复合材料海洋立管屈曲和止屈研究

发布时间：2019-01-17 13:31

【摘要】：随着社会的发展,能源在社会进步与发展中越来越重要,人们逐渐把目光投向广阔海洋的丰富资源。海洋立管是海上油气开采、运输的重要构件,且复合材料立管相对于金属立管具有柔韧性好、耐腐蚀、便于运输和安装等优点,成为海上油气管道的新选择。但因海洋工况恶劣复合材料立管相比于传统的钢管更容易在海洋环境下发生屈曲。因此,对其屈曲及止屈方法进行研究,对复合材料立管生产、安装、服役、维护有重要的理论意义和实用价值。本文为探究影响复合材料立管抗屈曲能力的因素,首先以非线性环理论、虚功原理为理论依据,建立适用于复合材料立管屈曲分析的模型。利用ANSYS和ABAQUS软件探究了几何尺寸(复合材料立管的长、径、厚)、复合材料铺层角和铺层数对复合材料立管抗屈曲能力的影响,并优化了复合材料立管模型尺寸。然后,为了使研究结果更加符合实际工况,在原有立管模型上分别施加三种初始缺陷:初始位移缺陷、初始椭圆率和分层缺陷,分别探究三种初始缺陷对复合材料立管抗面压屈曲能力的影响,以及每种初始缺陷对复合材料立管屈曲产生影响的机理。最后,结合上述研究结果,选择符合本文复合材料立管的灌浆粘结型止屈器,探究止屈器的作用效果及止屈原理,并探究在含有初始缺陷情况下的止屈器的作用效果,以此为止屈器的设计安装提供一定理论依据,也为复合材料立管的设计、安装、维护提供一定的理论指导。本文研究发现,立管越长、越薄立管抗屈曲能力越弱。立管铺层数越多,其抗屈曲能力越强。铺层角对立管的两种抗屈曲能力是对立的,在铺层角为50度左右时,立管的两种抗屈曲能力相对均衡。初始缺陷对立管的抗面压屈曲能力影响十分巨大,其影响立管抗屈曲能力的机理是:初始缺陷会使立管受外压时缺陷部分更易出现局部屈曲,然后屈曲扩展,传播至整个立管,使立管屈曲压溃。适当的止屈器对立管抗屈曲能力的提高有很大帮助。止屈器的作用机理为:止屈器阻断了局部屈曲的传播,使立管出现了高阶屈曲,增强了立管的抗面压屈曲能力,并且初始缺陷对止屈器的作用效果有一定的抑制作用。
[Abstract]:With the development of society, energy is becoming more and more important in social progress and development. Marine riser is an important component of offshore oil and gas exploitation and transportation, and composite riser has the advantages of good flexibility, corrosion resistance, easy transportation and installation compared with metal riser, so it has become a new choice for offshore oil and gas pipelines. However, composite risers are more prone to buckling in marine environment than traditional steel pipes. Therefore, it is of great theoretical and practical value to study the buckling and anti-buckling methods and to produce, install, service and maintain composite risers. In order to explore the factors affecting the buckling resistance of composite risers, a model for buckling analysis of composite risers is established based on nonlinear ring theory and virtual work principle. The effects of geometric dimension (length, diameter, thickness of composite riser), composite layer angle and number of layers on the buckling resistance of composite riser were investigated by using ANSYS and ABAQUS software, and the model size of composite riser was optimized. Then, in order to make the results more suitable to the actual working conditions, three kinds of initial defects were applied to the original riser model: initial displacement defect, initial ellipticity defect and delamination defect. The effects of three kinds of initial defects on the buckling ability of composite risers under plane compression and the mechanism of the effects of each initial defect on the buckling of composite risers were investigated. Finally, combined with the above research results, the effect of the anti-buckling device and the anti-buckling principle of the anti-buckling device are investigated, and the effect of the anti-buckling device in the case of initial defects is explored, which is suitable for the composite riser in this paper. So far, the design and installation of the bender provide some theoretical basis, and also provide some theoretical guidance for the design, installation and maintenance of composite riser. It is found that the longer the riser, the weaker the buckling resistance of riser. The more layers the riser has, the stronger the buckling resistance of riser is. The two kinds of anti-buckling ability of the laminated tube are opposite, and the two kinds of anti-buckling ability of the riser are relatively balanced when the stacking angle is about 50 degrees. The effect of the initial defect on the buckling ability of the riser is very great. The mechanism of the effect on the buckling ability of the riser is that the initial defect will make the defect part of the riser more prone to local buckling when it is subjected to external compression, and then the buckling will expand and spread to the whole riser. Cause the riser to buckle and crush. It is of great help to improve the buckling ability of the tube with proper buckling arrester. The mechanism of the anti-buckling device is that the buckling device blocks the propagation of local buckling and makes the riser appear high-order buckling, which enhances the anti-buckling ability of the riser, and the initial defect has a certain inhibitory effect on the anti-buckling effect of the riser.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P756.2

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