Experimental and Theoretical Study on Magnetoelastic Buckling of a Ferromagnetic Cantilevered Beam-Plate

1978 ◽  
Vol 45 (2) ◽  
pp. 355-360 ◽  
Author(s):  
K. Miya ◽  
K. Hara ◽  
K. Someya
Keyword(s):  
Magnetic Field ◽  
Theoretical Study ◽  
Critical Value ◽  
The Finite Element Method ◽  
Wide Face ◽  
Field Distortion ◽  
Cantilevered Beam ◽  
Magnetically Soft Material ◽  
Experimental Values ◽  
The Magnetic Field

When a cantilever of magnetically soft material is inserted with its wide face normal to a uniform magnetic field and the magnetic field is increased to a critical value the cantilever will buckle. The experimental magnetoelastic buckling fields and the theoretical ones differ by a factor of two. A magnetic field distortion near an edge of the specimen is here evaluated based on the finite-element method and the results are applied to the experimental results so as to explain the discrepancy between the experiment and the theory. The corrected experimental values are within 15 percent of the theoretical values. The effect of demagnetization on the buckling field is here demonstrated as well as the effect of specimen dimensions.

Magnetoelastic Buckling of Thin Magnetically Soft Plates in Cylindrical Mode

1974 ◽  
Vol 41 (1) ◽  
pp. 145-150 ◽  
Author(s):  
J. M. Dalrymple ◽  
M. O. Peach ◽  
G. L. Viegelahn
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Rectangular Plate ◽  
Empirical Formula ◽  
Uniform Magnetic Field ◽  
Critical Value ◽  
Elliptical Plate ◽  
Wide Face ◽  
Magnetically Soft Material ◽  
Plate Width

When a plate of magnetically soft material is supported with its wide face normal to a uniform magnetic field, it will buckle when the field reaches a critical value. It is shown theoretically that the critical buckling field for a “half-restrained” rectangular plate should be 0.833 of that for a half-restrained elliptical plate of identical dimensions and material. Limited experimental data support this conclusion. The effect of plate width upon critical buckling field is investigated experimentally and an empirical formula is presented which fits the data reasonably well.

scholarly journals Static force characteristics of electromagnetic actuators for Braille screen

2011 ◽  
Vol 24 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Ivan Yatchev ◽  
Krastio Hinov ◽  
Iosko Balabozov ◽  
Kristina Krasteva
Keyword(s):  
Magnetic Field ◽  
Finite Element Method ◽  
Finite Element ◽  
Permanent Magnet ◽  
Static Force ◽  
The Finite Element Method ◽  
Electromagnetic Actuators ◽  
Minimum Force ◽  
The Magnetic Field ◽  
Force Characteristics

Several constructions of electromagnetic actuators with moving permanent magnet for Braille screen are studied. All they are formed from a basic one that consists of two coils, core and moving permanent magnet. The finite element method is used for modeling of the magnetic field and for obtaining the electromagnetic force acting on the mover. The static force-stroke characteristics are obtained for four different constructions of the actuator. The constructions with ferromagnetic disc between the coils ensure greater force than the ones without disc and can reach the required minimum force.

scholarly journals A theoretical study of a possible model of paramagnetic alums at low temperatures

1940 ◽  
Vol 176 (965) ◽  
pp. 203-213 ◽  
Keyword(s):  
Magnetic Field ◽  
Low Temperatures ◽  
Theoretical Study ◽  
Spontaneous Magnetization ◽  
Critical Value ◽  
Transition Curve ◽  
Thin Specimen ◽  
First Order ◽  
Freely Suspended ◽  
Line Of Critical Points

An attempt is made to examine theoretically the properties of paramagnetic alums at low temperatures. The model taken is a lattice of freely suspended magnets, all interactions except purely magnetic being neglected. Even with this simplification it is impossible at present to make rigorous calculations of the partition function, either on classical or quantum lines. A simple model is proposed, which is really a generalization of the Bragg - Williams theory enabling one to take account of the effect of a magnetic field. The few configurations whose energies are known are used to fix arbitrary constants in the expression assumed for the energy. The theory predicts that the state of lowest energy is either a spontaneously magnetized, state for a long thin specimen, or a state in which alternate rows of magnets point in opposite directions for a sphere, spontaneous magnetization appearing in an ellipsoid with an eccentricity greater than a certain critical value. The transition curve bounding the region in which the antiparallel state is stable consists partly of a line of Curie points corresponding to transitions of the second, order, passing smoothly into a line of critical points corresponding to a transition of the first order. The effect of shape on the magnetic properties of the specimen seems to be experimentally verified, but the rough nature of the theory prevents it being more than qualitative.

Magnetic Field Analysis for Magnetron Sputtering Apparatus for Accurate Composition Control

2009 ◽  
Vol 154 ◽  
pp. 175-179 ◽  
Author(s):  
Yutaka Sakurai ◽  
Ryo Nakajima ◽  
Hiroko Nakamura
Keyword(s):  
Magnetic Field ◽  
Finite Element Method ◽  
Magnetron Sputtering ◽  
Field Analysis ◽  
The Finite Element Method ◽  
Film Composition ◽  
Composite Target ◽  
Composition Control ◽  
Magnetic Field Analysis ◽  
The Magnetic Field

Authors use magnetron sputtering technique for controlling the film composition by modifying the magnetic field with an external solenoid in addition to the magnetic field with a permanent magnet on back of composite target. It is necessary to understand the contribution of the solenoid quantitatively for the effective application of this technique. The magnetic field changes by the solenoid current on the target were calculated by the finite element method (FEM), and compared with the film composition. As the solenoid current increases, magnetic tunnel region on the target (correspond with the well sputtered region by the confined plasma) moves to the centre of the target. The behaviour corresponds with the actually formed film composition. The calculated results also give an information to design the composite target and the correction value for using the already eroded target.

Article

1998 ◽  
Vol 76 (7) ◽  
pp. 507-513
Author(s):  
O Bolina ◽  
J R Parreira
Keyword(s):  
Magnetic Field ◽  
Transverse Magnetic Field ◽  
Ground State ◽  
Linear Chain ◽  
Critical Value ◽  
Transverse Magnetic ◽  
The State ◽  
Xy Model ◽  
The Magnetic Field

We show that the ground state of the xy model (ferromagnetic orantiferromagnetic) in a transverse magnetic field h --- for any spin value, in any dimension --- is the state with all spins aligned antiparallel to the field when h is greater than some critical value hc. In particular, for the spin-1/2 linear chain, we study the behavior of correlations as functions of the magnetic field. PACS Nos.: 75.10Jm and 64.60.Cm

scholarly journals Критический ток в длинном джозефсоновском контакте во внешнем магнитном поле при слабом пиннинге

2022 ◽  
Vol 92 (3) ◽  
pp. 414
Author(s):  
М.А. Зеликман
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Critical Current ◽  
Critical Value ◽  
Transport Current ◽  
Entire Length ◽  
Gibbs Potential ◽  
Potential Reduction ◽  
The Magnetic Field ◽  
Josephson Contact

The analysis of possible current distributions when passing current through a periodically modulated long Josephson contact located in an external magnetic field is carried out. An approach based on the analysis of continuous configuration modification proceeding in the direction of Gibbs potential reduction is used for the calculation. The case when the pinning parameter is less than the critical value is considered. It is shown that at any value of the external magnetic field, there is a critical value of the transport current, when exceeded, the situation ceases to be stationary, as a result of which energy passes into radiation and heat, i.e. currents cease to be persistent. The value of the critical current is determined by the value of the magnetic field at which the vortices begin to fill the entire length of the contact. With an increase in the external magnetic field, the critical value of the current decreases.

scholarly journals New Superconductivity and Theoretical Study on a New Phenomenon of Energy Source with Assistance of Initial Experiments

2018 ◽  
Author(s):  
Shinichi Ishiguri
Keyword(s):  
Magnetic Field ◽  
Energy Source ◽  
Electrostatic Field ◽  
Theoretical Study ◽  
Depletion Layer ◽  
Field Energy ◽  
Magnetic Field Energy ◽  
New Type ◽  
The Magnetic Field ◽  
A Current

We previously reported new superconductivity produced by an electrostatic field and a diffusion current in a semiconductor without refrigeration. In particular, the superconductivity was investigated theoretically and confirmed experimentally. Here, we determine that the derived superconducting quantum state can be reproduced in a capacitor. When circuits are formed with this new-type capacitor and diodes, a magnetic field is applied to the diodes’ depletion layer. The depletion layer is biased because of the conversion from the magnetic-field energy to electric-field energy, resulting in the diodes’ spontaneously emitting a current. Thus, the new-type capacitor is charged using no other energy source. This new phenomenon is described theoretically with assistance of initial experiments.

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