半潜式平台关键结构选取及疲劳寿命计算

以南海某半潜式平台为研究对象，基于SESAM软件建立有限元模型，计算平台整体结构强度，筛选应力集中区域作为疲劳计算的关键区域。选取截面特征载荷，计算剖面载荷处的运动响应和长期预报幅值。在GeniE模块中，用SET分组的形式建立局部模型代替Submod模块使用的子模型计算，并对关键区域细化网格。在Stofat模块中计算节点处的疲劳损伤，根据S-N曲线计算疲劳寿命。结果表明，在平台关键区域1和区域2的节点疲劳损伤较大、寿命较短。因此，在半潜式平台服役期间，需要对关键结构部位进行定期检修和维护，以保证平台可正常运营。

Key Structure Selection and Fatigue Life Calculation of Semi-Submersible Platform

Taken a semi-submersible platform in the South China Sea as the research object, a finite element model is established based on the SESAM software, the overall structural strength of the platform is calculated, and the stress concentration areas are selected as the key areas for fatigue calculation. The section characteristic loads are selected, and the motion response and the long-term prediction amplitude at the section loads are calculated. In the GeniE module, the local model is established with the SET grouping to replace the submodel calculation used by the Submod module, and the grid in the key areas is refined. The fatigue damages at the nodes are calculated in the Stofat module, and the fatigue life is calculated according to the S-N curve. The results show that the fatigue damages of nodes in Key Area 1 and Key Area 2 of the platform are greater and their lives are shorter. Therefore, during the service of the semi-submersible platform, it is necessary to conduct the regular overhaul and maintenance of key structural parts to ensure the normal operation of the platform.