复杂荷裁组合作用深海夹层管复合结构屈曲失稳机理研究

发布时间：2018-10-30 16:45

【摘要】：随着海洋油气资源开发向深海和超深海迈进,海底油气管道无疑面临着更大的风险与挑战,深海巨大的静水压力和低温环境对海底管道的承压能力,抗腐蚀能力和保温隔热能力都有较高要求。而传统单层管已无法满足深水和超深水海域管道的承载力和安全输运要求。一种新型的夹层管复合结构以其在深海油气资源开发和输运领域的显著的优势受到人们的广泛关注。深海油气管道在铺设和服役期间,需要承受轴向拉力、弯曲和外部高静水压力作用。夹层管的材料非线性和几何非线性加大了管道受力的复杂性,复杂的外部荷载下管道极易发生局部屈曲,屈曲沿管道轴向传递,导致管道的整体失稳破坏。夹层管复合结构在深海油气资源运输领域具有巨大的前景,对其在复杂荷载作用下的屈曲失稳机理展开研究具有重大的现实意义.本文通过试验测得夹芯层与内外管之间的黏结性能,并与数值模拟方法得到的结果进行对比。在考虑不同的层间黏结性能的基础上,对夹层管在复杂荷载组合作用下的屈曲失稳进行较为精确的数值模拟分析,具体研究工作主要为以下几个方面：(1)夹层管的层间黏结性能研究。本文通过剪切试件拉伸试验和夹层管段试件轴向推出试验,在接触面光滑和粗糙条件下,分别获得采用环氧树脂胶和3M-DP8005胶粘接的层间切应力-位移关系曲线。利用通用有限元软件ABAQUS分别建立两种试验的有限元模型,模拟试验过程进行计算,并与试验结果进行对比。(2)轴向拉力与弯曲组合作用下夹层管复合结构屈曲失稳研究。建立了夹层管复合结构在弯曲与拉力组合作用下的数值模型,采用节点间的非线性弹簧单元模拟夹层管轴向和环向的层间黏结性能,通过广泛的参数化分析,系统地阐述了加载路径、层间黏结性能、截面几何构型以及材料特性等因素对夹层管屈曲失稳的影响。(3)静水压力与弯曲组合作用下夹层管复合结构屈曲失稳研究。建立了夹层管复合结构在静水压力与弯曲组合作用下的数值模型,通过一系列参数敏感性分析,研究了加载路径、层间黏结性能、截面几何构型以及材料特性等因素对该荷载组合作用下夹层管屈曲失稳的影响机理。研究结果表明,复杂荷载组合作用下,加载路径对夹层管屈曲性能影响较为显著；相比传统单层管,夹层管的屈曲性能有较大幅度的提升；与截面初始几何缺陷相比,夹层管截面几何构型和内外管材料特性对夹层管屈曲性能影响较大。
[Abstract]:As the exploitation of offshore oil and gas resources moves towards the deep sea and the ultra deep sea, the submarine oil and gas pipelines are undoubtedly facing greater risks and challenges. The huge hydrostatic pressure in the deep sea and the pressure bearing capacity of the low temperature environment on the submarine pipelines, Corrosion resistance and thermal insulation have higher requirements. However, the traditional single-layer pipe can not meet the requirements of carrying capacity and safe transportation of pipelines in deep water and ultra deep water. A new sandwich pipe composite structure has attracted wide attention due to its remarkable advantages in the exploitation and transportation of deep-sea oil and gas resources. Deep-sea oil and gas pipelines need to be subjected to axial tension, bending and external high hydrostatic pressure during laying and service. The material nonlinearity and geometric nonlinearity of sandwich pipes increase the complexity of pipeline stress. The local buckling of pipes is easy to occur under complex external loads, and the buckling is transmitted along the pipeline axis, which leads to the overall instability and failure of pipelines. Sandwich pipe composite structure has a great prospect in the field of deep-sea oil and gas resource transportation. It is of great practical significance to study the buckling instability mechanism of sandwich pipe composite structure under complex loads. In this paper, the bonding properties between the sandwich layer and the inner and outer tubes are measured by experiments, and the results are compared with the results obtained by the numerical simulation method. On the basis of considering different interlaminar bonding properties, the buckling instability of sandwich tubes under complex load combination is analyzed by numerical simulation. The main works are as follows: (1) the interlaminar bonding properties of sandwich tubes. In this paper, the shear stress-displacement curves of epoxy resin adhesive and 3M-DP8005 adhesive are obtained under the condition of smooth and rough contact surface by tensile test of shear specimen and axial extrapolation test of sandwich tube piece. The finite element models of the two kinds of tests were established by using the universal finite element software ABAQUS, and the results were calculated by simulating the test process. (2) the buckling instability of sandwich tube composite structures under the combined action of axial tension and bending was studied. The numerical model of sandwich tube composite structure under the combination of bending and tension is established. The nonlinear spring element between nodes is used to simulate the interlaminar bonding performance of the sandwich tube in the axial and circumferential directions, and a wide range of parameterized analysis is carried out. The effects of loading path, interlaminar bonding properties, cross-section geometry and material characteristics on buckling instability of sandwich tube are systematically discussed. (3) buckling instability of sandwich tube composite structure under the combination of hydrostatic pressure and bending. The numerical model of sandwich tube composite structure under the combination of hydrostatic pressure and bending is established. Through a series of parameter sensitivity analysis, the loading path and interlaminar bonding properties are studied. The effect of geometrical configuration of section and material characteristics on buckling instability of sandwich tubes under the combined loads is investigated. The results show that the load path has a significant effect on the buckling behavior of sandwich tubes under the complex load combination, and the buckling behavior of sandwich tubes is greatly improved compared with the traditional single-layer tubes. Compared with the initial geometric defects of the sandwich tube, the geometric configuration of the sandwich tube section and the characteristics of the inner and outer tube materials have great influence on the buckling performance of the sandwich tube.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE973

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