摘要随着世界经济的迅猛发展，石油、天然气等传统能源的需求量逐年增长，而陆上资源的产量已不能满足日益增长的需要，各国开始大力发展海上石油的勘探、开采。海洋平台作为海洋油气探井、钻井、开采的主要作业基地，近年来得到了大力的发展。自升式钻井平台作为海洋平台的重要组成部分，在经历了半个多世纪发展后，在工作水深、抗风暴能力、可变载荷、钻井能力和操作性能等方面均取得了巨大进步，已成为目前应用最为广泛的移动式钻井设施，在深水钻井领域也发挥着越来越重要的作用。然而，海洋平台在海上长期工作，自然环境恶劣，如果遭受灾害性事故，不仅会威胁到人员的安全，也会导致巨大的经济损失及环境的污染。引起灾害性事故的主要原因来自船舶碰撞，其会造成海洋平台管桁架结构的严重损伤，特别是作为主要传力构件的管节点的破坏，具有很大的危害性。因此，本文以海洋平台中常见的T型节点为研究对象，分析其在受侧向撞击时的损伤变形机理及能量耗散机制，对更好的开展平台耐撞结构设计具有重要的现实意义。81903

本文通过模型试验、解析计算及数值仿真相结合的方法对冲击载荷下T型管节点的碰撞性能进行研究，提出相应的失效模式并得到能量耗散与撞深的关系。本文的主要研究内容及结论如下：

1、开展了自升式海洋平台T型管节点的落锤冲击试验，对试验中得到的碰撞力、冲击过程、损伤变形情况进行了分析讨论，研究了不同冲击高度对结构动态响应的影响规律。

2、基于试验建立了T型管节点的有限元模型并进行数值仿真分析，将仿真结果与实验结果进行比较，验证数值仿真方法的可靠性；基于数值计算结果，分析了典型冲击过程，探讨了不同冲击质量对管结构碰撞性能的影响规律。 

3、通过观察模型试验试件的损伤变形情况，提出T型节点的碰撞变形模式，并基于塑性理论，运用解析方法推导得到了冲击载荷下能量耗散的解析计算公式，将解析结果与数值仿真结果对比，从而验证解析计算的正确性。

毕业论文关键词：自升式海洋平台；碰撞；T型管节点；试验；解析计算；数值仿真

Abstract With the rapid development of the world economy, the demand for oil, natural gas and other traditional energy sources increased year by year, while the production of onshore resources can not meet the growing needs, countries began to develop offshore oil exploration。 As the main operating base of offshore oil and gas exploration, drilling, mining, offshore platforms in recent years have been a strong development。 Jack-up drilling platforms is an important part of the offshore platform。 After half a century of development, the working depth, anti-storm capacity, variable load capacity, drilling and operating performance  and other aspects have made great progress, it has become currently the most widely used mobile drilling facilities, also plays an increasingly important role the field of deep water drilling。 However, offshore platforms work in the sea for a long time and the marine environment is harsh。 If suffer from catastrophic accidents, it will threaten staff security, and may lead to economic lose and environment pollution。 The main cause of severe accidents is from the collision, which will cause serious structure damage of platform pipe truss, in particular joints which as the main force transmission member。 Therefore, selecting common T-joints of offshore platform as the research object, this article study the deformation mechanism and energy dissipation of T-joints under lateral impact is significant, which has important practical significance for crashworthiness design of offshore platform。