纳入裂尖位置实时预测的天然气管道裂纹扩展模拟方法  

Simulation method for crack propagation of natural gas pipelines with real-time prediction of crack tip position

作　　者：甄莹 常群[1,2] 曹宇光 祖毅真[1,2] 钮瑞艳 ZHEN Ying;CHANG Qun;CAO Yuguang;ZU Yizhen;NIU Ruiyan(College of Pipeline and Civil Engineering in China University of Petroleum(East China),Qingdao 266580,China;Shandong Province Key Laboratory of Safety of Oil&Gas Storage and Transportation in China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)储运与建筑工程学院,山东青岛266580 [2]中国石油大学(华东)山东省油气储运安全重点实验室,山东青岛266580

出　　处：《中国石油大学学报（自然科学版）》2022年第4期143-151,共9页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：山东省自然科学基金项目(ZR2020ME093);国家重点研发计划(2016YFC0802306,2016YFC0802105);中央高校基本科研业务费专项(21CX06049A)。

摘　　要：数值模拟是协助全尺寸管道爆破试验系统研究天然气管道断裂行为的有效手段。针对传统数值模拟方法无法随裂纹扩展实时调整裂尖前后管道内压分布导致断裂过程模拟不准确的问题,在归纳全尺寸管道爆破试验数据的基础上,提出管道裂纹动态扩展过程中裂尖位置随加载时间分阶段近线性变化的基本假设,结合气体减压模型构建纳入裂尖位置实时预测的迭代加载法。在基于管道全尺寸气体爆破试验结果探究该加载方法有效性的基础上,讨论迭代次数及气体减压模型类型对模拟结果的影响,形成纳入裂尖位置实时预测的天然气管道裂纹扩展模拟方法。结果表明,该模拟方法可有效实现加载边界随裂纹扩展的实时更新,近似实现气体减压、管道变形与裂纹扩展的多场耦合,模拟所得断裂参量、管道变形与试验结果一致性较好。Numerical simulation is an effective way to assist the full-scale pipeline burst experiment to study the fracture behaviors of the natural gas pipeline.Traditional loading methods are difficult to accurately predict the real-time internal pressure distribution before and after the crack tip when the crack propagates,resulting in inaccurate results.In order to solve this problem,a basic assumption that the crack tip position changes almost linearly with the loading time in different stages during the dynamic propagation of pipeline crack is put forward,on the basis of summarizing the experimental data of full-scale pipeline burst tests.Combined with the gas decompression model,an iterative loading method considering the prediction of the real-time crack tip position is proposed.The effectiveness of the loading method is explored based on the experimental results of the full-scale pipeline burst test.Then,the effects of the number of iterations and the gas decompression model on the simulation results are discussed.Finally,a simulation method for the dynamic crack propagation of natural gas pipelines with the real-time prediction of crack tip position is formed.The results show that the simulation method can effectively realize the real-time update of the loading boundary with the crack propagation,and the multi-field coupling of gas decompression,pipe deformation and crack propagation.The simulated fracture parameters and pipe s deformation are in good agreement with the experimental ones.

关 键 词：天然气管道 延性断裂 迭代加载 气体减压模型 Gurson-Tvergaard-Needleman(GTN)模型 

分 类 号：TE973[石油与天然气工程—石油机械设备]