Quantitative Detection of Wire Rope Based on Three-Dimensional Magnetic Flux Leakage Color Imaging Technology

Magnetic flux leakage (MFL) is a non-destructive testing method used to inspect ferrous materials. However, apparatus parameters could affect the MFL inspection tool’s ability to characterize anomalies. In this paper, MFL signals obtained during the inspection of pipes have been simulated using three-dimensional finite element analysis and the effects of magnet assembly on MFL signals are investigated. According to numerical simulations, an increase in the leakage flux amplitude is observed with an increase in the permanent magnet size and the inflexion point may indicate the presence of magnetizing pipe wall to near saturation. It clearly illustrates degradation in the MFL with increasing backing iron length. The relationship between MFL apparatus parameters and MFL signals could be utilized in the MFL technique to characterize the defect.

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Algorithm Considering Signal Correlation for Denoising of the Magnetic Flux Leakage of Wire Rope

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.291-294.2652 ◽

2011 ◽

Vol 291-294 ◽

pp. 2652-2657 ◽

Cited By ~ 3

Author(s):

Wei Xia Zhan ◽

Ji Wen Tan ◽

Yan Wen

Keyword(s):

Magnetic Flux ◽

Correlation Coefficient ◽

Local Features ◽

Wire Rope ◽

Magnetic Flux Leakage ◽

Original Signal ◽

Processing Effect ◽

Flux Leakage ◽

Signal Correlation

In order to suppress the noise in the magnetic flux leakage, the algorithm considering signal correlation, in which an optimal predictor and an optimal updater were chosen for every sample at all scales according to the magnitude of the correlation coefficient, was proposed. So the wavelets obtained through designing predictor and updater can perfectly fit the local features of signal. The actually processing effect of the simulation and the magnetic flux leakage signal of damage in wire rope show that the proposed method, compared with the classical wavelet, can effectively remove noise in original signal and principally retain the local features of the original signal.

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Numerical Simulation and Experimental Research on Crack Magnetic Flux Leakage Field

ASME 2011 Pressure Vessels and Piping Conference: Volume 1 ◽

10.1115/pvp2011-57514 ◽

2011 ◽

Cited By ~ 1

Author(s):

Fujun Liu ◽

Mulin Zheng ◽

Shuai Kong ◽

Zhangwei Ling ◽

Yueqiang Qian

Keyword(s):

Numerical Simulation ◽

Magnetic Flux ◽

Experimental Research ◽

Inclination Angle ◽

Three Dimensional ◽

Magnetic Flux Leakage ◽

Experimental Investigations ◽

Leakage Field ◽

Three Dimensional Models ◽

Flux Leakage

Magnetic flux leakage (MFL) testing is widely used to inspect and characterize defects in pipelines, storage tanks and other structures. In this paper, based on the Maxwell Equations, numerical simulation and experimental research of crack magnetic flux leakage field were carried out. The three-dimensional models of cracks were established, the influence of the generalized crack parameters to the magnetostatic MFL field, including depth, width, inclination angle and crack spacing, was discussed. The relationship between defect parameters and MFL amplitude was obtained. The amplitude is significantly affected by the inclination angle. Therefore, single direction inspection may lead to undetected in practice. While the two cracks interval is less than 5 mm, the MFL fields would overlap. Furthermore, the experimental investigations were developed, and the results agree well with that of the simulation. The conclusions could provide valuable reference for inspection.

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