海洋非粘结柔性管压溃理论分析及数值模拟研究

发布时间：2018-06-15 05:38

本文选题：非粘结柔性管 + 骨架层　；参考：《中国海洋大学》2015年硕士论文

【摘要】：非粘结柔性管是海洋油气勘探开采中的重要装备,是由金属材料层和聚合物材料层以不粘结的形式组合形成,允许管道层与层之间发生相对滑动。相对于其它形式的海洋管道,柔性管有更优的结构力学性能,更加适用于深海的油气开发。当今,海洋石油开发逐渐走向深海,海洋环境也越来越复杂,使得位于管道结构最内部的骨架层可能承受过大的静水外压,造成管体破裂,产生压溃失效。在实际工程中,由于制造缺陷、张紧器作用等影响,管道的骨架层不可避免地存在初始椭圆度,难以达到完美圆状态,而骨架层主要由钢材制成,其材料的非线性可能对其抗压溃能力产生影响,同时骨架层相邻表面之间的相对滑动也会对柔性管结构的强度产生一定的影响。但在现有的理论研究方法中通常假定骨架层相邻表面间没有相对滑动,并且忽略了初始椭圆度和材料非线性对压溃失效特性的影响,使得研究结果应用到实际工程时有一定的偏差。针对上述缺陷,本文首先介绍骨架层结构形式和特点,并对压溃失效机理、行业设计规范中关于压溃设计的要求以及非粘结柔性管压溃的理论计算模型进行了详细总结。在此基础上,基于有限元分析方法,分别采用三种接触方式对8寸内直径骨架层进行建模,对模型在完美圆状态、存在初始椭圆度几何缺陷状态和考虑材料弹塑性状态三种情况下的径向位移值和临界压溃值进行计算,并通过与理论计算结果的对比和讨论,研究非粘结柔性管的压溃行为,得到了相应的结论,对非粘结柔性管道压溃分析研究有一定的借鉴意义。
[Abstract]:Unbonded flexible pipe is an important equipment in offshore oil and gas exploration and exploitation. It is formed by the combination of metal material layer and polymer material layer in the form of unbonding, allowing relative sliding between pipeline layers and layers. Compared with other types of offshore pipelines, flexible pipes have better structural and mechanical properties and are more suitable for oil and gas exploitation in the deep sea. Nowadays, the offshore oil development is gradually moving to the deep sea, and the marine environment is becoming more and more complex, which makes the skeleton layer in the most inner part of the pipeline structure likely to bear excessive hydrostatic external pressure, resulting in the rupture of the pipe body and the collapse failure. In practical engineering, due to the influence of manufacturing defects and tensioning, the initial ellipticity of the skeleton layer of the pipeline is unavoidable, which is difficult to reach the perfect circle state, and the skeleton layer is mainly made of steel. The nonlinearity of the material may have an effect on the strength of the flexible tube structure, and the relative sliding between the adjacent surfaces of the skeleton layer will also affect the strength of the flexible tube structure. However, in the existing theoretical research methods, it is generally assumed that there is no relative sliding between adjacent surfaces of the skeleton layer, and the effects of initial ellipticity and material nonlinearity on the collapsing failure characteristics are ignored. It makes the research result have certain deviation when it is applied to the actual project. In view of the above defects, this paper first introduces the structure form and characteristics of skeleton layer, and summarizes the failure mechanism of crushing layer, the requirements of crushing design in industry design code and the theoretical calculation model of unbonded flexible pipe crashing. On this basis, based on the finite element analysis method, three kinds of contact methods are used to model the 8 inch inner diameter skeleton layer, and the model is in perfect circle state. The radial displacement value and critical collapse value are calculated under the condition of initial ellipticity geometric defect state and elastic-plastic state of material. The collapsing behavior of unbonded flexible pipe is studied by comparing and discussing with the theoretical calculation results. The corresponding conclusions are obtained, which can be used for reference in the analysis and research of non-bonded flexible pipeline collapse.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE95

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