Hybrid Laser-Arc Welding-Induced Distortion 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 6-10 mm in the construction of cruise ships. As one of the important processes of cruise ship construction, hybrid laser-arc welding, combining 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 4-16 m, 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 the 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. By analyzing the deformation behavior with the weld length of 5-15 m, when the continuous weld length exceeds 7.5 m during butt welding of large thin-walled cruise ship structures, the welding deformation mode will change from bending deformation to buckling deformation, while the maximum deformation will be reduced by about 50%. Compared with the buckling mode of the traditional thick-walled structures, with the decrease of plate thickness, the buckling mode of large ship structures will change from wave buckling deformation of the whole structure to wave buckling at the edge of structures.