Cruise ships have large and long superstructures, which are almost extending the whole ship length with discontinuous characteristics, such as side shell recess and many window openings. The superstructure effectiveness on hull girder longitudinal strength is a complicated but unavoidable issue in ship design stage. This paper has carried out a collapse experiment of steel model with superstructures, which is designed based on one actual cruise ship. Critical factors including initial imperfections and welding residual stress used in nonlinear FE analysis have been validated by the experiment results. Then, the superstructure effectiveness is analyzed to revise the increment-iterative to be applicable for ultimate strength evaluation for cruise ships. At last the combination action of bending moment and shear force is studied, and a new combination formula is proposed. The conclusions in this paper will be useful for ship design, rules amendment and safety assessment for cruise ships.

游轮具有大型且较长的上层建筑，这些建筑几乎以不连续的特性延伸了整个船长，例如侧壳凹口和许多窗户开口。在船体设计阶段，上部结构对船体纵梁纵向强度的有效性是一个复杂但不可避免的问题。本文基于一艘实际的游轮设计了具有上部结构的钢模型的倒塌试验。实验结果验证了非线性有限元分析中使用的关键因素，包括初始缺陷和焊接残余应力。然后，分析上部结构的有效性，以修正增量迭代法，以适用于游轮的极限强度评估。最后研究了弯矩与剪力的组合作用，并提出了新的组合公式。本文的结论将对邮轮的船舶设计，规则修改和安全评估有用。