Experimental Evaluation of the Effect of External Restraint on Buckling behavior of Thin Welded Shells

Welding induces residual stresses in structures which may cause buckling distortion, if they exceed the critical buckling stress of the structure. This paper presents a predictive distortion analysis approach for a welded structure. In addition, the effect of external constraint on buckling behavior is studied, as well. A 3-D thermo-mechanical welding process simulation is performed to determine the residual stresses and deformation. Moreover, the critical buckling stress along with the buckling mode is computed through 3-D eigenvalue analysis. Also, the model is validated against the experimental work. The present results clearly demostrate that the proposed 3D welding analysis can predict not only the time, but also the shape of buckling during welding. Finally, this study also reveals that external restraint effect on buckling mode as well as a suitable combination of thickness and external restraint can eliminate buckling.