Abstract
Abstract Welding deformation in ship superstructures, particularly wave distortion on thin-plate external bulkheads, remains a persistent challenge affecting visual aesthetics and structural precision. Previous studies often focus on isolated mitigation techniques, lacking a systematic engineering approach. This paper presents a comprehensive methodology for welding deformation control in ship superstructures, bridging the gap between theoretical stiffness analysis and shipbuilding practice. Based on the theoretical relationship between plate rigidity, moment of inertia, and welding buckling, a hybrid strategy is proposed. This strategy integrates low heat-input processes (laser-arc hybrid welding and single-sided welding) to minimize initial thermal strain, with targeted stiffness enhancement measures. Specifically, local plate thickening at stress-concentrated corners and erection margins, the addition of vertical angle bars and flat bar stiffeners to optimize sectional inertia, the implementation of temporary channel steel bracing during lifting and transportation, and temporary platform for erection are systematically applied. The proposed methodology was implemented in the integrated construction of an oil tanker superstructure. Practical results demonstrate that this systematic approach significantly mitigates wave-like deformation and precludes lower-edge distortion with the planeness of the forward bulkhead from 7 to 4 mm per frame, without increasing the overall structural weight, offering a highly efficient and material-saving solution for modern shipbuilding. This study establishes a systematic connection between theoretical considerations and engineering practices of welding deformation control in ship superstructure.