Flaw Detection in Welded Metal Using Magnetic Induction Tomography

2014 ◽  
Vol 896 ◽  
pp. 722-725 ◽  
Author(s):  
Dona Sutisna ◽  
Syahrul Ullum ◽  
Warsito Purwo Taruno ◽  
Al Amin Saichul Iman ◽  
Marlin Ramadhan Baidillah ◽  
...  
Keyword(s):  
Magnetic Induction ◽  
Superposition Principle ◽  
Flaw Detection ◽  
Potential Method ◽  
Welded Steel ◽  
Radiographic Testing ◽  
Field Sensitivity ◽  
Experiment Method ◽  
Magnetic Induction Tomography ◽  
Non Destructive

Various defects on welded metal can lead to failure of material, so that it needs some routine examination to maintain the material quality. The development of Magnetic Induction Tomography (MIT) in recent years made MIT a potential method for Non Destructive Test (NDT) to be applied in industries. We perform an MIT inspection technique to detect flaw using 2-coils MIT planar sensor that consist of transmitter and receiver coils which is able to detect flaw based on different electrical conductivity and measured as phase shift. This study involves experiment method with measurement of welded steel in two areas, there are normal and defective welded area which amounts to 72 measurement points that conducted with superposition principle. Then simulation of 2-coils planar sensor using Finite Element Method (FEM) software to obtain magnetic field sensitivity using parameter as in the experiment. Result from this measurement showed that phase value in normal welded area is higher than defective welded area, then those data is processed further on reconstruction step by using specific algorithm to obtain reconstructed image. This image able to show the presence of flaw in welded area which is indicated by red spot, and it has a relatively good correlation when compared with radiographic testing film.

scholarly journals A Theoretical Model of Residual Magnetic Field around a Pre-Magnetized Casing String

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4226
Author(s):  
Yucai Shi ◽  
Dongyue Jia ◽  
Zhichuan Guan ◽  
Yuqiang Xu ◽  
Weixing Yang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Current Model ◽  
Superposition Principle ◽  
Potential Method ◽  
Detection Distance ◽  
Magnetic Field Model ◽  
The Individual ◽  
Magnetic Poles ◽  
Magnetic Induction Intensity

In the field of petroleum drilling engineering, passive magnetic ranging technology is generally used for specialized drilling operations such as connecting relief wells, preventing wellbore collisions, guiding parallel horizontal wells, etc. Although pre-magnetized casing strings have been used to improve the detection distance and accuracy, the theoretical mechanism is not well understood. Based on the equivalent current model of a permanent magnet, a theoretical magnetic field model around the pre-magnetized casing string was established by using the vector potential method and vector superposition principle and validated by the COMSOL Multiphysics software. Our results show that connecting pre-magnetized individual casings with homogeneous magnetic poles can enlarge the magnetic induction intensity around the total casing string. Furthermore, the magnitude close to the casing coupling is significantly larger than that close to the middle of the individual casing. Connecting pre-magnetized individual casings with heterogeneous magnetic poles results in a low magnetic induction intensity around the total casing string. In order to improve the detection distance and accuracy of the magnetic ranging, the pre-magnetized individual casings should be connected with homogeneous magnetic poles. The results of this study can provide guidelines for the development of passive magnetic ranging technology.

Inspection of defects in CFRP by improved magnetic induction tomography

2019 ◽  
Vol 61 (3) ◽  
pp. 255-259
Author(s):  
Lipan Zhang ◽  
Qifeng Meng ◽  
Kai Song ◽  
Ming Gao ◽  
Zhiyuan Cheng
Keyword(s):  
Magnetic Induction ◽  
Magnetic Induction Tomography

Image Reconstruction with the Fourier Coefficients for Magnetic Induction Tomography

2020 ◽  
Vol 16 (2) ◽  
pp. 156-163
Author(s):  
Jingwen Wang ◽  
Xu Wang ◽  
Dan Yang ◽  
Kaiyang Wang
Keyword(s):  
Inverse Problem ◽  
Image Reconstruction ◽  
Magnetic Induction ◽  
Fourier Coefficients ◽  
Signal Reconstruction ◽  
Reconstruction Algorithm ◽  
Reconstruction Method ◽  
Measurement Equation ◽  
Image Reconstruction Method ◽  
Magnetic Induction Tomography

Background: Image reconstruction of magnetic induction tomography (MIT) is a typical ill-posed inverse problem, which means that the measurements are always far from enough. Thus, MIT image reconstruction results using conventional algorithms such as linear back projection and Landweber often suffer from limitations such as low resolution and blurred edges. Methods: In this paper, based on the recent finite rate of innovation (FRI) framework, a novel image reconstruction method with MIT system is presented. Results: This is achieved through modeling and sampling the MIT signals in FRI framework, resulting in a few new measurements, namely, fourier coefficients. Because each new measurement contains all the pixel position and conductivity information of the dense phase medium, the illposed inverse problem can be improved, by rebuilding the MIT measurement equation with the measurement voltage and the new measurements. Finally, a sparsity-based signal reconstruction algorithm is presented to reconstruct the original MIT image signal, by solving this new measurement equation. Conclusion: Experiments show that the proposed method has better indicators such as image error and correlation coefficient. Therefore, it is a kind of MIT image reconstruction method with high accuracy.

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