Distribution of Magnetic Flux Density and Magnetic Force in EMR

2013 ◽  
Vol 652-654 ◽  
pp. 2248-2253
Author(s):  
Jiang Hua Deng ◽  
Chao Tang ◽  
Yan Ran Zhan ◽  
Xing Ying Jiang
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Force ◽  
Coupling Model ◽  
Energy Utilization ◽  
Magnetic Flux Density ◽  
The Finite Element Method ◽  
Field Coupling ◽  
Driver Plate ◽  
Electromagnetic Riveting

Distribution of magnetic flux density and magnetic force in electromagnetic riveting was investigated with the electromagnetic field coupling model established by the finite element method. The results show the radial magnetic flux density presents a sinusoidal exponential decaying form at a point and the maximum value of radial magnetic flux density lies in about half of the driver plate radius along the driver plate radius direction. The distribution of magnetic force is determined by that of magnetic flux density and the magnetic force is a body force, which weakens very quickly from the inside to the outside of the driver plate. In order to prevent penetration of magnetic field, the thickness of driver plate is an important parameter to increase the energy utilization ratio.

Effect of Electromagnetic Stirring during Solidification on the Morphological Evolution of Primary Solid Phase of Al Alloy

2006 ◽  
Vol 116-117 ◽  
pp. 665-668 ◽  
Author(s):  
Dock Young Lee ◽  
Suk Won Kang ◽  
Ki Bae Kim
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Force ◽  
Solid Phase ◽  
Morphological Evolution ◽  
Input Voltage ◽  
Input Current ◽  
Magnetic Flux Density ◽  
Al Alloy ◽  
Α Phase

In this study, in order to develop the cast product of Al alloy having a globular microstructure by using the elctromagnetic (EM) stirrer, which was specially designed and manufactured to induce a various fluid flow type of melt during solidification, a morphlogy and size of primary solid phase of the solidifying slurry was investigated with respect to EM stirring condition such as an induced magnetic flux density (MFD) and a frequency of input current. The magnetic flux density of EM stirrer was measured by using a gaussmeter and its distribution and magnetic force within Al melt was simulated in ANSYS program. The induced MFD was increased with decreasing a frequency of input current at the same input voltage due to the increased penetrating depth of magnetic field. But, the magnetic force related directly with a stirring strength of melt was increased with the frequency. Both a roundness and size of primary α phase of Al alloy was decreased with increasing a frequency of input current and MFD within the experimental range. Therefore, the primary α phase was refined and globularized at the higher frequency and MFD.

scholarly journals Application of the Taguchi method for finite element analysis of a shear-type magnetorheological fluid damper

2020 ◽  
Vol 12 (4) ◽  
pp. 168781401990039 ◽  
Author(s):  
Dyi-Cheng Chen ◽  
Li-Ren Chen
Keyword(s):  
Magnetic Flux ◽  
Taguchi Method ◽  
Flux Density ◽  
Magnetic Force ◽  
Optimal Parameter ◽  
Magnetorheological Fluid ◽  
Magnetic Flux Density ◽  
Cylinder Wall ◽  
Magnetorheological Fluid Damper ◽  
Fluid Damper

A magnetorheological fluid damper is a device in which a magnetorheological fluid is filled in a damper. In this device, the magnetic field is controlled by an external current (voltage) so that the magnetic force of a piston inside the damper changes like an electromagnet. The damping force of the damper is controlled by changing the magnetic force of the piston. With the increasing magnetic force of the piston, the viscosity of the magnetorheological fluid in the damper increases. The primary aim of this study was to maximize the magnetic flux density and identify the following influencing factors from the relevant literature: piston and outer tube materials, piston length, piston diameter, cylinder wall thickness, damper channel clearance, gap channel length, current, and magnetorheological fluid. A magnetic circuit analysis was performed using ANSYS Maxwell, and the optimal parameter combination was identified using the Taguchi method. The analysis of variance was used to examine the influence of various factors on quality characteristics. This study helps understand the relation between structure size, material, and magnetic flux density and contributes to future generations of magnetorheological fluid damper design analysis.

Numerical study of magnetic circuit response in magneto-rheological damper

2016 ◽  
Vol 14 (1) ◽  
pp. 196-210 ◽  
Author(s):  
Mohammad Sadak Ali Khan ◽  
A. Suresh ◽  
N. Seetha Ramaiah
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Yield Stress ◽  
Flux Density ◽  
Magnetic Force ◽  
Mr Damper ◽  
Magnetic Flux Density ◽  
Piston Velocity ◽  
Mr Fluid ◽  
Content Type

Purpose – The purpose of this paper is to evaluate the performance of the semi-active fluid damper. It is recognized that the performance of such a damper depends upon the magnetic and hydraulic circuit design. These dampers are generally used to control the vibrations in various applications in machine tools and robots. The present paper deals with the design of magneto-rheological (MR) damper. A finite element model is built to analyze and understand the performance of a 2D axi-symmetric MR damper. Various configurations of damper with modified piston ends are investigated. The input current to the coil and the piston velocity are varied to evaluate the resulting change in magnetic flux density (B), magnetic field (H), field dependent yield stress and magnetic force vectors. The simulation results of the various configurations of damper show that higher magnetic force is associated with plain piston ends. The performance of filleted piston ends is superior to that of other configurations for the same magnitude of coil current and piston velocity. Design/methodology/approach – The damper design is done based on the fact that mechanical energy required for yielding of MR fluid increases with increase in applied magnetic field intensity. In the presence of magnetic field, the MR fluid follows Bingham’s plastic flow model, given by the equation τ = η γ•+τ y (H) τ > τ y . The above equation is used to design a device which works on the basis of MR fluid. The total pressure drop in the damper is evaluated by summing the viscous component and yield stress component which is approximated as ΔP = 12ηQL/g3W + CτyL/g, where the value of the parameter, C ranges from a minimum of 2 (for ΔPτ ΔPη less than approximately 1) to a maximum of 3 (for ΔPτ/ΔPη greater than approximately 100). To calculate the change in pressure on either side of the piston within the cylinder, yield stress is required which is obtained from the graph of yield stress vs magnetic field intensity provided by Lord Corporation for MR fluid −132 DG. Findings – In this work, three different finite element models of MR damper piston are analyzed. The regression equations, contour plots and surface plots are obtained for different parameters. This study can be used as a reference for selecting the parameters for meeting different requirements. It is observed from the simulation of these models that the plain ends model gave optimum magnetic force and 2D flux lines with respect to damper input current. This is due to the fact that the plain ends model has more area when compared with that of other models. It is also observed that filleted ends model gave optimum magnetic flux density and yield stress. As there is reduced pole length in the filleted ends model, the MR fluid occupies vacant area, and hence results in increased flux density and yield shear stress. The filleted ends assist the formation of dense magnetic flux lines thereby increasing the flux density and yield stress. This implies that higher load can be carried by the filleted ends damper even with a smaller size. Originality/value – This work is carried out to manufacture different capacities of the dampers. This can be applied as vibration controls.

Magnetic Spring and Experimental Research on its Stiffness Properties

2013 ◽  
Vol 706-708 ◽  
pp. 1418-1422
Author(s):  
Xiao Mei Xu ◽  
Cai Min Zeng
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Force ◽  
Permanent Magnets ◽  
Air Gap ◽  
Magnetic Flux Density ◽  
Field Energy ◽  
Magnetic Spring ◽  
Stiffness Properties ◽  
Excitation Coil

Structure of one hybrid mono-directional magnetic spring was presented. Based on the experiment rig of magnetic spring the stiffness properties and its influencing factors were experimentally studied and analyzed. Research results show that the stiffness of the hybrid magnetic spring composed of the electromagnet and the permanent magnets is adjustable and controllable. As a whole the axial magnetic force of the magnetic spring increases non-linearly with the air gap between magnets decreasing, but within small air gap when there is considerable difference in magnetic flux density between the two magnets the axial magnetic force will decrease with the air gap decreasing, namely the magnetic spring behaves negative stiffness characteristics. The axial magnetic force is decided by the magnet with less magnetic field energy. And the adjusting range of axial magnetic force depends on the two magnets dimensions, their surface magnetic flux density and the magnetic saturation degree of the electromagnet. Furthermore, under same air gap the axial magnetic force of the magnetic spring increases linearly with the excitation coil voltage increasing.

scholarly journals The Innovative Design of Deep In Situ Pressure Retained Coring Based on Magnetic Field Trigger Controller

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Guikang Liu ◽  
Mingzhong Gao ◽  
Zhiwen Yang ◽  
Ling Chen ◽  
Maoquan Fu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Force ◽  
Magnetic Circuit ◽  
Minimum Condition ◽  
Magnetic Flux Density ◽  
Valve Seat ◽  
Deep Rock

Deep rock mass theory has not yet been completely established, which leads to a lack of theoretical guidance for deep resource development and poor continuity among engineering activities. The foundation of deep rock mechanics theory is to achieve the deep in situ rock fidelity coring (including the retaining of the pore pressure and temperature). To realize this, pressure-retaining coring technology is required. A self-triggered pressure-retaining controller based on magnetic control is proposed in this paper. The pressure-retaining controller realizes pressure-retaining coring in any direction by triggering the closure of the valve cover by a magnetic force, forming a magnetic seal. Fifteen combined magnetic circuit design schemes are proposed. The magnetic flux density norm distribution and magnetic force evolution law of different schemes are then quantitatively analyzed by the finite element method. The results show that a complex magnetization combination can weaken the nonlinear negative correlation between the magnetic force and distance. The optimal design of the valve seat magnetic circuit is Scheme 9, with the valve seat consisting of four shape identical tile magnets. Among the schemes, for Scheme 9, the magnetic flux density norm of the valve cover is the most concentrated. The maximum magnetic flux density norm is in the middle, and the magnetic force at 35 mm from the valve cover to the valve seat is 2.915 N. Scheme 9 satisfies the minimum condition of the mechanical model and verifies the feasibility of magnetic field triggering. This research can be used to gain a better understanding of deep Earth properties and provides technology for the improved design of deep in situ pressure-retaining coring devices.

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