半潜式平台关键连接结构节点形式对疲劳强度的影响

以第七代半潜式钻井平台立柱与甲板盒连接结构为研究对象，给出3种能够改善立柱与甲板盒连接结构疲劳性能的设计方案，采用谱疲劳分析方法对3种改进的连接结构进行疲劳强度分析，并对关键区域肘板疲劳损伤对海况、浪向的敏感性进行分析，总结不同连接结构节点形式和焊接方式对疲劳寿命的影响，给出符合设计要求的较优的设计方案，为第七代超深水半潜式钻井平台立柱与甲板盒连接位置结构的设计提供依据与参考。

Influence of Critical Structure Joint Type on Fatigue Strength of Semi-Submersible Platform

Taken the critical joint structure between the vertical column and deck box of the seventh generation semi-submersible drilling platform as the study case, three design methods for the critical joint structure which can improve the fatigue performance are given. The fatigue strength of three improved critical joint structures is calculated by spectrum fatigue analysis method. The fatigue damage sensitivity of the critical joint structure to different sea conditions and wave directions is analyzed. The influence of different joint structure types and structure welding types on the fatigue life is summarized. The optimal design is provided based on the comparison result of fatigue strength. The optimal design could be applied to the critical joint structure design between the vertical column and the deck box of the seventh generation ultra-deep water semi-submersible drilling platform.