不同海域Semi平台关键节点的疲劳可靠性分析

为了确保深水半潜式平台(Semi平台)的安全可靠运行,对不同海域深水半潜式平台关键节点的疲劳可靠性进行研究.根据中国南海12个深水海域的波浪统计特征,利用水动力软件WAMIT计算平台疲劳分析的波浪荷载,进行不同工况下平台的应力响应分析,确定平台疲劳关键节点.采用改进的子模型技术分析局部精细子模型的应力响应,运用几何应力外插法计算各疲劳关键节点的热点应力.结合南海12个深水海域海况应用S-N曲线法分析平台各关键节点的疲劳可靠性.结果表明,12个深水海域平台各关键节点的疲劳可靠性指标各不相同,可以满足设计要求,78号海域对平台关键节点的疲劳可靠性影响最大,227号海域影响最小.研究结果可以为深水半潜式平台在南海海域作业时的运行维护和安全评估提供参考.

Fatigue reliability analysis on key nodes of a deepwater semi-submersible platform in different sea areas

In order to insure the safety and reliable service of deepwater semi-submersible platform (Semi), present study focuses on the fatigue reliability on key nodes of Semi. According to waves scatter diagrams of 12 seaareas in South China Sea, wave loads for the fatigue analysis were calculated by WAMIT, and the stresses responses of Semi in different sea-states were analyzed to determine the fatigue key nodes. The sub-model technology was used for the stresses analysis of local refined models, and the hot spot stresses of key nodes were calculated by using the extrapolation of geometric stress. Based on the S-N curve approach, the fatigue reliability analysis on key nodes was investigated. The results show that the fatigue reliability indices of key nodes are different in 12 seaareas, and all can satisfy with service requirements. NO.78 seaarea has the major influence on fatigue reliability of Semi, and NO.227 seaarea has a minimal impact. The results can be used as a reference for the operating maintenance and safety assessment of Semi during service in South China Sea.