Analysis of magnetic flux leakage signal characteristics of pipeline complex defects

管道复合缺陷漏磁信号特征分析 Analysis of magnetic flux leakage signal characteristics of pipeline complex defects 刘觉非 LIU Juefei 1 first-author 成文峰 CHENG Wenfeng 1 苏林 SU Lin 1 马梦想 MA Mengxiang 2 饶连涛 RAO Liantao 2 毛瑞麒 MAO Ruiqi 2 徐杰 XU Jie 2 corresp j.xu@cumt.edu.cn 国家管网集团东部原油储运有限公司管道检验检测中心 国家管网集团东部原油储运有限公司管道检验检测中心 Pipeline Inspection and Testing Center, East Crude Oil Storage and Transportation Co., Ltd.,State Pipeline Network Group Pipeline Inspection and Testing Center, East Crude Oil Storage and Transportation Co., Ltd.,State Pipeline Network Group 中国矿业大学材料与物理学院 中国矿业大学材料与物理学院 School of Materials and Physics, China University of Mining and Technology School of Materials and Physics, China University of Mining and Technology 基于漏磁检测技术基本原理,采用有限元方法,运用COMSOL软件对管道复合缺陷裂纹群和凹坑群的漏磁信号进行了仿真模拟。结果表明:对于裂纹群,随着裂纹条数的增加,磁通密度径向分量B x 峰值和轴向分量B y 幅值显著增大,且B x 峰值间距向两侧偏移,B y 波形宽度略有增大;当金属损失体积相同时,磁通密度径向分量和轴向分量峰值不仅与缺陷尺寸有关,还与缺陷分布形式相关。对于沿轴向和周向分布的复合凹坑,当凹坑相互叠加时,在凹坑重叠部分发生漏磁信号的变化;当凹坑相互分离,两凹坑的漏磁信号相互独立,且信号强度不随凹坑距离的继续增加发生明显变化。 Based on the basic principle of magnetic flux leakage（MFL） detection technology, the finite element method and COMSOL software were used to simulate the magnetic flux leakage signals of crack group and pit group with composite defects of pipeline. The results show that for the crack group, with the increase of crack strips, the amplitude of radial component B x and axial component B y of the flux density increase significantly, and the space of peak valuesof B x shifts to both sides, and the width of B y waveform increases slightly. When the metal loss volume is the same, the peak values of the radial and axial components of the flux density are not only related to the defect size, but also related to the defect distribution. For the compound pits distributed along the axial and circumferential directions, when the pits are superposed with each other, the magnetic flux leakage signal changes in the overlapping part of the pits. When the pits are separated from each other, the magnetic flux leakage signals of the two pits are independent of each other, and the signal strength does not change significantly with the increase of the pit distance. This provides a theoretical basis and reference for the analysis of the leakage signal characteristics of the defect group. 漏磁检测 管道复合缺陷 裂纹群 凹坑群 有限元模拟 magnetic flux leakage detection pipeline complex defects crack group pit group finite element simulation TG115.284 国家自然科学基金资助项目(51301197);江苏省自然科学基金资助项目(BK20130182) 2022-03-08 12 51