基于非接触力磁耦合效应的埋地管道现场检测试验与有限元仿真研究

发布时间：2018-03-03 01:02

  本文选题：非接触　切入点：埋地管道　出处：《东北石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：埋地管道在国家经济运行和人们日常生活中发挥着极其重要的作用,但却面临着十分突出的老化问题,加上运行环境复杂,一旦发生泄漏、爆炸,往往造成巨大的人员伤亡和经济损失,同时带来严重的环境污染,已经成为危害公共安全的重大隐患。对在役运行的埋地管道安全状况进行评价,实行全面开挖检测是不现实的,往往需要在非开挖的情况下非接触式检测。非接触磁记忆检测技术它能确定应力集中区-设备损伤发展的主要根源,为埋地管道在线非接触式磁记忆检测提供了理论基础。本文在现场试验检测的基础上,对不同埋深、内压和材质的埋地管道进行了检测分析和评估。在有缺陷的位置处,磁记忆信号表现为:切向分量和法向分量出现大幅度的下降或上升,梯度出现明显的往复性波动。对其有异常磁记忆信号的管道部位进行开挖,检测得知:在异常位置会出现泄漏、外腐蚀、内腐蚀。通过仿真软件对不同埋深、压力的埋地管道进行了有限元模拟和分析,得到了不同深度和不同压力下磁记忆信号的变换规律,不考虑焊接残余应力时,随内压增大,切向磁场强度峰值和法向磁场强度峰峰值均略有减小;随着埋深增大,切向磁场强度峰值和法向磁场强度峰峰值均不断减小;埋地管道内压对地面上非接触磁记忆信号影响远远小于埋深。在考虑了焊接残余应力时,进一步进行焊缝缺陷的多场耦合仿真,结果可以看出,相比于无缺陷时,无论是埋地部分的管顶、管中、管底,有缺陷管道的切向磁场强度峰峰值和法向磁场强度峰峰值均有所增大,且管上和管下的法向磁场强度信号发生反转。最后将有限元仿真结果与磁记忆检测试验结果进行对比,在有缺陷的位置,切向磁场强度和法向磁场强度的峰峰值均在不断增加,梯度由大幅度的变化,仿真的磁记忆信号与实际相符合,为埋地管道非接触式磁记忆检测与评价的实际工程应用提供基础性理论研究和方法依据。
[Abstract]:Buried pipelines play an extremely important role in the national economic operation and people's daily life, but they are faced with a very prominent aging problem, coupled with the complexity of the operating environment. Once leakage occurs, it explodes. It often causes huge casualties and economic losses, and at the same time brings serious environmental pollution, which has become a major hidden danger to public safety. The safety situation of buried pipelines in service is evaluated. It is not realistic to carry out full-scale excavation detection, which often requires non-contact detection under the condition of non-excavation. Non-contact magnetic memory detection technology can determine the stress concentration zone-the main source of equipment damage development. This paper provides a theoretical basis for on-line non-contact magnetic memory detection of buried pipelines. On the basis of field test, this paper analyzes and evaluates buried pipelines with different buried depths, internal pressure and materials. The magnetic memory signal shows that the tangential component and the normal component decrease or rise by a large margin, the gradient shows obvious reciprocating fluctuation, and the pipeline with abnormal magnetic memory signal is excavated. The detection results show that leakage, external corrosion and internal corrosion will occur in abnormal locations. Finite element simulation and analysis of buried pipelines with different buried depths and pressures are carried out by simulation software. The transformation law of magnetic memory signal at different depth and pressure is obtained. When welding residual stress is not considered, the peak value of tangential magnetic field intensity and the peak value of normal magnetic field intensity decrease slightly with the increase of internal pressure, and with the increase of buried depth, The peak value of tangential magnetic field intensity and the peak value of normal magnetic field intensity decrease continuously, and the influence of buried pipeline pressure on the non-contact magnetic memory signal on the ground is much smaller than that of buried depth. When welding residual stress is considered, The results show that, compared with those without defects, the pipe top, tube bottom and tube bottom of the buried part are different from those without defects. The peak value of tangential magnetic field intensity and the peak of normal magnetic field intensity are increased, and the normal magnetic field intensity signals on and under the tube are reversed. Finally, the finite element simulation results are compared with the results of magnetic memory test. In the defective position, the peak value of tangential magnetic field intensity and normal magnetic field intensity is increasing, the gradient varies greatly, and the simulated magnetic memory signal is in accordance with the actual situation. It provides the basic theoretical research and method basis for the practical engineering application of non-contact magnetic memory detection and evaluation of buried pipeline.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE973.6
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本文编号：1558849