Simulation Research on the Magnetic Field of the Positioning Permanent Magnet for MEMS inside Human Body Based on Ansoft

2014 ◽  
Vol 596 ◽  
pp. 67-71
Author(s):  
Xiu Quan Liu ◽  
Yan Hong Li
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Magnetic Dipole ◽  
Human Body ◽  
Magnetic Induction ◽  
Dipole Model ◽  
Magnetization Direction ◽  
Simulation Research ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field

the magnetic dipole model of the cylindrical permanent magnet was introduced. Then, based on Ansoft software, the simulation model of the cylindrical permanent magnet was established, and the influence of some parameters, such as the height, radius and magnetization direction on the magnetic induction intensity ,were studied; at the same time, under these two models the calculation was compared, the result shows the the magnetic dipole model is applied on condition that distance is nine times greater than the cylindrical permanent magnet size.

Electromagnetic Nondestructive Testing Model and Surface Magnetic Field Analysis for Circumferential Cracks on Metal Rod

2019 ◽  
Vol 2 (4) ◽  
Author(s):  
Feng Jiang ◽  
Shulin Liu ◽  
Shaojie Xin ◽  
Hongli Zhang
Keyword(s):  
Magnetic Field ◽  
Analytical Model ◽  
Magnetic Induction ◽  
Crack Depth ◽  
Field Analysis ◽  
Surface Magnetic Field ◽  
Circumferential Crack ◽  
Inner Surface ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field

Abstract In this paper, an analytical model for a metal rod with a coating layer is proposed to evaluate circumferential crack from the signals of the surface magnetic field. In the proposed model, magnetic vector equations for four regions of space were built, and series expressions of the magnetic field were proposed by the truncated region eigenfunction method. The calculation results can show the three-dimensional distribution of axial and radial magnetic induction intensities on the surface of a metal rod clearly. In addition, the analytical model is verified by using comsol finite element simulation, which also demonstrates that induced eddy currents on the inner surface of the metal rod with cracks appear to be propelled toward the inner layer of the metal rod and the presence of a circumferential crack directly causes a decrease in the induced eddy current on the inner surface of the rod. The results calculated from the analytical model indicated that the model is capable of providing an accurate variation in the magnetic field due to circumferential cracks at different depths. The analytical results showed that the radial magnetic induction intensity increases by 0.16 × 10−3 T, while the axial magnetic induction intensity decreases by 0.3 × 10−3 T as the crack depth increases from 0 to 3 mm.

Temperature suppression of metal panel in electromagnetic field

Circuit World ◽  
2020 ◽  
Vol 46 (4) ◽  
pp. 317-324
Author(s):  
Guochao Zheng ◽  
Fuli Wang ◽  
Baiping Yan ◽  
Runting Cheng
Keyword(s):  
Permanent Magnet ◽  
Magnetic Induction ◽  
Permanent Magnets ◽  
Magnetic Field Intensity ◽  
Metal Plate ◽  
Content Type ◽  
Magnetic Induction Intensity ◽  
Metal Panels ◽  
The Magnetic Field ◽  
Field Intensity Distribution

Purpose The purpose of this study is to suppress the temperature rise of high voltage wall bushing metal plate. Design/methodology/approach First, the authors built a model of a traditional metal plate and got the magnetic field intensity distribution by FEA tools. Optimized according to the magnetic field intensity distribution, the authors slot the traditional metal plate and embed permanent magnets in the slot. Finally, the authors got the temperature distribution diagrams of the above three cases at different current levels by FEA tools. Findings Slotted metal plate is beneficial to suppress magnetic induction intensity, but the improvement of the magnetic induction intensity uniformity is not obvious. The method of embedding a permanent magnet in a slotted metal plate can optimize the magnitude and uniformity of the magnetic induction intensity in the metal plate. The larger the current passing through the metal plate, the better the temperature suppression effect of the slotted metal plate and the slotted metal plate embedded in the permanent magnet. Originality/value The effect of structural factors, slotting plate and setting permanent magnets on slots on the temperature of supporting plate is studied. The paper proposes two methods, slotting metal panels and embedding permanent magnet metal panels, to solve the problems of eddy current loss and high calorific value of the panel, which is of great significance to the safety of the grid equipment.

Development of Numerical Analysis Software for the NDE by Using Dipole Model

2007 ◽  
Vol 353-358 ◽  
pp. 2383-2386
Author(s):  
Jin Yi Lee ◽  
Jong Woo Jun ◽  
Ji Seong Hwang ◽  
Se Hoon Lee
Keyword(s):  
Magnetic Field ◽  
Numerical Analysis ◽  
Field Distribution ◽  
Electrical Signal ◽  
Dipole Model ◽  
Magnetic Field Distribution ◽  
Analysis Software ◽  
Magnetization Direction ◽  
Lift Off ◽  
The Magnetic Field

The magnetic field distribution around a crack can be calculated more easily and quickly by using a dipole model than finite element method (FEM). This paper reports the development of numerical analysis software that uses an improved dipole model to analyze the magnetic field around cracks. The preprocessor in this software includes the crack formation software, which can distribute the magnetic charge per unit area, m, on the crack section area. Also the lift-off, measurement area and sensor interval, and magnetization direction can be considered in the preprocessor. Also, the postprocessor presents functions, such as the natural magnetic field distribution and ∂B/∂x, ∂B/∂y, as results. Also, the physical characteristics of the magnetic optical sensor and the Hall sensor are included in the postprocessor, and the magnetic field distribution can be changed to optical intensity and electrical signal distribution. The experiment results, which are obtained by using the magnetic camera on the crack, are compared with analysis results obtained by using the dipole model analysis software.

The Magnetic Field Analysis of Dual-Coil Self-Sensing Actuator

2011 ◽  
Vol 181-182 ◽  
pp. 183-188 ◽  
Author(s):  
Cheng Wu Lin ◽  
Fang Dong ◽  
Hao Zheng ◽  
Hua Yan
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Reference Value ◽  
Element Model ◽  
Field Analysis ◽  
Magnetic Field Analysis ◽  
Intensity Changes ◽  
Working Principle ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field

This paper introduced working principle of dual-coil self-sensing actuator based on magnetically controlled shape memory alloy (MSMA). The ANSYS software was used to establish the finite element model of MSMA dual-coil self-sensing actuator. Edge element method was adopted to analyze the MSMA dual-coil self-sensing actuator's 3-D static magnetic field under the influence of different excitation voltages. The analysis obtained MSMA and silicon steel sheet distribution of magnetic induction intensity and the magnetic field intensity, has further confirmed the reliability of MSMA dual-coil self-sensing actuator, and has given the MSMA length relations along with the magnetic induction intensity changes. The results show that magnetic field analysis has certain reference value to the MSMA practical application.

Simulation Study on Magnetic Field Characteristics of High Magnetic Field Intensity Permanent Magnet Magnetic Filter

2010 ◽  
Vol 97-101 ◽  
pp. 2622-2627
Author(s):  
Hong Guang Jiao ◽  
Peng Liu ◽  
Zhan Xu Tie
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Field Intensity ◽  
Magnetic Field Intensity ◽  
Magnetic Circuit ◽  
Magnetic Filter ◽  
Circuit Structure ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field ◽  
Outside Diameter

To solve the conflict between separation space and magnetic field intensity, an original magnetic circuit structure system of permanent magnet magnetic filter is designed by utilizing multi-dimensional magnet extrusion technologies, with multi-block NdFeB magnets of different structures and magnetization directions. The inside diameter of the ring magnets and ring soft iron is taken as separating space. To inspect the distribution of the magnetic field characteristics of magnetic circuit system, mathematical model is established, and the designed magnetic circuit system is simulated, taking advantage of the electromagnetic software Magnet. The simulation results show that a larger separating space and higher background magnetic density can be achieved simultaneously by means of the organic magnetic circuit system design, when the thickness of ring soft iron is 4mm and the diameter ratio (outside diameter to the diameter) of ring magnets is 10/3. The highest magnetic induction intensity of 29.2 mm separating space is 1.5T, which provides the basis for permanent magnet magnetic circuit design.

Analysis of the Planar Magnetic Field of Linear Permanent Magnet Halbach Array

2011 ◽  
Vol 66-68 ◽  
pp. 1336-1341
Author(s):  
Xiao Zhang ◽  
Yun Gang Li ◽  
Hu Cheng ◽  
Heng Kun Liu
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Element Analysis ◽  
Magnetization Direction ◽  
Halbach Array ◽  
The Finite Element Analysis ◽  
Analytical Algorithm ◽  
Analytical Expressions ◽  
The Magnetic Field ◽  
A Current

In this paper, the analytical solution to the planar magnetic field of a linear permanent magnet Halbach array is researched on. First, the magnetic field of a current surface is derived from the magnetic field produced by the molecular current of the permanent magnet. The magnetic fields of pieces of permanent magnet with vertical and diagonal magnetization direction are both solved by combining the magnetic field of current surfaces with different directions. Then the planar magnetic field of the entire linear permanent magnet Halbach array is obtained by calculating the vector addition of the magnetic field of all the permanent magnet cubes using Denavit-Hartenberg (D-H) transform technique, which yields the closed-form analytical expressions. The analytical algorithm proposed in this paper can be utilized to design and optimize the Halbach array, which in result can greatly simplify the calculation and expedite the progress. The effectiveness of the proposed method is evaluated by the finite element analysis software Maxwell.

scholarly journals Analysis of the Influence of Ferromagnetic Material on the Output Characteristics of Halbach Array Energy-Harvesting Structure

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1541
Author(s):  
Xiangyong Zhang ◽  
Haipeng Liu ◽  
Yunli He ◽  
Tingrui Peng ◽  
Bin Su ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Magnetic Induction ◽  
Ferromagnetic Material ◽  
Magnetic Medium ◽  
Halbach Array ◽  
Harvesting Efficiency ◽  
Energy Harvesting Efficiency ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field

Due to the particular arrangement of permanent magnets, a Halbach array has an significant effect of magnetism and magnetic self-shielding. It can stretch the magnetic lines on one side of the magnetic field to obtain an ideal sinusoidal unilateral magnetic field. It has a wide application range in the field of energy harvesting. In practical applications, magnetic induction intensity of each point in magnetic field is not only related to the induced current and conductor but also related to the permeability of the medium (also known as a magnetic medium) in the magnetic field. Permeability is the physical quantity that represents the magnetism of the magnetic medium, which indicates the resistance of magnetic flux or the ability of magnetic lines to be connected in the magnetic field after coil flows through current in space or in the core space. When the permeability is much greater than one, it is a ferromagnetic material. Adding a ferromagnetic material in a magnetic field can increase the magnetic induction intensity B. Iron sheet is a good magnetic material, and it is easy to magnetize to generate an additional magnetic field to strengthen the original magnetic field, and it is easy to obtain at low cost. In this paper, in order to explore the influence of ferromagnetic material on the magnetic field and energy harvesting efficiency of the Halbach array energy harvesting structure, iron sheets are installed on the periphery of the Halbach array rotor. Iron sheet has excellent magnetic permeability. Through simulation, angle between iron sheet and Halbach array, radian size of iron sheet itself and distance between iron sheet and Halbach array can all have different effects on the magnetic field of the Halbach array. It shows that adding iron sheets as a magnetic medium could indeed change the magnetic field distribution of the Halbach array and increase energy harvesting efficiency. In this paper, a Halbach array can be used to provide electrical power for passive wireless low-power devices.

scholarly journals Polarization of Pulsars

1971 ◽  
Vol 46 ◽  
pp. 195-199
Author(s):  
Alan T. Moffet
Keyword(s):  
Magnetic Field ◽  
Magnetic Dipole ◽  
Faraday Rotation ◽  
Linear Polarization ◽  
Polarization Characteristic ◽  
Position Angle ◽  
Dipole Model ◽  
Yield Values ◽  
Dispersion Measures ◽  
The Magnetic Field

A survey is given of the polarization properties of pulsars. Many pulsars, although showing pulse-to-pulse variations in polarization, have a stable mean polarization characteristic. Several pulsars like 0833-45 show changes in the position angle of linear polarization across the pulse which can be interpreted as due to the changing direction of the magnetic field as envisaged in the oblique magnetic dipole model of pulsars. Faraday rotation measurements when taken with dispersion measures yield values for the interstellar magnetic field of several microgauss.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

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