Hybrid laser-arc welding-induced distortions analysis of large-scale thin-walled cruise ship structures

In recent years there has been increasing use of thin-walled structures with a plate thickness of 6mm-10mm in the construction of cruise ships. As one of the important processes of cruise ship construction, hybrid laser-arc welding, combing the advantages of laser welding and arc welding, is increasingly applied in thin-walled cruise ships with the objective of reducing panel deformation. However, due to the weak stiffness of the thin-walled structure with a continuous weld length of 4m-16m, complex welding deformation, e.g., buckling deformation will be prone to occur. This paper analyzed the deformation behavior of large-scale thin-walled cruise ship structures with the change of weld length, structural width, and plate thickness in hybrid laser-arc welding process. The buckling mode induced by the welding deformation is predicted based on the combination method of thermal elastic-plastic and inherent strain, as well as experimental verification. Comparing the deformation behavior of large thin-walled cruise ship structures, when the continuous weld length exceeds 7.5m during butt welding, the welding deformation mode transitions from bending deformation to buckling deformation. Comparing the buckling behavior of structures with different thicknesses at a length of 15m, a slight buckling occurs with a plate thickness of 10mm, but reducing the plate thickness to 6mm leads to severe buckling deformation with up to 7 half-wavelengths.