Stray field due to eddy currents on a cylinder with azimuthal cuts: A comparative analysis of the cut shape effect

The work concerns the assessment of the possibility of identifying changes in hardness of carburized and induction hardened layers using the eddy current method. The tests were carried out on three sets of samples, made of AMS 6414 steel, with different layer thickness, subjected to induction hardening and tempering in a wide temperature range, to obtain differences in layer hardness for each set. The samples of each set, with the layers with a hardness in the range of 760–920 HV, were subject to testes using eddy currents which consisted in the assessment of phase angle changes obtained as a result of the lift – off effect. Standard hardness measurements on the surfaces of the hardened layers were also carried out, and microhardness profiles were made on the cross-sections of the samples. The results of hardness measurements were subject to comparative analysis with the results of non-destructive tests and on this basis it was possible to identify changes in the hardness of layers, based on the results of non-destructive tests.

Download Full-text

Mathematical Model of the Process of Pallet Movement Along the Magnetic Type Centrifugal Brake Roller

MATEC Web of Conferences ◽

10.1051/matecconf/202134603009 ◽

2021 ◽

Vol 346 ◽

pp. 03009

Author(s):

Ildar Sharifullin ◽

Andrey Nosko ◽

Yevgeniy Safronov

Keyword(s):

Magnetic Field ◽

Mathematical Model ◽

Comparative Analysis ◽

External Magnetic Field ◽

Electromagnetic Induction ◽

Eddy Currents ◽

Disc Brake ◽

Safe Operation ◽

Magnetic Type ◽

The Mathematical Model

One of the main elements of safe operation of gravity flow racks used in pallet racks is a brake roller. The most promising design is a centrifugal brake roller of magnetic (eddy current) type. The principle of operation of such rollers is based on the laws of electromagnetic induction and involves the deceleration of a conductor moving in a magnetic field, due to the interaction of eddy currents (or Foucault currents) arising in the volume of the conductor, with an external magnetic field. The mathematical model of the process of pallet movement along a centrifugal brake roller of magnetic type is developed in the article. The equation of the speed of movement of the pallet along the centrifugal brake roller of magnetic type is obtained. Comparative analysis of the speed of movement of a pallet along centrifugal and disc brake rollers of magnetic type is carried out.

Download Full-text

Simulations and Measurements of Eddy Current Magnetic Signatures

Zeszyty Naukowe Akademii Marynarki Wojennej ◽

10.2478/sjpna-2018-0028 ◽

2018 ◽

Vol 215 (4) ◽

pp. 77-102

Author(s):

Paweł Polański ◽

Franciszek Szarkowski

Keyword(s):

Magnetic Field ◽

Eddy Current ◽

Eddy Currents ◽

Rate Of Change ◽

Scale Model ◽

Stray Field ◽

Physical Scale ◽

Magnetic Signature ◽

Magnetic Signatures ◽

Current Magnetic Field

Abstract Eddy current magnetic signature is, together with magnetization of ferromagnetic hull, mechanisms and devices on board, corrosion related and stray field sources one of the main sources of ship’s magnetic signature. Due to roll, pitch and yaw of the ship in external magnetic field, eddy currents are induced in conducting materials on board ship, mainly in conducting hull. Flow of those currents is a source of magnetic field around a ship. Principal eddy current component is related to roll movement as it depends on rate of change of external field which is the highest for roll. Induced currents have both in-phase and quadrature components. Magnitude of the eddy current magnetic field can have significant effect on total magnetic field signature after degaussing for ships such as mine sweepers and mine hunters. Paper presents calculations and simulations as well as measurements of model and physical scale model made of low magnetic steel performed in Maritime Technology Center. Contribution of eddy current magnetic field in total field in low roll frequencies has been estimated.

Download Full-text

Stray Field of a Pulse Septum Induced by Eddy Currents

IEEE Transactions on Applied Superconductivity ◽

10.1109/tasc.2004.829691 ◽

2004 ◽

Vol 14 (2) ◽

pp. 441-444 ◽

Cited By ~ 1

Author(s):

Y. Shoji ◽

K. Kumagai

Keyword(s):

Eddy Currents ◽

Stray Field

Download Full-text

Comparative Analysis of Three Algorithms for Two-Channel Common Frequency Sinewave Parameter Estimation: Ellipse Fit, Seven Parameter Sine Fit and Spectral Sinc Fit

Metrology and Measurement Systems ◽

10.2478/v10178-010-0022-8 ◽

2010 ◽

Vol 17 (2) ◽

pp. 255-270 ◽

Cited By ~ 8

Author(s):

Pedro Ramos ◽

Fernando Janeiro ◽

Tomáš Radil

Keyword(s):

Parameter Estimation ◽

Comparative Analysis ◽

Eddy Currents ◽

Radio Receiver ◽

Comparison Analysis ◽

Laser Anemometry ◽

Signal Parameters ◽

Sine Signal ◽

The Time Domain ◽

Fitting In

Comparative Analysis of Three Algorithms for Two-Channel Common Frequency Sinewave Parameter Estimation: Ellipse Fit, Seven Parameter Sine Fit and Spectral Sinc FitIn this paper, a comparison analysis of three different algorithms for the estimation of sine signal parameters in two-channel common frequency situations is presented. The relevance of this situation is clearly understood in multiple applications where the algorithms have been applied. They include impedance measurements, eddy currents testing, laser anemometry and radio receiver testing for example. The three algorithms belong to different categories because they are based on different approaches. The ellipse fit algorithm is a parametric fit based on the XY plot of the samples of both signals. The seven parameter sine fit algorithm is a least-squares algorithm based on the time domain fitting of a single tone sinewave model to the acquired samples. The spectral sinc fit performs a fitting in the frequency domain of the exact model of an acquired sinewave on the acquired spectrum. Multiple simulation situations and real measurements are included in the comparison to demonstrate the weaknesses and strong points of each algorithm.

Download Full-text