中文摘要：

为了对大型结构如海洋平台的疲劳可靠性进行准确的评价并减小计算工作量,针对海洋平台在疲劳可靠度计算过程中存在的诸多不确定性,如环境的复杂性、载荷的高突发性、强随机性和强可变性及在力学分析中的复杂重复工作等问题,提出了基于子结构法的海洋平台疲劳可靠性评价方法。它先采用子结构法将复杂的海洋平台模型简化,对构件层次和失效模式进行划分,然后对不同构件层次和失效模式的可靠度进行了计算,最后对各个子结构的疲劳可靠度进行组合得到海洋平台的整体可靠度。为了验证所提方法的可行性和有效性,分别对一个平面桁架和导管架型海洋平台进行了疲劳可靠度计算。研究发现,本文所提方法不仅可以简化大型结构的复杂程度,减小疲劳计算的工作量,而且在一定程度上可提高计算精度。

英文摘要：

In order to accurately evaluate the fatigue reliability of offshore platforms and reduce the analytical efforts,such as environmental complexity,loads frequent outburst,high randomicity and reanalysis during fatigue analysis,a new fatigue reliability method based on substructure for offshore platform is proposed.The substructure method is employed to simplify a jacket offshore platform,and it is divided into different failure modes and critical members first.Then the fatigue reliability of all substructures is analyzed and the fatigue reliability of the integrated structure is assessed finally.To validate the proposed method,the fatigue reliability of a planar truss and a jacket offshore platform are analyzed,respectively.The results show that the proposed method can not only simplify the complexity of large structures and reduce fatigue analytical efforts,but also improve the analytical precision to some extent.