Research on the magnetic flux leakage field distribution characteristics of defect in low-frequency electromagnetic detection technique
Research on the magnetic flux leakage field distribution characteristics of defect in low-frequency electromagnetic detection technique
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DOI：
10.1587/elex.17.20200362
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发表时间：
2021-01-10
影响因子：
0.8
通讯作者：
Bai, Shi
中科院分区：
文献类型：
--
作者：
Yang, Lijian;Huang, Ping;Bai, Shi
【摘要】：目的研究低频电磁检测技术(LFET)中油气管道缺陷低频漏磁(LF-MFL)场的分布特征。考虑矩形、半圆形、梯形、V形槽4种等长、等宽、不同底部形状的裂纹缺陷，基于磁偶极子理论，推导并建立了LF-MFL场的具体数学模型。实验结果表明，切向分量和法向分量上下包络差曲线的变化值与沿检测方向的缺陷截面积呈线性正相关，与底部形状和激励条件（幅度、频率和提离）严格无关。
This work aimed to investigate the distribution characteristics of the low-frequency magnetic flux leakage (LF-MFL) field of defect on oil and gas pipelines in low-frequency electromagnetic detection technique (LFET). Taking four types of crack defects (rectangular, semicircular, trapezoidal, and V-shaped grooves) with equal lengths, widths and different bottom shapes into consideration, the specific mathematical model of the LF-MFL field was inferred and established on the basis of magnetic dipole theory. Experimental results demonstrated that the variation values of the tangential and normal component upper-lower envelope difference curves were linearly positively correlated with the defect cross-sectional area along the detection direction, which was strictly independent of bottom shape and excitation conditions (amplitude, frequency and lift-off).