深海夹层管复合结构非线性屈曲传播机理与止屈控制研究

Due to low temperature and high hydrostatic pressure in deep waters, the oil-gas pipelines should have excellent thermal insulation properties. With high load-carrying capacity and good thermal insulation properties, sandwich pipes consisting of an inner and outer metallic pipe with a lightweight thermal insulation material in the annulus, have been used in deepwater oil-gas resource development in recent years. But high hydrostatic pressure in deep waters easily leads to local failure of pipe structures, the buckle may propagate along the pipeline at a high speed, collasping the whole pipeline. The sandwich pipe, being a composite structure, brings a great challenge to precisely decribe its buckle propagation characteristics and develop buckle arresting control techniques. So far there is little existing research and specification involved. In this project, the combined methods of theoretical model analysis, deep-sea pressure cylinder scale model experements and numerical simulations are applied to study non-linear buckle propagation characteristics of sandwich pipes. The present study aims to profoundly explore the influencing mechanisms of buckle propagation and buckle crossing arrestors for the composite structures of sandwich pipes under high external hydrostatic pressure, and systematically reveal the intrinsic relationships between buckle propagation pressure and deformed shape, buckle crossover pressure and mode for different types of buckle arrestors, and structure and material properties, as well as interlayer adhesion properties, and respectivley estabilsh therecial calculation models of buckle propagation pressure of deep-sea sandwich pipes and buckle crossover pressure of corresponding buckle arrestors, and finally bring forth arresting effeciency assessment and design theory of buckle arrestors. The research findings will offer a solid theoretical foundation for buckle arresting controls of deep-sea sandwich pipes.

低温高压环境决定深海油气管道需要具有较好的保温绝热性能。由内层输送钢管、外层保护钢管以及两管环形空间轻质保温绝热材料构成的夹层管，由于具有较高的承载能力和良好的保温绝热性能，近年来已应用于深海油气资源开发中。但深海高压环境容易诱发管道屈曲，并沿轴向传播，导致整条管道失稳破坏。而深海夹层管是一种复合结构，准确描述其屈曲传播特性并开展止屈控制具有较大的挑战性，迄今为止研究和规范鲜有涉及。本项目拟通过理论分析、深海压力缸比例模型试验和数值模拟相结合研究夹层管的非线性屈曲传播特性，旨在探索高静水压力作用夹层管复合结构屈曲传播与屈曲穿越止屈器的影响机理，揭示深海夹层管屈曲传播压力和变形形态、止屈器屈曲穿越压力和穿越模式与结构、材料特性和层间粘接性能之间的内在关系，建立深海夹层管屈曲传播压力和止屈器屈曲穿越压力的理论计算模型，形成止屈器止屈效率评估及设计理论，为深海夹层管的止屈控制奠定坚实的理论基础。

海底管道是海洋油气资源开发利用的生命线，是海洋油气运输最为经济有效的载具。随着海洋油气资源勘探开发逐渐向深水和超深水海域进军，深海低温高压环境易诱发管道的屈曲失稳，并沿轴向传播，导致整条管道失稳破坏。由内层输送钢管、外层保护钢管以及两管环形空间填充轻质保温绝热材料构成的夹层管，由于具有良好的保温绝热性能和较高的承载能力，近年来已应用于深海油气资源开发中。在深海高压作用下夹层管复合结构的屈曲失稳、屈曲传播以及止屈控制，迄今为止国内外研究鲜有涉及。本项目充分明确了深海夹层管的屈曲失稳、屈曲传播和屈曲穿越整体式止屈器的影响机理，系统深入揭示了夹层管屈曲传播压力和变形形态、整体式止屈器屈曲穿越压力和穿越模式与结构、材料力学特性和层间黏结性能之间的内在关系，提出了夹层管屈曲传播压力和整体式止屈器屈曲穿越压力的经验预测公式，形成了整体式止屈器止屈效率理论评估模型，为深海夹层管的止屈控制提供了坚实的理论基础。研究成果已在国际期刊发表SCI论文6篇，国内期刊发表EI论文3篇，国际会议论文2篇，授权软件著作权1项。培养已毕业博士3人，硕士3人。