钢质悬链线立管力学特性与疲劳损伤分析-船舶与海洋结构物设计制造专业论文.docxVIP

上海交通大学硕士学位论文 摘要 万方数据 钢质悬链线立管力学特性与疲劳损伤分析 摘 要 随着深海油气资源的逐步开发，海洋立管的应用领域由浅水区向 深水区、极深水区发展。在深海服务区，其在受风浪流等复杂工况环 境下，经常遭受交变载荷作用，产生高阶模态振动，因而立管更易产 生疲劳损伤。本文对钢质悬链线立管(SCR)进行了力学特性研究，着 重研究了各种参数对疲劳损伤的影响。 首先介绍了悬链线立管和国内外在深海立管疲劳损伤方面的研 究现状和进展；重点应用有限差分法来对悬链线立管进行了静态分 析，研究了外部流速及边界条件对于立管变形的影响。 其次分析了悬链线立管的模态振动特性。把悬链线立管等效成顶 张式立管,比较不同计算方法对频率和振型计算精确度并进一步应用 有限单元法分析了顶端张力、顶端压强、管内流速等对于固有频率和 振型的关系。 再次，基于涡激振动计算软件SHEAR7，分析了悬链线立管弹性 模量、管内输液流速(通过等效变换，计算结果证明有效)、顶端张力、 顶端压强、流速剖面等诸多参数对立管涡激振动响应的特性和对疲劳 的影响。 最后针对钢悬链线立管易发生疲劳破坏的触地点处进行了数值 第 I 页  模拟，把立管视为弹性支撑在土体上的柔性管，分别用有限元软件、 有限差分法计算并分析了土壤特性、管径、壁厚等参数对触地点区域 弯曲应力及土体反力的影响。 关键词：钢质悬链线立管；有限差分法；有限单元法；涡激振动； 疲劳损伤；管-土相互作用 第 II 页 上海交通大学硕士学位论文 ABSTRACT Analysis of the Mechanical Characteristics and Fatigue Damage of SCR ABSTRACT As the gradual exploitation of deep sea oil resources, the riser has been taken into practice in the deep sea areas and even extra deep sea areas. Especially in the deep sea service region, it will always be subjected to complex environment loading, which yields high mode vibration and further is vulnerable to fatigue damage. This essay focuses on the mechanical characteristics and the factors relative to fatigue damage. The present research and future trend for fatigue damage of deep sea SCR are introduced at the beginning. Finite differential method is applied to amalyze the static deflection and the relation between deflection and dynamic boundary. Next, mode vibrations characteristics are analyzed. Finite element method is used to analyze the relation between top tension, top pressure, velocity inside the pipe and frequency and mode. Then, dynamic characteristics are analyzed based on software SHEAR7. The effects of elastic module，top tension, top pressure, velocity inside the pipe etc ,on RMS(Root-Mean-Square) stress and damage ration are calculated and analyzed. Last, the tube-soil interaction is simulated as a flexible pipe supported on a bed of springs. Deflections and bending stresses in the pipe are simulated based on Finite Element Method