考虑翘曲应力的半潜平台扭转极限强度计算方法研究

半潜平台由于结构和受力复杂，目前主要采用非线性有限元整体模型计算其扭转极限承载力，存在建模和计算时间较长、精度较差和不易收敛等问题。一方面进行半潜平台的整体有限元模型的简化研究，提高其计算效率和收敛性；另一方面基于薄壁杆件理论，将该半潜平台截面简化为单壁室截面计算其翘曲应力，提出了基于一跨模型且考虑翘曲应力影响的半潜平台约束扭转极限强度计算的简化增量迭代方法，并编制了相应的计算程序。计算结果表明，所提简化增量迭代方法计算精度较高，能很好地反应翘曲应力对半潜平台约束扭转极限强度的影响，大幅减少了计算约束扭转极限强度的时间，可用于半潜平台的设计。

Investigate the methodologies for calculating the ultimate torsional strength of semi- submersible platforms considering warping stress

The semi-submersible platform, due to its intricate structure and force, primarily employs the nonlinear finite element model to compute its torsional ultimate bearing capacity. However, this approach presents challenges such as extended modeling and calculation times, reduced accuracy, and difficulty in convergence. To address these issues, this paper proposes a simplified finite element model for the semi-submersible platform, aiming to enhance its calculation efficiency and convergence. Additionally, the paper introduces a simplified incremental iteration method for calculating the constrained torsional ultimate strength of the semi-submersible, based on the one span model and taking into account the impact of warping stress. The corresponding calculation program is also developed. The results show that the proposed method offers high accuracy, effectively captures the influence of warping stress on the torsional ultimate strength of the semi-submersible platform, and significantly reduces the time required for calculating the torsional ultimate strength. This method can be utilized in the design of semi-submersible platforms.