Concerning the exact solution for an internal transmit-receive eddy current probe at arbitrary locations and orientations within two non-concentric conductive tubes

Luloff, Mark S.

doi:10.1016/j.ndteint.2020.102298

Cited by 5 publications

(3 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…What poses a real challenge is the determination of complex eigenvalues when the region under consideration consists of several sub-regions (containing conductive material or air). Such a situation occurs when modeling disks [ 8 , 9 , 10 , 11 ], tubes [ 12 , 13 , 14 , 15 , 16 ], rods [ 17 , 18 ], materials with a defect [ 19 , 20 , 21 , 22 , 23 , 24 ], and wherever there are edges [ 25 , 26 , 27 , 28 , 29 ] or discontinuities [ 30 , 31 , 32 ] ( Figure 1 ). Determination of the eigenvalues then boils down to finding complex roots of the appropriate complex function.…”

Section: Introductionmentioning

confidence: 99%

Computation of Eigenvalues and Eigenfunctions in the Solution of Eddy Current Problems

Theodoulidis

Skarlatos

Tytko

2023

Sensors

View full text Add to dashboard Cite

The solution of the eigenvalue problem in bounded domains with planar and cylindrical stratification is a necessary preliminary task for the construction of modal solutions to canonical problems with discontinuities. The computation of the complex eigenvalue spectrum must be very accurate since losing or misplacing one of the thereto linked modes will have an important impact on the field solution. The approach followed in a number of previous works is to construct the corresponding transcendental equation and locate its roots in the complex plane using the Newton–Raphson method or Cauchy-integral-based techniques. Nevertheless, this approach is cumbersome, and its numerical stability decreases dramatically with the number of layers. An alternative, approach consists in the numerical evaluation of the matrix eigenvalues for the weak formulation for the respective 1D Sturm–Liouville problem using linear algebra tools. An arbitrary number of layers can thus be easily and robustly treated, with continuous material gradients being a limiting case. Although this approach is often used in high frequency studies involving wave propagation, this is the first time that has been used for the induction problem arising in an eddy current inspection situation. The developed method is implemented in Matlab and is used to deal with the following problems: magnetic material with a hole, a magnetic cylinder, and a magnetic ring. In all the conducted tests, the results are obtained in a very short time, without missing a single eigenvalue.

show abstract

Section: Introductionmentioning

confidence: 99%

Computation of Eigenvalues and Eigenfunctions in the Solution of Eddy Current Problems

Theodoulidis

Skarlatos

Tytko

2023

Sensors

View full text Add to dashboard Cite

show abstract

“…The model showed good accordance with finite element method (FEM) and required less computational time. Luloff et al [4] developed a more general parallel plates model for gap measurement, with probe tilt relative to the PT considered. In addition, all electromagnetic coupling coefficients produced by the probe and layered conductors, which were used for calculating the induced voltage of receive coil, were determined.…”

Section: Introductionmentioning

confidence: 99%

“…Both the RFEC method in [1] and the multi-frequency eddy current method in [2][3][4][5][6] proposed for gap measurement of metal casing belong to the sinusoidal eddy current method excited by a sinusoidal current. The main purpose of this paper is to theoretically compare the detection sensitivity of sinusoidal eddy current method and pulsed eddy current method for the casing gap measurement.…”

Section: Introductionmentioning

confidence: 99%

Pulsed eddy current testing for gap measurement of metal casing

Chen¹,

Niu²

2022

Meas. Sci. Technol.

View full text Add to dashboard Cite

A pulsed eddy current testing (PECT) method is proposed to measure the gap of non-ferromagnetic metal casing. Firstly, the detection sensitivity to the casing gap of the voltage signal induced respectively by time-harmonic excitation current and by pulsed excitation current are calculated theoretically and compared. Then the advantages of PECT method for gap measurement are discussed. Secondly, the difference curve of the time-domain induced voltage signal between two gaps near the nominal value is presented. And the value of the induced voltage signal corresponding to the peak time of the difference curve is extracted to serve as the signal characteristic. Furthermore, using a calibrated casing, the function relationship between the signal characteristic and the casing gap is derived by curve fitting. Finally, the casing gap can be determined rapidly through the induced voltage at the peak time. This paper provides a reliable non-destructive testing method for the casing gap measurement, and compared with the existing sinusoidal eddy current testing method, the PECT method can significantly improve the signal-to-noise ratio and the detection sensitivity to the casing gap.

show abstract

A novel circumferential eccentric eddy current probe and its application for defect detection of small-diameter tubes

Yang

Xie

et al. 2021

Sensors and Actuators A: Physical

View full text Add to dashboard Cite

Concerning the exact solution for an internal transmit-receive eddy current probe at arbitrary locations and orientations within two non-concentric conductive tubes

Cited by 5 publications

References 13 publications

Computation of Eigenvalues and Eigenfunctions in the Solution of Eddy Current Problems

Computation of Eigenvalues and Eigenfunctions in the Solution of Eddy Current Problems

Pulsed eddy current testing for gap measurement of metal casing

A novel circumferential eccentric eddy current probe and its application for defect detection of small-diameter tubes

Contact Info

Product

Resources

About