含缺陷深水夹层管非线性动态压溃机理研究

Sandwich pipe combining high structural resistance and thermal insulation has been considered as an effective solution for oil and gas transportation in ultra-deepwater. The collapse of sandwich pipe is a dynamic event caused by the hydrostatic pressure. A short duration pressure pulse which could destroy the pipeline and damage the adjacent structures can be observed during the dynamic collapse process. However, the present analysis method cannot resolve the highly nonlinear coupled fluid-structural interaction behavior. In this project, theoretical analysis, numerical simulation and experimental test are employed to investigate the dynamic collapse behavior of sandwich pipe with initial imperfections. The effects of the nonlinear fluid-structure interaction behavior, nonlinear geometric, large deformation, strain hardening and strain-rate hardening behaviors of material and contact interaction properties on dynamic collapse will be investigated. The distribution and variation of the pressure pulse and the coupling behavior between pressure pulse and post buckling deformation also will be discussed. The aim of this project is to find out the mechanisms of the dynamic collapse behavior of sandwich pipe with initial imperfection, to propose a comprehensive and systematic investigation methodology for dynamic collapse analysis, which will offer theoretical support for sandwich pipe design for oil and gas transportation in ultra-deepwater.

夹层管兼备良好的抗压与保温性能，成为高压低温环境下深水油气输运的理想选择。压溃是深水管道最为常见的失效形式，是包含高度非线性流固耦合行为的动态过程。压溃瞬间激发的压力脉冲会影响夹层管后屈曲变形行为，对周围管线安全构成威胁。目前针对该问题的研究无法揭示这种复杂的非线性动态行为，针对含缺陷深水夹层管的动态压溃问题仍没有现成的理论作指导。本项目将通过理论分析、数值模拟和实验研究相结合的手段，揭示含缺陷深水夹层管非线性动态压溃机理，探索非线性流固耦合行为、几何非线性、结构大变形、层间接触属性、材料应变以及应变率强化效应等因素对夹层管动态压溃行为的影响机制，研究夹层管周围压力脉冲的时空演变规律及其与后屈曲变形的相互作用，为深水夹层管设计提供必要的理论支持和技术指导。

夹层保温管能够抵抗深水高静水压力的同时兼备良好保温性能，在深水海洋油气工程领域具有较高的潜在应用价值。本项目围绕深水夹层管的压溃问题展开研究，建立了深水夹层管准静态与动态压溃数值模型，进行了全尺寸夹层管压溃实验研究，并利用实验结果对数值模型进行了验证，揭示了深水海底管道非线性动态压溃机理与瞬时压力脉冲时空变化规律，阐述了夹层管几何、材料参数对夹层管压溃行为的影响，提出了夹层管压溃载荷预测公式。在本项目的支持下，已在国内外高水平期刊发表论文11篇，其中SCI/EI检索论文6篇，录用待刊2篇，申请发明专利3项，其中已授权专利1项，获得2020年度海洋工程科学技术奖特等奖等科技奖励2项，培养硕博士研究生4人，参加高水平学术会议交流2次，邀请国外专家来校交流6次。