Practice Design of Ship Thin Section Considering Prevention of Welding-Induced Buckling

Abstract

_ The lightweight fabrication of thin-walled cabin sections is popular for advanced ships, and the dimensional tolerance generated by welding buckling significantly influences the fabrication accuracy and schedule with poststraightening. A typical thin section employed in the superstructure of a high-tech passenger ship is considered the research object. Conventional fabrication procedures and welding conditions were examined beforehand with combined thermal elastic-plastic and elastic FE computations based on the theory of welding inherent deformation, while welding buckling was represented with identical behavior compared with fabrication observation. Actually, there are usually two methods to prevent welding buckling with advanced fabrication. Stiffeners with optimized geometrical features and excellent elasticity moduli were assembled to enhance the rigidity of the ship thin section, and less welding inherent deformation with advanced welding methods can be employed to reduce mechanical loading. Computational results show that either less in-plane welding inherent strain or higher structural rigidity can reduce the magnitude of welding-induced buckling, and avoid the generation of welding-induced buckling during the lightweight fabrication. Introduction Recently, lightweight construction with thin-plate designs has become the highlight of advanced vehicles, such as ships, trains, and airplanes, particularly high-tech passenger vessels. Thin plate sections, as well as thin-walled structures with sufficient strength, exhibit excellent performance in enhancing the carrying capacity and protecting the environment with less fuel consumption. However, with the reduction in plate thickness for achieving lightweight design, welding-induced buckling can be generated owing to the lower stiffness as the most complex type of out-of-plane welding distortion (Wang et al. 2015, 2018). Buckling deformation will not only decrease fabrication accuracy and integrity but also increase cost and schedule; moreover, it influences mechanical performance, such as hydrodynamics. Unfortunately, it is hard to remove welding buckling after cooling to room temperature with flame heating or mechanical correction owing to its unstable features. Thus, it is preferable to reduce buckling distortion during the welding process by considering the practical design beforehand. Procedural parameters such as welding condition, heat efficiency, plate thickness, distribution of heat source, and stiffener spacing should be discussed because they influence the welding driving force and structural rigidity.