高分辨焊缝漏磁检测数值模拟研究

Numerical Simulation Research on High-resolution Weld Magnetic Flux Leakage Inspection

基于漏磁检测原理,利用有限元对管道焊缝漏磁进行计算分析,分别研究探头提离和缺陷深度对漏磁场及其分布情况的影响。计算结果表明,探头提离对漏磁场信号值有很强的影响作用,随着探头提离的增大,漏磁场先快速减小后变化缓慢;改变焊缝上缺陷的深度,漏磁场强度会随着深度增加而增大。通过分析数值信号和探头提离的非线性关系,以及缺陷的漏磁信号在对称位置上的对称关系,可借此设计交错阵列排布的一种焊缝漏磁检测的高分辨探头。

Based on the principle of magnetic flux leakage detection,the finite element method is used to calculate and analyze the magnetic flux leakage of pipeline welds.The effects of probe lift-off and defect depth on the magnetic flux leakage and its distribution are studied respectively.The calculation results show that the probe lift-off has a strong effect on the value of the leakage magnetic field signal.With the increase of the probe lift-off,the leakage magnetic field first decreases rapidly and then changes slowly;changes the depth of the defect on the weld,and the strength of the leakage magnetic field Will increase as the depth increases.By analyzing the non-linear relationship between the numerical signal and the probe lift-off,as well as the symmetrical relationship between the magnetic flux leakage signal of the defect in the symmetrical position,we can design a high-resolution probe for weld flux leakage detection in a staggered array.