Magnetic flux leakage field within the detector unit optimization based on Comsol

2015 ◽  
pp. 271-276 ◽  
Author(s):  
L.J. Yang ◽  
W.T. Cui ◽  
S.W. Gao
Keyword(s):  
Magnetic Flux ◽  
Magnetic Flux Leakage ◽  
Leakage Field ◽  
Flux Leakage

Finite Element Analysis and Research on Corrosion Defect of Tank Floor

2016 ◽  
Vol 853 ◽  
pp. 514-518
Author(s):  
Zhi Jun Yang ◽  
De Shu Chen ◽  
Liang Chen ◽  
Yu Zhuo Liu ◽  
Ran An ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Magnetic Flux ◽  
Magnetic Flux Leakage ◽  
Bottom Plate ◽  
Element Analysis ◽  
Corrosion Defect ◽  
Leakage Magnetic Field ◽  
Leakage Field ◽  
Flux Leakage

Storage tank is an essential vessel in petrochemical industry, and the corrosion of tank is an important reason for the safety hazard. The corrosion of tank bottom plate is more serious than the tank wall, and it is not easy to check and repair, when damaged to a certain extent it will cause the leakage of the media, then lead to waste of energy, environmental pollution, at the same time it will cause a major accident. Magnetic flux leakage testing is widely used in the field of tank floor inspection with the advantages of fast scanning speed, accurate results and so on. In this paper, the finite element simulation and analysis of the corrosion defect leakage magnetic field is used to obtain the data, and the characteristic of the leakage magnetic field is extracted. The effect of defect depth and width and shape on the magnetic flux leakage field is studied, and the distribution curve of the magnetic flux leakage field is obtained.

Numerical Simulation and Experimental Research on Crack Magnetic Flux Leakage Field

2011 ◽  
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.

scholarly journals Investigation of and Components of the Magnetic Flux Leakage in Ferromagnetic Laminated Sample

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Mustafa Göktepe
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Crack Detection ◽  
Industrial Applications ◽  
Magnetic Flux Leakage ◽  
Longitudinal Magnetization ◽  
Flux Lines ◽  
Power Stations ◽  
Leakage Field ◽  
Flux Leakage

The magnetic flux leakage (MFL) technique is most commonly used for crack detection from iron bars, laminated sheets, and steel tubes of ferromagnetic nature. Magnetic flux leakage system induces a magnetic field and detects magnetic flux lines that “leak” or change because of a discontinuity in the magnetized area. An inductive coil sensor or a Hall effect sensor detects the leakage. Magnetic methods of nondestructive testing (NDT) depend on detecting this magnetic flux leakage field. The ferromagnetic specimen is magnetized by suitable methods, and flaws which break the surface or just the subsurface distort the magnetic field, causing local flux leakage fields. It is very important for industrial applications to detect cracks and flaws in metal parts of the steel bridges, power stations, military tools and structures, and so forth. In this study, the inspection of cracks in laminated sheets under longitudinal magnetization will be discussed in detail.

Magnetic Flux Leakage Sensing: Current Practices and Mathematical Analysis

2007 ◽  
Author(s):  
Sushant M. Dutta ◽  
Fathi H. Ghorbel
Keyword(s):  
Magnetic Flux ◽  
Magnetic Flux Leakage ◽  
Defect Characterization ◽  
3 Dimensional ◽  
Hall Effect Sensor ◽  
Leakage Field ◽  
Lift Off ◽  
Flux Leakage ◽  
Insight Into ◽  
Current Practices

In this paper, we analyze magnetic flux leakage (MFL) sensing for the nondestructive evaluation (NDE) of ferromagnetic specimens. Understanding the processes involved in the creation of magnetic flux leakage fields and their measurement is critical to robotic inspection applications. In particular, robotic inspection of energy pipelines uses mobile robots to magnetize sections of the pipe and to measure the MFL signal to detect defects. We study current practices and motivate the need for improvements. To facilitate the analysis, we develop an analytical model to represent the 3-dimensional magnetic flux leakage field due to a surface-breaking defect in the specimen. The model is derived from first principles using the concept of dipole magnetic charge, and uses surface integrals to represent the MFL field as measured by a Hall-effect sensor. Simulations are performed which generate novel results, apart from reproducing experimental results from the literature. The mathematical tractability of the model is exploited to analyze its properties, such as scale–invariance, influence of lift-off, and the tangential MFL component. These properties give new insight into MFL sensing, interpretation, and defect characterization.

scholarly journals Tensor Based Finite Element Model for the Calculation of Leakage Field in Magnetic Flux Leakage Testing

2020 ◽  
Author(s):  
Fred John Alimey ◽  
Libing Bai ◽  
Yuhua Cheng
Keyword(s):  
Magnetic Flux ◽  
Surface Defects ◽  
Element Model ◽  
Single Equation ◽  
Magnetic Flux Leakage ◽  
Leakage Field ◽  
Proposed Model ◽  
Defect Area ◽  
Mathematical Operations ◽  
Flux Leakage

Magnetic flux leakage (MFL) testing is a widely used electromagnetic nondestructive testing (ENDT) method, which has the ability to detect both surface and sub-surface defects in conductive materials. One of its best features is its ability to mathematically model field leakage from the defect area in a magnetized material. In this paper, we propose an optimized FEM model using geometrical weighted tensor (TBFEM), for the calculation of leakage field in MFL. This model using the Einstein’s convention eliminates the bulky nature of traditional FEM based on its matrix algebra formation allowing for easy implementation and fast calculations. The proposed model achieves this by reducing the set of matrix equations into a single equation using suffixes which can then be solved with regular mathematical operations.

Analysis of Defect Magnetic Flux Leakage Field Based on Dipole

2013 ◽  
Vol 274 ◽  
pp. 592-595
Author(s):  
Jun Shan Gao ◽  
Jin Wang ◽  
Ke Wang
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Magnetic Field Intensity ◽  
Magnetic Flux Leakage ◽  
Defect Model ◽  
Leakage Field ◽  
Ellipsoidal Model ◽  
The Magnetic Field ◽  
Flux Leakage ◽  
Common Defect

This paper makes an exhaustive analysis to common defect magnetic leakage field based on dipole theory, obtaining the analytical expression of some common injury shapes and exploiting distribution curves of the magnetic field intensity by MATLAB software, and based on this a new scheme is proposed to simulate various injuries using an ellipsoid tables defect model, and finally confirms the superiority of ellipsoidal model in analysis of defect leakage field by comparison.

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