Восстановление топографии поверхностных дефектов ферромагнетиков при нормальном намагничивающем поле

2021 ◽  
pp. 35-41
Author(s):  
Ю.Л. Гобов ◽  
С.Э. Попов

A technique for reconstructing the topography of defects in ferromagnetic materials in a normal magnetizing field is considered. It is shown that with such a magnetization, the surface of a soft magnetic ferromagnetic material is an equipotential surface. An approximation is proposed that makes it possible to obtain its topography from the results of measuring the three components of the magnetic field at a small distance from the defect. The reconstruction accuracy was estimated from the results of calculating the field from the defect by the finite element method and reconstructing the topography of the defect using the proposed approximation.

2011 ◽  
Vol 24 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Ivan Yatchev ◽  
Krastio Hinov ◽  
Iosko Balabozov ◽  
Kristina Krasteva

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.


2009 ◽  
Vol 154 ◽  
pp. 175-179 ◽  
Author(s):  
Yutaka Sakurai ◽  
Ryo Nakajima ◽  
Hiroko Nakamura

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.


Author(s):  
S. Hosseinzadeh ◽  
Kh. Hosseinzadeh ◽  
A. Hasibi ◽  
D.D. Ganji

In this paper, the flow of non-Newtonian blood fluid with nanoparticles inside a vessel with a porous wall in presence of a magnetic field have been investigated. This study aimed to investigate various parameters such as magnetic field and porosity on velocity, temperature, and concentration profiles. In this research, three different models (Vogel, Reynolds and Constant) for viscosity have been used as an innovation. The governing equations are solved by Akbari-Ganji's Method (AGM) analytical method and the Finite Element Method (FEM) is used to better represent the phenomena in the vessel. The results show that increasing the Gr number, porosity and negative pressure increase the blood velocity and increasing the magnetic field intensity decrease the blood velocity.


Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3185 ◽  
Author(s):  
José Monzón-Verona ◽  
Pablo González-Domínguez ◽  
Santiago García-Alonso

In this work, we have obtained a new constitutive matrix to calculate the induced Lorentz electric current of in a conductive disk in movement within a magnetic field using the cell method in 3D. This disk and a permanent magnet act as a magnetic brake. The results obtained are compared with those obtained with the finite element method (FEM) using the computer applications Getdp and femm. The error observed is less than 0.1173%. Likewise, a second verification has been made in the laboratory using Hall sensors to measure the magnetic field in the proximity of the magnetic brake.


2013 ◽  
Vol 416-417 ◽  
pp. 264-269
Author(s):  
Pei Long Wang ◽  
Xiao Zhuo Xu ◽  
Bao Yu Du ◽  
Hai Chao Feng ◽  
Xu Dong Wang ◽  
...  

In this paper, two novel topological structures of sliding transformer with ferromagnetic core applied in the Contactless Electrical Power Transmission (CEPT) system used for the ropeless elevator driven by moving-coil type Permanent Magnet Synchronous Linear Motor (PMLSM) have been proposed, and the magnetic field distribution is calculated and analyzed by the finite element method (FEM). According to the analysis results of the traditional E-E topology sliding transformer, much higher coupling coefficients of sliding transformers with proposed topologies have been obtained. Then, based on the magnetic distribution and the circuit model of system, the compensation capacitances have been calculated considering supply frequency and load conditions. Finally, the load characteristic of the system with compensation is also obtained by FEM.


2005 ◽  
Vol 2 (2) ◽  
pp. 181-188
Author(s):  
Marian Greconici ◽  
Constantin Blaj ◽  
Barbu Nicoară

The magnetic field produced by a rotor with alternating magnetic poles in a magnetic fluid hydrostatic bearing is numerically evaluated. There has been used a 3D program based on the finite element method (3D-FEM).


Author(s):  
Igors Stroganovs ◽  
Andrejs Zviedris

Basic Statements of Research and Magnetic Field of Axial Excitation Inductor GeneratorIn this work the main features of axial excitation inductor generators are described. Mathematical simulation of a magnetic field is realized by using the finite element method. The objective of this work is to elucidate how single elements shape, geometric dimensions and magnetic saturation of magnetic system affect the main characteristics of the field (magnetic induction, magnetic flux linkage). The main directions of a magnetic system optimization are specified.


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