Nonlinear vibration behavior of a carry current ferromagnetic beam plate under magnetic fields and thermal loads

2020 ◽  
Vol 26 (15-16) ◽  
pp. 1276-1285
Author(s):  
Elham Tahmasebi ◽  
Nariman Ashrafi Khorasani ◽  
Ali Imam
Keyword(s):  
Magnetic Field ◽  
Electric Current ◽  
Eddy Currents ◽  
Nonlinear Differential Equations ◽  
Vibrational Behavior ◽  
Thermal Fields ◽  
Ferromagnetic Plate ◽  
Soft Ferromagnetic ◽  
The Galerkin Method ◽  
The Magnetic Field

In order to study the magnetoelastic instability and natural frequency of a ferromagnetic plate under a magnetic field, different magnetic force models are considered. In the present study, considering more realistic assumptions, new equations for the study of the vibrational behavior of ferromagnetic beam plates carrying the electric current in the magnetic field are presented by employing the theory of Eringen and Maxwell relations. Conclusively, the effects of magnetic traction and thermal fields created by electric current and eddy currents are taken into account. The coupled nonlinear differential equations of the system are separated by the Galerkin method and solved numerically. The numerical results are compared with the results in the literature, and the effect of different parameters on the vibration characteristics of the soft ferromagnetic beam plate is investigated. The results show that the components of the force that are created by magnetic tractions, as well as the assumption of thermal couplings, can significantly change the vibrational behavior of the plates. Also, by increasing the intensity of the electric current and the magnetic field, the amplitude of the oscillations of the plate is increased and instability occurs for certain values of these parameters in the system.

scholarly journals The effect of simplifications of a numerical mesh on the results of electromagnetic analysis of the Nuclotron-type cable

2018 ◽  
Vol 177 ◽  
pp. 08004
Author(s):  
Łukasz Tomków
Keyword(s):  
Magnetic Field ◽  
Electric Current ◽  
Current Density ◽  
Electric Current Density ◽  
Electromagnetic Analysis ◽  
First Case ◽  
Single Region ◽  
The Magnetic Field

The model of a single Nuclotron-type cable is presented. The goal of this model is to assess the behaviour of the cable under different loads. Two meshes with different simplifications are applied. In the first case, the superconductor in the cable is modelled as single region. Second mesh considers individual strands of the cable. The significant differences between the distributions of the electric current density obtained with both models are observed. The magnetic field remains roughly similar.

scholarly journals The hall effect in liquid electrolytes

1913 ◽  
Vol 88 (606) ◽  
pp. 588-604 ◽  
Keyword(s):  
Magnetic Field ◽  
Hall Effect ◽  
Electric Current ◽  
Metal Plate ◽  
Satisfactory Explanation ◽  
Thermo Electric ◽  
Field Independent ◽  
Set Up ◽  
The Magnetic Field ◽  
Thin Metal Plate

The distortion of the lines of flow of an electric current in a thin metal plate by the action of a magnetic field was discovered in 1879. Hall attributed this to the action of the magnetic field on the molecular currents in the metal film, which were deflected to one side or the other and accompanied by a corresponding twist of the equipotential lines. This explanation did not pass without criticism, and another theory of the effect found by Hall was published in 1884. In that paper the author seeks to explain the effect by assuming a combination of certain mechanical strains and Peltier effects, a thermo-electric current being set up between the strained and the unstrained portions. The effect of such strain was to produce a reverse effect in some metals, and these were precisely the metals for which the Hall effect was found to reverse. Aluminium was the only exception. In other respects, however, as shown by Hall in a later paper, Bidwell's theory did not stand the test of experiment, and the results lend no support to his theory, while they are in complete accordance withe the explanation that the molecular currents are disturbed by the action of the magnetic field. On the electron theory of metallic conduction, the mechanism of the Hall effect is more obvious, but at present no satisfactory explanation of the reversal found in some metals is known. Further experiments have made it clear that there is a real deflection of the elementary currents, due to the application of the magnetic field, independent of any effect due to strain.

Electromagnetic damping of elastic waves: Experimental results

1968 ◽  
Vol 5 (4) ◽  
pp. 825-829 ◽  
Author(s):  
F. E. M. Lilley ◽  
C. M. Carmichael
Keyword(s):  
Magnetic Field ◽  
Elastic Wave ◽  
Applied Magnetic Field ◽  
Elastic Waves ◽  
Applied Field ◽  
Eddy Currents ◽  
Electrical Conductor ◽  
Electromagnetic Damping ◽  
The Waves ◽  
The Magnetic Field

The passage of an elastic wave causes straining and translation in the transmitting material. If a magnetic field is applied, and the medium is an electrical conductor, some of the energy of the wave is dissipated by the flow of electrical eddy currents. Usually the amount of energy lost is very small, but it may be greatly increased if the applied field is strongly non-uniform.Laboratory experiments are described which demonstrate this effect for standing elastic waves in a metal bar. The applied magnetic field changes from almost zero to its full strength over a distance which is short compared to the length of the standing wave. The result of this strong non-uniformity is that the energy lost due to the translation of the bar in the field greatly exceeds the energy lost due to the straining of the bar in the field.The dependence of the attenuation of the waves by the magnetic field is investigated for variation in frequency of vibration, bar thickness, and field gradient.

The equilibrium configuration of a slowly rotating mass of liquid in the presence of a poloidal magnetic field

1972 ◽  
Vol 55 (1) ◽  
pp. 105-112
Author(s):  
C. Sozou
Keyword(s):  
Magnetic Field ◽  
Electric Current ◽  
Equilibrium Configuration ◽  
Spherical Surface ◽  
Perturbation Expansion ◽  
Reverse Direction ◽  
Poloidal Magnetic Field ◽  
Inviscid Liquid ◽  
Axis Of Rotation ◽  
The Magnetic Field

The equilibrium configuration of a slowly rotating self-gravitating perfectly conducting inviscid liquid, in the presence of a small poloidal magnetic field, is considered for a case where the electric current is a simple function of the distance from the axis of rotation. Owing to the coupling of the magnetic field with the rotation the electric current may reverse direction. This could make the magnetic field zero on certain surfaces and impose restrictions on the parameters of the problem. A perturbation expansion of the nearly spherical surface of the liquid is constructed.

Fraction Solid Measurements on Solidifying Melt

2004 ◽  
Vol 126 (2) ◽  
pp. 193-197 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt ◽  
Sorin G. Teodorescu
Keyword(s):  
Magnetic Field ◽  
Aluminum Alloy ◽  
Indirect Method ◽  
Eddy Currents ◽  
Solid Phase ◽  
Molten Metals ◽  
Metal Sample ◽  
Fraction Solid ◽  
The Magnetic Field ◽  
Good Agreement

A new indirect method to measure fraction solid in molten metals is presented. The method is based on the phenomena that when a metal sample (solid or liquid) rotates in a magnetic field (or the magnetic field rotates around a stationary sample), circulating eddy currents are induced in the sample, which generate an opposing torque related to amount of solid phase in a solidifying melt between the liquidus and solidus temperatures. This new technique is applied for measuring fraction solid on commercial A319 aluminum alloy. The solidification curves obtained by the proposed method at different cooling rates are in good agreement with predictions made by the Scheil model.

scholarly journals Magnetic Field Generated during Electric Current-Assisted Sintering: From Health and Safety Issues to Lorentz Force Effects

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1653
Author(s):  
Huaijiu Deng ◽  
Jian Dong ◽  
Filippo Boi ◽  
Theo Saunders ◽  
Chunfeng Hu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electric Current ◽  
Lorentz Force ◽  
Health And Safety ◽  
Interparticle Contact ◽  
Safety Issues ◽  
Contact Points ◽  
The Magnetic Field ◽  
Health And Safety Issues

In the past decade, a renewed interest on electromagnetic processing of materials has motivated several investigations on the interaction between matter, electric and magnetic fields. These effects are primarily reconducted to the Joule heating and very little attention has been dedicated to the magnetic field contributions. The magnetic field generated during electric current-assisted sintering has not been widely investigated. Magnetism could have significant effects on sintering as it generates significant magnetic forces, resulting in inductive electrical loads and preferential heating induced by overlapping magnetic fields (i.e., proximity effect). This work summarizes the magnetic field effects in electric current-assisted processing; it focuses on health and safety issues associated with large currents (up to 0.4 MA); using FEM simulations, it computes the self-generated magnetic field during spark plasma sintering (SPS) to consolidate materials with variable magnetic permeability; and it quantifies the Lorentz force acting at interparticle contact points. The results encourage one to pay more attention to magnetic field-related effects in order to engineer and exploit their potentials.

Anisotropic Magnetoresistance of Stretched Sheets of Carbon Nanotubes

2012 ◽  
Vol 1407 ◽  
Author(s):  
Elena Cimpoiasu ◽  
David Lashmore ◽  
Brian White ◽  
George A. Levin
Keyword(s):  
Magnetic Field ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Nitric Acid ◽  
Electric Current ◽  
Anisotropic Magnetoresistance ◽  
Catalyst Nanoparticles ◽  
Positive Term ◽  
The Magnetic Field ◽  
Bulk Carbon

ABSTRACTWe performed magnetoresistance (MR) measurements on bulk carbon nanotube sheets that had been partially aligned by post-fabrication stretching. The magnetic field was applied under different orientations with respect to the direction of the stretch, while the electric current was either parallel or perpendicular to the direction of the stretch. We found that the fielddependence of the MR is composed of two terms, one positive and one negative. The magnitudes of both terms are largest when the field is parallel with the direction of the stretch. If the sheets are treated with nitric acid, the positive term is removed and the MR is smallest when the field is aligned with the magnetic field. We attribute these anisotropic features to magnetoelastic effects induced by the coupling between the magnetic catalyst nanoparticles, the magnetic field, and the network of nanotubes.

Fraction Solid Measurements on A319 Aluminum Alloy

2002 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt ◽  
Sorin G. Teodorescu
Keyword(s):  
Magnetic Field ◽  
Aluminum Alloy ◽  
Eddy Currents ◽  
Solid Phase ◽  
Molten Metals ◽  
Metal Sample ◽  
Fraction Solid ◽  
A New Technique ◽  
The Magnetic Field ◽  
Good Agreement

A new indirect method to measure fraction solid on molten metals is presented. The method is based on the phenomena that when a metal sample (solid or liquid) rotates in a magnetic field (or the magnetic field rotates around a stationary sample), circulating eddy currents are induced in the sample, which generate an opposing torque proportional to amount of solid phase that precipitates in a solidifying melt between the liquidus and solidus temperatures. A new technique is applied for measuring fraction solid on commercial A319 aluminum alloy. The solidification curves obtained by the proposed method at different cooling rates are in a good agreement with the predictions made by the Scheil model.

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