scholarly journals Factors affecting errors due to 2-D approximate analysis of 3-D magnetic fields with eddy currents (rotating machines)

1991 ◽  
Vol 27 (6) ◽  
pp. 5223-5225 ◽  
Author(s):  
N. Takahashi ◽  
T. Nakata ◽  
K. Fujiwara ◽  
T. Nishimura
Keyword(s):  
Magnetic Fields ◽  
Eddy Currents ◽  
Approximate Analysis ◽  
Rotating Machines ◽  
Factors Affecting

Hidden Crack Detection with GMR Sensing of Magnetic Fields from Eddy Currents

2007 ◽  
Author(s):  
Ray T. Ko ◽  
Shamachary Sathish ◽  
Jeremy S. Knopp ◽  
Mark P. Blodgett
Keyword(s):  
Magnetic Fields ◽  
Crack Detection ◽  
Eddy Currents

scholarly journals Magnetization Loss in HTS Coated Conductor Exposed to Harmonic External Magnetic Fields for Superconducting Rotating Machines

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Mohammad Yazdani-Asrami ◽  
Wenjuan Song ◽  
Min Zhang ◽  
Weijia Yuan ◽  
Xiaoze Pei
Keyword(s):  
Magnetic Fields ◽  
Coated Conductor ◽  
Rotating Machines ◽  
Magnetization Loss

scholarly journals Eddy Current Transducer with Rotating Permanent Magnets to Test Planar Conducting Plates

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1408 ◽  
Author(s):  
Tomasz Chady ◽  
Jacek Grochowalski
Keyword(s):  
Magnetic Fields ◽  
Eddy Current ◽  
Permanent Magnets ◽  
Eddy Currents ◽  
Nonuniform Distribution ◽  
Current Transducer ◽  
Different Depths ◽  
Hall Sensors ◽  
Eddy Current Transducer

In this paper, we present an eddy current transducer with rotating permanent magnets for the inspection of planar conducting plates. The transducer consists of a rotating head with permanent magnets, which is used to generate variable magnetic fields and thus induce eddy currents in the tested material. Two Hall sensors connected in a differential manner are used to detect a nonuniform distribution of eddy currents induced in a specimen containing a defect. To prove the usability of the transducer, a number of experiments were conducted on thick aluminum samples containing notches at different depths. Selected results of the achieved measurements are presented.

scholarly journals Investigation of welds by the method of the magneto-optical eddy current flaw detection

2018 ◽  
Vol 185 ◽  
pp. 02014 ◽  
Author(s):  
Nazar Lugovskoy ◽  
Vladimir Berzhansky ◽  
Dmitry Filippov ◽  
Anatoliy Prokopov ◽  
Alexandr Shuyskyy
Keyword(s):  
Mathematical Modeling ◽  
Magnetic Fields ◽  
Eddy Current ◽  
Eddy Currents ◽  
Flaw Detection ◽  
Current Method ◽  
Epitaxial Films ◽  
Eddy Current Method ◽  
Ferrite Garnet ◽  
Conducting Materials

The paper deals with the magneto-optical eddy current method of flaw detection of conducting materials, in which epitaxial films of ferrite garnet are used as sensors. In particular, the possibilities of visualization of welded seams in magnetic and non-magnetic samples, as well as the defectoscopy of the seams themselves, are considered. The second part of the work is devoted to mathematical modeling of the distribution of the magnetic fields of eddy currents near similar defects.

scholarly journals The loss of energy in metal plates of finite thickness, due to eddy currents produced by alternating magnetic fields

1926 ◽  
Vol 111 (759) ◽  
pp. 604-614 ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Eddy Currents ◽  
Finite Thickness ◽  
Metal Plate ◽  
The Self ◽  
Alternating Magnetic Field ◽  
Metal Plates ◽  
Alternating Magnetic Fields

The induction of eddy currents in metal plates which are subjected to alternating magnetic fields has been discussed by Clerk-Maxwell, J. J. Thomson and many others. When an alternating magnetic field is produced normal to the surface of a metal plate, eddy currents are induced at the surface of the plate, which gradually penetrate its interior, the current dying away as it penetrates more deeply into the metal. The diffusion of the currents into the plate depends upon the self-induction and resistance of the paths along which they flow, and can be calculated by the same kind of formula as is used for determining the conduction of heat through a metal slab.

Transient magnetic field formulation for solid source conductors

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1539-1545
Author(s):  
Georg Wimmer ◽  
Sebastian Lange
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Vector Potential ◽  
Numerical Scheme ◽  
Eddy Currents ◽  
Magnetic Vector Potential ◽  
Magnetic Vector ◽  
Time Step ◽  
Azimuthal Component ◽  
Transient Magnetic Fields

The formulation for the azimuthal component of the magnetic vector potential for axisymmetric magnetostatic applications is well known. However for transient magnetic fields with solid source conductors and eddy currents the formulation has to be revised. A variable transformation is introduced to remove the singularity from the numerical scheme. The numerical error cannot accumulate and is put instead to the postprocessing at every time step.

UNIQUE DETERMINATION OF CONDUCTIVITY, SUSCEPTIBILITY, SIZE, AND DEPTH IN MULTIFREQUENCY ELECTROMAGNETIC EXPLORATION

Geophysics ◽  
1959 ◽  
Vol 24 (3) ◽  
pp. 531-546 ◽  
Author(s):  
Stanley H. Ward
Keyword(s):  
Magnetic Fields ◽  
Eddy Currents ◽  
Intermediate Frequency ◽  
Unique Determination ◽  
Frequency Range ◽  
Lower Range ◽  
Ore Body ◽  
Eddy Current Density ◽  
Magnetic Sphere

The response of a conductive, magnetic sphere in a uniform, alternating magnetic field is a function of the conductivity, permeability, and radius of the sphere and of the frequency of the alternations. Over one range of frequencies, eddy‐current density in any given sphere and secondary magnetic fields of the sphere are relatively constant and high. Over a much lower range of frequencies eddy currents are negligible, but the secondary magnetic fields may be of large constant amplitude but of polarity reversed to that of the higher frequency range. At some intermediate frequency the secondary magnetic fields will be entirely quadrature with respect to the inducing field. Utilization of this peculiar frequency dependence and of the geometry of the secondary magnetic fields permits unique determination of the conductivity, permeability, radius, and depth to the center of a buried sphere. The procedure for obtaining these variables is described in this article. As an added feature, it is shown that by completing a gravity survey as well as an electromagnetic survey over a dense, magnetic, conductive spherical ore body, it is possible to determine the above variables, plus density, uniquely. Precise identification of the material of the sphere is seen as a possible result of the application of this technique.

Sign in / Sign up

Export Citation Format

Share Document