Magnetic Field Analysis of the Actuator in a Semi-Active Vibration Control of the Beam with MR Fluid

In this study the analysis of the magnetic field distribution of an electromagnet is presented. This electromagnet is used as an actuator in a semi-active vibration control of the three-layer beam with MR fluid. Two separate numerical methods are used for the purpose of calculating the magnetic field distribution. The first method is based on the Finite Element Method and implemented using ANSYS software. The second, simplified one is based on the assumption that the electromagnet can be substituted by a simple magnetic circuit divided into separate paths, with each sub-path defined by the value of reluctance of the corresponding electromagnet part. The comparison of the results from both methods with the ones obtained from an experiment is also presented and analyzed in the paper.

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Magnetic Circuit Simulation for Magnetorheological (MR) Fluids Testing Rig in Squeeze Mode

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.123-125.991 ◽

2010 ◽

Vol 123-125 ◽

pp. 991-994 ◽

Cited By ~ 7

Author(s):

Izwan Ismail ◽

Saiful Amri Mazlan ◽

Abdul Ghani Olabi

Keyword(s):

Magnetic Field ◽

Magnetic Flux ◽

Field Distribution ◽

Circuit Simulation ◽

Magnetic Field Distribution ◽

Mr Fluid ◽

Flux Lines ◽

Mr Fluids ◽

Magnetic Flux Lines ◽

The Magnetic Field

In this study, a testing rig in squeeze was designed and developed with the ability to conduct various tests especially for quasi-static squeezing at different values of magnetic field strength. Finite Element Method Magnetics (FEMM) was utilized to simulate the magnetic field distribution and magnetic flux lines generation from electromagnetic coil to the testing rig. Tests were conducted with two types of MR fluid. MRF-132DG was used to obtain the behaviour of MR fluid, while synthesized epoxy-based MR fluid was used for investigating the magnetic field distribution with regards to particle chains arrangement. Simulation results of the rig design showed that the magnetic flux density was well distributed across the tested materials. Magnetic flux lines were aligned with force direction to perform squeeze tests. Preliminary experimental results showed that stress-strain pattern of MR fluids were in agreement with previous results. The epoxy-based MR samples produced excellent metallographic samples for carbonyl iron particles distributions and particle chain structures investigation.

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Frequency Shaped Semi-Active Control for Magnetorheological Fluid-Based Vibration Control Systems

Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation and Control of Adaptive Systems; Integrated System Design and Implementation ◽

10.1115/smasis2013-3268 ◽

2013 ◽

Author(s):

Young-Tai Choi ◽

Norman M. Wereley ◽

Gregory J. Hiemenz

Keyword(s):

Vibration Control ◽

Control Systems ◽

Active Control ◽

Control Algorithm ◽

Active Vibration Control ◽

Control Algorithms ◽

Model Parameters ◽

Mr Fluid ◽

Control Current ◽

Active Vibration

Novel semi-active vibration controllers are developed in this study for magnetorheological (MR) fluid-based vibration control systems, including: (1) a band-pass frequency shaped semi-active control algorithm, (2) a narrow-band frequency shaped semi-active control algorithm. These semi-active vibration control algorithms designed without resorting to the implementation of an active vibration control algorithms upon which is superposed the energy dissipation constraint. These new Frequency Shaped Semi-active Control (FSSC) algorithms require neither an accurate damper (or actuator) model, nor system identification of damper model parameters for determining control current input. In the design procedure for the FSSC algorithms, the semi-active MR damper is not treated as an active force producing actuator, but rather is treated in the design process as a semi-active dissipative device. The control signal from the FSSC algorithms is a control current, and not a control force as is typically done for active controllers. In this study, two FSSC algorithms are formulated and performance of each is assessed via simulation. Performance of the FSSC vibration controllers is evaluated using a single-degree-of-freedom (DOF) MR fluid-based engine mount system. To better understand the control characteristics and advantages of the two FSSC algorithms, the vibration mitigation performance of a semi-active skyhook control algorithm, which is the classical semi-active controller used in base excitation problems, is compared to the two FSSC algorithms.

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COMPARISON OF CARDIAC MAGNETIC FIELD DISTRIBUTIONS DURING DEPOLARIZATION AND REPOLARIZATION

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127403008971 ◽

2003 ◽

Vol 13 (12) ◽

pp. 3783-3789 ◽

Cited By ~ 4

Author(s):

F. E. SMITH ◽

P. LANGLEY ◽

L. TRAHMS ◽

U. STEINHOFF ◽

J. P. BOURKE ◽

...

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Magnetic Field Strength ◽

Field Distribution ◽

Normal Subjects ◽

The Body ◽

Magnetic Field Distribution ◽

T Wave ◽

High Magnetic Field Strength ◽

The Magnetic Field

Multichannel magnetocardiography measures the magnetic field distribution of the human heart noninvasively from many sites over the body surface. Multichannel magnetocardiogram (MCG) analysis enables regional temporal differences in the distribution of cardiac magnetic field strength during depolarization and repolarization to be identified, allowing estimation of the global and local inhomogeneity of the cardiac activation process. The aim of this study was to compare the spatial distribution of cardiac magnetic field strength during ventricular depolarization and repolarization in both normal subjects and patients with cardiac abnormalities, obtaining amplitude measurements by magnetocardiography. MCGs were recorded at 49 sites over the heart from three normal subjects and two patients with inverted T-wave conditions. The magnetic field intensity during depolarization and repolarization was measured automatically for each channel and displayed spatially as contour maps. A Pearson correlation was used to determine the spatial relationship between the variables. For normal subjects, magnetic field strength maps during depolarization (R-wave) showed two asymmetric regions of magnetic field strength with a high positive value in the lower half of the chest and a high negative value above this. The regions of high R-wave amplitude corresponded spatially to concentrated asymmetric regions of high magnetic field strength during repolarization (T-wave). Pearson-r correlation coefficients of 0.7 (p<0.01), 0.8 (p<0.01) and 0.9 (p<0.01) were obtained from this analysis for the three normal subjects. A negative correlation coefficient of -0.7 (p<0.01) was obtained for one of the subjects with inverted T-wave abnormalities, suggesting similar but inverted magnetic field and current distributions to normal subjects. Even with the high correlation values in these four subjects, the MCG was able to identify differences in the distribution of magnetic field strength, with a shift in the T-wave relative to the R-wave. The measurement of cardiac magnetic field distribution during depolarization and repolarization of normal subjects and patients with clinical abnormalities should enable the improvement of theoretical models for the explanation of the cardiac depolarization and repolarization processes.

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Measurement of the Magnetic Field Distribution in Railguns Using CMR-B-Scalar Sensors

Acta Physica Polonica A ◽

10.12693/aphyspola.115.1125 ◽

2009 ◽

Vol 115 (6) ◽

pp. 1125-1127 ◽

Cited By ~ 15

Author(s):

O. Liebfried ◽

M. Schneider ◽

M.J. Loeffler ◽

S. Balevičius ◽

N. Žurauskienė ◽

...

Keyword(s):

Magnetic Field ◽

Field Distribution ◽

Magnetic Field Distribution ◽

The Magnetic Field

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Quantitative imaging of the magnetic field distribution in an artificial spin ice studied by off-axis electron holography

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2021.168535 ◽

2021 ◽

pp. 168535

Author(s):

Teresa Weßels ◽

András Kovács ◽

Sebastian Gliga ◽

Simone Finizio ◽

Jan Caron ◽

...

Keyword(s):

Magnetic Field ◽

Field Distribution ◽

Quantitative Imaging ◽

Magnetic Field Distribution ◽

Electron Holography ◽

Spin Ice ◽

Artificial Spin Ice ◽

The Magnetic Field

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Numerical simulation of induction heating thick-walled tubes

MATEC Web of Conferences ◽

10.1051/matecconf/201816802004 ◽

2018 ◽

Vol 168 ◽

pp. 02004

Author(s):

Richard Lenhard ◽

Milan Malcho ◽

Katarína Kaduchová

Keyword(s):

Magnetic Field ◽

Numerical Simulation ◽

Field Distribution ◽

Induction Heating ◽

Electromagnetic Induction ◽

Magnetic Field Distribution ◽

The Magnetic Field ◽

Heated Material ◽

Ansys Workbench

In the paper is shown the connection of two toolboxes in an Ansys Workbench solution for induction heating. In Ansys Workbench, Maxwell electromagnetism programs and Fluent have been linked. In Maxwell, a simulation of electromagnetic induction was performed, where data on the magnetic field distribution in the heated material was obtained and then transformed into the Fluent program in which the induction heating simulation was performed.

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Uticaj armirano betonskog stuba na raspodelu magnetskog polja mešovitog voda

Energija, Ekonomija, Ekologija ◽

10.46793/eee20-1-2.058g ◽

2020 ◽

Vol 22 (1-2) ◽

pp. 58-64

Author(s):

Teodora Gavrilov ◽

◽

Karolina Kasaš-Lažetić ◽

Kristian Haška ◽

Miroslav Prša

Keyword(s):

Magnetic Field ◽

Field Distribution ◽

Magnetic Field Distribution ◽

Magnetic Flux Density ◽

Reinforcing Bars ◽

Magnitude Distribution ◽

Calculation Results ◽

Mixed Power ◽

The Impact ◽

The Magnetic Field

In this paper, the analysis of magnetic field distribution of overhead mixed power line (20 kV/0.4 kV) supported by reinforced concrete towers, named MNL-12 is presented. The impact of ferromagnetic, conductive parts of the pylons (reinforcing bars, billets and cross arm beams) on magnetic field distribution is investigated. The numerical calculations were performed in COMSOL Multiphysics program package on simplified 2D model. The main goal of the calculations was to examine the impact of currents induced in ferromagnetic conductive parts on magnetic field produced by currents in the power system’s conductors. The calculation results are presented graphically, as the diagrams of the magnetic flux density magnitude distribution in the tower plan, normal to the system’s axe. The calculation results demonstrated that the magnetic field of induced currents decreases the magnetic field produced by the currents of overhead power system.

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Investigation on the Improvement of Surface Quality by the Magnetic Plate-Assisted Magnetic Abrasive Finishing Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1018.111 ◽

2021 ◽

Vol 1018 ◽

pp. 111-116

Author(s):

Yan Hua Zou ◽

Hui Jun Xie

Keyword(s):

Magnetic Field ◽

Surface Quality ◽

Field Distribution ◽

Magnetic Field Distribution ◽

Magnetic Flux Density ◽

Magnetic Pole ◽

Magnetic Abrasive Finishing ◽

Abrasive Finishing ◽

Glass Lens ◽

The Magnetic Field

The traditional magnetic abrasive finishing (MAF) process, the magnetic flux density at the bottom of the magnetic pole is unevenly distributed, resulting in poor uniformity of the finished surface. Therefore, it is proposed to improve the surface quality by attaching a magnetic plate at the bottom of the workpiece to improve the magnetic field distribution. It is confirmed by simulation that the magnetic field distribution at the bottom of the magnetic pole is effectively improved after the magnetic plate is attached. It is proved through experiments that the magnetic plate-assisted MAF process can obtain a smoother surface. The experimental results show that the surface roughness of the glass lens improves from 246 nm Ra to 3 nm Ra through the magnetic plate-assisted MAF process within 45min.

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