Journal ArticleDOI
Planar rectangular spiral coils in eddy-current non-destructive inspection
R.J. Ditchburn,S.K. Burke +1 more
TLDR
In this paper, the results of a theoretical and experimental study of planar rectangular coils in eddy-current NDE are presented, and closed-form expressions for the coil impedance are presented for these three cases and the theoretical predictions are validated against experiment using a series of coils with different aspect ratios and both non-magnetic and magnetic plates.Abstract:
The results of a theoretical and experimental study of planar rectangular coils in eddy-current NDE are presented. Three fundamental cases are examined: a planar coil (i) in free space, (ii) above a defect-free conductive half-space and (iii) centered above a long, uniform crack. Closed-form expressions for the coil impedance are presented for these three cases and the theoretical predictions are validated against experiment using a series of coils with different aspect ratios and both non-magnetic and magnetic plates. While the change in normalized coil impedance due to the half-space depends only weakly on the coil aspect ratio, the change in normalized impedance due to the crack depends strongly on coil aspect ratio with the maximum normalized response observed for an aspect ratio of 1:1, i.e. for square coils. In contrast to planar circular coils, the response of planar rectangular coils depends on their orientation with respect to the crack. This orientation dependence is investigated in detail.read more
Citations
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Journal ArticleDOI
A differential planar eddy currents probe: Fundamentals, modeling and experimental evaluation
TL;DR: In this article, a planar probe with a differential operation was proposed to inspect imperfections along Friction Stir Welding joints, which was validated experimentally using an aluminum alloy block with standard defects produced using electro-discharge machining.
Journal ArticleDOI
The Improvement of Flaw Detection by the Configuration of Uniform Eddy Current Probes
Ageng S. Repelianto,Naoya Kasai +1 more
TL;DR: In this review, the principles to detect flaws with uniform eddy currents were presented based on the shape and orientation of the excitation coils and detection coils of the probe.
Journal ArticleDOI
Multilayer planar rectangular coils for eddy current testing: Design considerations
TL;DR: In this article, the second-order vector potential approximation (SOP) was used to estimate the impedance of planar rectangular coils in free space and on a conductive substrate.
Journal ArticleDOI
Present and Future Impact of Magnetic Sensors in NDE
Helena G. Ramos,A. Lopes Ribeiro +1 more
TL;DR: In this paper, the authors present a survey of magnetic field sensing elements and present the advantages and drawbacks of each class of magnetic sensing technology when applied to an electromagnetic method involving magnetic field measurement.
Journal ArticleDOI
Electrical conductivity field analysis for evaluation of FSW joints in AA6013 and AA7075 alloys
TL;DR: In this paper, an eddy current planar probe was used for the measurements at different depths of friction stir welds and a close match between the electrical conductivity field and the microstructure was observed.
References
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BookDOI
Review of Progress in Quantitative Nondestructive Evaluation
TL;DR: The Review of Progress in Quantitative NDE (ROPQN) as mentioned in this paper is the world's leading conference in reporting annually new research and development results in quantitative NDE and promotes communication between the research and engineering communities and emphasize current reporting of work in progress.
Journal ArticleDOI
Simple accurate expressions for planar spiral inductances
TL;DR: In this paper, the authors present simple and accurate expressions for the DC inductance of square, hexagonal, octagonal, and circular spiral inductors, and evaluate the accuracy of their expressions, as well as several previously published inductance expressions, in two ways: by comparison with three-dimensional field solver predictions and by contrast with their own measurements, and also previously published measurements.
Journal ArticleDOI
Design of Planar Rectangular Microelectronic Inductors
TL;DR: In this paper, the authors derived inductance equations for planar thin- or thick-film coils, comparing equations that include negative mutual inductance with those that do not, and presented a computer program developed for calculating inductances for both square and rectangular geometries, the variables considered being track width, space between tracks, and number of turns.
Journal ArticleDOI
Analytical Solutions to Eddy-Current Probe-Coil Problems
C. V. Dodd,W. E. Deeds +1 more
TL;DR: In this paper, the axially symmetric eddy-current problems are solved in two configurations of wide applicability. But the solutions are in the form of integrals of first-order Bessel functions giving the vector potential, from which other electromagnetic quantities of interest can be obtained.
Journal ArticleDOI
Analysis of eddy-current losses over conductive substrates with applications to monolithic inductors and transformers
Ali M. Niknejad,Robert G. Meyer +1 more
TL;DR: In this paper, a closed-form integral representation for the eddy-current losses over a conductive substrate is presented, which is applicable to monolithic inductors and transformers, especially when such structures are realized over an epitaxial CMOS substrate.