the prevention of buckling distortion.