面向20 MW规模超大浮式风机的钢板混凝土组合立柱设计尚处于探索阶段，其受力机制不明且缺乏理论认知与规范支撑。基于有限元方法对世界首台20 MW级钢板混凝土浮式风机立柱开展承载力极限状态的静力分析，结合强度理论研究立柱的内力分布并评估裂缝发展历程。结果表明，组合立柱结构整体表现出明显的主弯矩控制特征；当加载至设计荷载的 7% 时，混凝土十字舱板与钢平台连接的应力集中区局部混凝土开始退出工作。随着荷载增加至设计极限，最大裂缝宽度约0.11 mm，满足设计限值。研究明确该结构在设计极限荷载下的内力分布特征、裂缝发展过程及整体变形特性，结合参数敏感性分析，对于实际工程设计具有较为直接的指导意义。

The design of steel–concrete composite columns for 20 MW-scale floating wind turbines remains in the exploratory stage, with unclear load-bearing mechanisms and limited theoretical and regulatory guidance. In this study, a static finite element analysis of the ultimate load-bearing capacity was performed for the world’s first 20 MW steel–concrete composite floating wind turbine column. Based on strength theory, the internal force distribution and crack evolution of the column were investigated. The results show that the composite cylindrical structure exhibits distinct primary bending-moment-dominated behavior. When the load reached approximately 7% of the design limit, localized concrete in the stress concentration zone connecting the cross-deck slab and the steel platform began to cease contributing to load resistance. As the load increased to the design limit, the maximum crack width was about 0.11 mm, satisfying the allowable limit. The study elucidates the internal force characteristics, crack propagation process, and overall deformation behavior of the structure under ultimate loading. Combined with parameter sensitivity analysis, the findings provide direct guidance for practical engineering design.