2022年北溪天然气管道泄漏事件引起了全世界的广泛关注。建立了北溪天然气管道的有限元分析（finite element analysis，简称FEA）模型，使用LS-DYNA求解器和ALE (arbitrary Lagrangian-Eulerian) 算法模拟了水下爆炸及管道破坏的全过程，并通过了模型验证。参考北溪管道事件中泄漏点的实地拍摄照片，通过有限元分析实现了事故反演，并从中分析推断得出造成北溪一号和北溪二号管道泄漏的可能原因。研究明晰了内部承压海底管道在水下爆炸作用下毁伤的3个阶段：爆炸冲击阶段、内压泄漏阶段和稳定阶段。引入中空夹层复合海底管道结构形式，并对其进行了水下爆炸的有限元分析。分析结果显示，新型结构相比于常用的单层管道形式，可显著提升其抗爆和可修复性能，为相关海底管道抗爆设计提供优选结构形式。
英文摘要:
The Nord Stream gas pipeline leakage accident in 2022 has raised global concern. In this study, a finite element analysis(FEA) model of the Nord Stream gas pipelines is established. The LS-DYNA solver and the ALE (arbitrary Lagrangian-Eulerian) algorithm are used to simulate the entire process of the underwater explosion and pipeline damage, and the model is validated. Referring to on-site photographs of the Nord Stream pipeline leaks, numerical inversion is conducted, from which the possible causes of the Nord Stream 1 and Nord Stream 2 leakages are deduced. The study clarifies three stages of damage to internally pressurized submarine pipelines under underwater explosions: explosion shock stage, decompression stage, and stabilization stage. Finally, the concrete-filled double-skin composite pipeline (CFDSP) structure is introduced, and a FEA of the underwater explosion is performed. The analysis results show that the CFDSP structure provides significantly better blast resistance and reparability than conventional single-layer pipelines, offering a promising structural option for submarine pipeline blast-resistant design.
