Parameters Consideration in Designing a Magnetorheological Damper

2013 ◽  
Vol 543 ◽  
pp. 487-490 ◽  
Author(s):  
Izyan Iryani Mohd Yazid ◽  
Saiful Amri Mazlan ◽  
Hairi Zamzuri ◽  
M.J. Mughni ◽  
S. Chuprat

This paper presents a simulation study of electromagnetic circuit design for a mixed mode Magnetorheological (MR) damper. The magnetic field generated by electromagnetic circuit of the MR damper was simulated using Finite Element Method Magnetics (FEMM) software package. All aspects of geometry parameters were considered and adjusted efficiently in order to obtain the best MR damper performance. Eventually, six different parameters approach were proposed; the selection of materials, the polarity of coils, the diameter of piston, piston rod and core, the shear and squeeze gaps clearance, the piston pole length and the thickness of housing.

2014 ◽  
Vol 660 ◽  
pp. 763-767 ◽  
Author(s):  
Khairunnisa Hairuddin ◽  
Saiful Amri Mazlan ◽  
Ubaidillah ◽  
Hairi Zamzuri ◽  
Norazman Mohamad Nor

Magnetorheological elastomer (MRE) is a controllable smart material that demonstrates changes in rheological properties depending on the magnetic field strength. This paper presents thedevelopment of a new concept of MRE isolator in terms of design and magnetic simulation. All features of geometry parameters were considered and altered expeditiously in order to provide ample and uniform magnetic field. Finite Element Method Magnetics (FEMM) was used to design the electromagnetic circuit to generate magnetic fluxes penetrate through the MRE. The study, eventually, leads to the conclusion of different design parameters approach; selection of materials, diameter of the shaft, shape of MRE, length of shaft and thickness of housing.


2020 ◽  
Vol 322 ◽  
pp. 01049
Author(s):  
Michal Kubík ◽  
Filip Jeniš ◽  
Igor Hašlík

The magnetorheological (MR) damper uses magnetorheological fluid which, when subjected to magnetic stimuli, generates an increase of damping forces. A significant problem of these dampers is their poor failsafe ability due to power supply interruption. In the case of faults, the damper remains in a low damping state, which is dangerous. This problem can be solved by accommodating a permanent magnet in the magnetic circuit of the damper. However, the magnetic circuit dynamic of this type of damper has rarely been studied. The main aim of this paper is to introduce the magnetic circuit dynamics of the magnetorheological damper/control valve with a permanent magnet. Firstly, the design of the magnetorheological valve with NdFe42 permanent magnet in the magnetic circuit is introduced. The response time of the magnetic field on the unit step of the control signal was calculated by transient magnetic simulation in Ansys Electronics software. The response time of the magnetic field was simulated in the range of 1.2 to 5 ms depending on the electric current magnitude and orientation. The presented MR damper was manufactured and tested. The experiments prove that the permanent magnet significantly affects the dynamics of the magnetic circuit.


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.


2013 ◽  
Vol 284-287 ◽  
pp. 3586-3590 ◽  
Author(s):  
Chia Pao Chang ◽  
Ying Hsiang Lin ◽  
Yu Cheng Chen

Magnetorheological fluid (MR fluid) has been widely used in the industrial fields, especially in the machinery, automobile, national defense and construction industries. Most of the researches of the Magnetorheological Damper only utilized device to examine the effects of different levels of voltage, amplitude and frequency on energy reduction. They find a combination of the number of circles of wire, damping tubes, enameled wire sleeves for liquid of MR damper controlled to increase the damping force. This study uses different ways to solve the problem. We think outside the box and apply the concepts and technology of systematic innovation method to improve the structure of the MR damper for increasing the effectiveness. This study uses the contradiction matrix, 39 engineering parameters, and 40 inventive and innovative principles to identify the areas of improvement to address the exist problems. Regarding the decrease of the magnetic field acting force due to increase of the moving distance and the effect on the magnetorheological damper efficiency. Finally, we propose an improved design of the MR Damper.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Xiaolong Yang ◽  
Guohong Wang ◽  
Ruibo Zhang

The stepped magnetofluid seal is an effective method for improving the pressure ability of ordinary magnetofluid seals (OMS) with large clearance. At present, the research on stepped magnetofluid seal with less than 0.4 mm small clearance has not been carried out yet. The equivalent magnetic circuit design of converging stepped magnetofluid seal (CSMS) with small clearance has been carried out and verified by magnetic field finite element method based on the CSMS theory and magnetic circuit theory. The effects of the width of the axial seal position, the height of the radial seal position, the number of the pole tooth in the axial seal position, and the number of the pole tooth in the radial seal position on the theoretical pressure ability of the CSMS are investigated by numerical simulation. The calculation results are analyzed and discussed. The results show that the magnetic flux leakage at the junction of the permanent magnet and pole piece causes the higher pressure ability of the CSMS structure designed by the equivalent magnetic circuit method than that calculated by the magnetic field finite element method. When the width of the axial seal position is greater than the height of the radial seal position and the number of pole teeth in the axial seal position is less than the number of pole teeth in the radial seal position, the CSMS has the best effect. Compared with OMS with small clearance, CSMS has greater advantages.


2011 ◽  
Vol 197-198 ◽  
pp. 314-317 ◽  
Author(s):  
Fei Fei Xing ◽  
De Cai Li ◽  
Wen Ming Yang ◽  
Xiao Long Yang

Based on the theoretical model, magnetic field distribution of rectangular teeth, two-sides dilated shape and one-side dilated shape teeth structure with common other conditions were calculated using finite element method when the sealing gap was 0.1mm and 0.12mm. The comparison of their results with the same sealing gap showed that rectangular teeth structure had the highest magnetic leakage. Moreover, the magnetic field distribution of sealing structures with rectangular stages on both the shaft and pole pieces under the same design and sealing gap were also calculated using the same method, whose result was compared with rectangular stages on pole pieces only. The comparison showed that the former did not have higher pressure capability obviously but led to higher magnetic leakage.


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):  
Q. Ouyang ◽  
J. Wang ◽  
J. J. Zheng ◽  
X. J. Wang ◽  
Y. Xi

Magnetorheological (MR) fluids contain suspensions that exhibit a rapid, reversible and tunable transition from a free-flowing state to a semi-solid state upon the application of an external magnetic field. This behavior has attracted significant attention in the development of dampers, shock absorption system, military and defence system and safety devices in aerospace engineering. However, many of the issues pertaining to MR damper behavior in impact and shock applications are relatively unknown. This study provides an experimental analysis and simulation analysis by using COMSOL multyphysics of MR dampers when they are subjected to impact and shock loading. To this end, a novel MR damper with a four-stage piston and independent input currents is designed and analyzed. In this paper, two-dimension symmetrical Computational Fluid Dynamics (CFDs) simulation for the laminar flow of an incompressible MR fluid in the annular gap in the presence of a varying magnetic field. The purpose of this research is to study the couple effect of electromagnetic field and the fluid flow field and magnitude of damping force in a macroscopic view. The governing differential equations describing the magnetic field and fluid flow in the annular gap are solved numerically by COMSOL Multiphysics. Through the electromagnetic analysis and flow field analysis, the coupling effect of the magnetic field between the coil and the multiphysics coupling effect of novel MR was be found. For the each coil has an independent power supply, so it can provide a wider range damping force by combining the electromagnetic field of coils.


Author(s):  
Jarier Wannous ◽  
Peter Horváth

The paper offers a few activities for high school students which use the magnetometer of a smartphone to measure the value of magnetic fields. The first part of the paper deals with finding the magnetometer of the used smartphone. Following is the first selection of activities which are focused on discovering the equation for measuring the magnetic field of coil with a negligible length, while the second selection of activities use the discovered equation to measure the permeability of vacuum and finally to measure the magnetic field of the earth. Sample results of the experiments are given, showing the accuracy and effectiveness of the conducted experiments. The activities offer teachers a novel way for teaching the equation for calculating the magnetic field of a coil, as well as measuring the permeability of vacuum in a classroom environment.


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