Internal Organizational Measurement for Control of Magnetorheological Fluid Properties

2006 ◽  
Vol 129 (4) ◽  
pp. 423-428 ◽  
Author(s):  
John R. Lloyd ◽  
Miquel O. Hayesmichel ◽  
Clark J. Radcliffe
Keyword(s):  
Magnetic Field ◽  
Physical Properties ◽  
High Sensitivity ◽  
Time Varying ◽  
Measurable Effect ◽  
Mr Fluid ◽  
Fluid State ◽  
Mr Fluids ◽  
Fluid Properties ◽  
Field Excitation

Magnetorheological (MR) fluids change their physical properties when subjected to a magnetic field. As this change occurs, the specific values of the physical properties are a function of the fluid’s time-varying organization state. This results in a nonlinear, hysteretic, time-varying fluid property response to direct magnetic field excitation. Permeability, resistivity and permittivity changes of MR fluid were investigated and their suitability to indicate the organizational state of the fluid, and thus other transport properties, was determined. High sensitivity of permittivity and resistivity to particle organization and applied field was studied experimentally. The measurable effect of these material properties can be used to implement an MR fluid state sensor.

Design and Performance of a MR Torque Transfer Device

Aerospace ◽  
2005 ◽  
Author(s):  
Kevin Molyet ◽  
Constantin Ciocanel ◽  
Hideki Yamamoto ◽  
Nagi Naganathan
Keyword(s):  
Magnetic Field ◽  
Element Analysis ◽  
Mr Fluid ◽  
Mr Fluids ◽  
Active Portion ◽  
Fluid Properties ◽  
Predicted Values ◽  
And Performance ◽  
And Behavior ◽  
Transfer Device

Magnetorheological (MR) fluids possess the unique ability to undergo dramatic and nearly completely reversible changes in their rheological properties under the application of a magnetic field. These controllable fluids can serve as quiet, rapid interfaces between electronic controls and mechanical systems. One area of application is to use these fluids in torque transfer devices, such as clutches and brakes. After determining MR fluid properties and behavior using a rheometer, a parallel disk type MR clutch was successfully developed, which utilized a stationary electromagnetic coil. Finite element analysis was used to design the coil and clutch assembly in order to maximize the magnetic field generated within the MR fluid. The resulting magnetic field was uniform over the active portion of the clutch, easily controllable by adjusting the current passing through the coil, and provided a large range of field strength values. The experimentally measured output torque was generally in good agreement with predicted values. This work will detail the design considerations and methodology used to develop this clutch, which can be extended to the design of other MR devices.

Geometric Analysis in an MR Fan Clutch

2011 ◽  
Vol 239-242 ◽  
pp. 1731-1734 ◽  
Author(s):  
Jian Zuo Ma ◽  
Guo Chao Wang ◽  
Dong Zuo
Keyword(s):  
Angular Velocity ◽  
Yield Strength ◽  
Geometric Analysis ◽  
Control Torque ◽  
Load Torque ◽  
Mr Fluid ◽  
Mr Fluids ◽  
Torque Transmission ◽  
Fluid Properties ◽  
Transmission Ability

A magnetorheological (MR) fan clutch is introduced. Based on Herschel-Bulkley model, the equation of transmission torque developed by MR fluids is derived to compute the torque transmission ability in the MR fan clutch. The necessary gap and the need of MR fluid volume between two parallel circular discs of the clutch are carried out. The results indicate that, the transmission torque of the MR fan clutch developed rapidly depend on the yield strength of MR fluid. The necessary gap and the volume for the MR fan clutch can be obtained based on MR fluid properties, the desired control torque ratio, the angular velocity and load torque of the clutch.

Performance Simulation on a Magnetorheological Valve Module Using Three Different Commercial Magnetorheological Fluid

2015 ◽  
Vol 1123 ◽  
pp. 35-41
Author(s):  
Burhanuddin Ichwan ◽  
Saiful Amri Mazlan ◽  
Fitrian Imaduddin ◽  
Ubaidillah ◽  
Hairi Zamzuri
Keyword(s):  
Pressure Drop ◽  
Simulation Studies ◽  
Fluid Type ◽  
Mr Fluid ◽  
Performance Simulation ◽  
Mr Fluids ◽  
Fluid Properties ◽  
Magnetorheological Effect ◽  
Radial Gap ◽  
Magnetorheological Valve

Simulation studies on a new concept of modular Magnetorheological (MR) valve using annular-radial gap combination are discussed in this paper. This study predicts and compares the performance of MR valve module with three different commercial kind MR fluids namely the MRF-122EG, MRF-132DG, and MRF140CG. Magnetorheological effect in various types of MR fluid is analyzed using finite element method (FEM) software in term of simulation magnetic field density within the valve module. The approximated functions of permeability and field dependent yield stress for each kind of MR fluid are derived and presented in this paper as a prerequisite for simulation works. The result has shown that the highest pressure drop rating is reached by applying an MR fluid type MRF140CG, for another kind has shown smallest of pressure drop rating because of the ability to produce the achievable pressure drop highly depends on MR fluid properties.

MAGNETORHEOLOGICAL FLUIDS AND THEIR PROPERTIES

2005 ◽  
Vol 19 (01n03) ◽  
pp. 593-596 ◽  
Author(s):  
J. M. HE ◽  
J. HUANG
Keyword(s):  
Magnetic Field ◽  
Yield Strength ◽  
Rheological Properties ◽  
Yield Stress ◽  
Applied Magnetic Field ◽  
Magnetorheological Fluids ◽  
Mr Fluid ◽  
Variable Yield ◽  
Mr Fluids

Magnetorheological (MR) fluids are materials that respond to an applied magnetic field with a change in their rheological properties. Upon application of a magnetic field, MR fluids have a variable yield strength. Altering the strength of the applied magnetic field will control the yield stress of these fluids. In this paper, the method for measuring the yield stress of MR fluids is proposed. The curves between the yield stress of the MR fluid and the applied magnetic field are obtained from the experiment. The result indicates that with the increase of the applied magnetic field the yield stress of the MR fluids goes up rapidly.

Development and Verification of Viscoelasticity Measurement System of MR Fluids in Magnetic Field

2012 ◽  
Vol 721 ◽  
pp. 114-119 ◽  
Author(s):  
Yuta Enokizono ◽  
Takashi Todaka ◽  
Masato Enokizono
Keyword(s):  
Magnetic Field ◽  
Measurement System ◽  
High Speed ◽  
Uniform Magnetic Field ◽  
Precise Measurement ◽  
Mr Fluid ◽  
Knowledge Based ◽  
Mr Fluids ◽  
The Magnetic Field ◽  
Speed Response

MR (Magnetic Rheological) fluid is a kind of functional fluid, which can be hardened by impressing magnetic flux. MR fluid has the high speed response to the external magnetic field and a big yield stress in comparison with the ferrofluid. In recent years, various devices utilizing MR fluid have been developed. Such developments are enabled with knowledge based on measured viscoelastic properties of MR fluid. However, precise measurement to obtain effect of the magnetic field on viscoelasticity is very difficult. The difficulty exists in generating a uniform magnetic field and evaluating the effective magnetic field. Accurate measurements become possible by solving these problems. In this paper, we propose a new magneto-viscoelasticity measurement system of MR fluid, which can generate a uniform magnetic field.

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

2010 ◽  
Vol 123-125 ◽  
pp. 991-994 ◽  
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.

Shear and Squeeze Rheometry of Magnetorheological Fluids

2011 ◽  
Vol 305 ◽  
pp. 344-347 ◽  
Author(s):  
Hong Yun Wang ◽  
Hui Qiang Zheng
Keyword(s):  
Magnetic Field ◽  
Yield Stress ◽  
Electrical Current ◽  
Test System ◽  
Compression Stress ◽  
Shear Yield Stress ◽  
Mr Fluid ◽  
Mr Fluids ◽  
Shear Yield ◽  
The Magnetic Field

The mechanical properties of a magnetorheological (MR) fluid in shearing, compression and shearing after compression have been studied in the magnetic field which is generated by a coil carrying different magnitudes of DC electrical current on a self-constructed test system. The relations of compression stress versus compression strain, yield stress versus compression stress were studied under different magnetic fields. The compressing tests showed that the MR fluid is very stiff at small compressive strains lower than 0.13. The shear yield stress of MR fluids after compression was much stronger than that of uncompressed MR fluids under the same magnetic field. The enhanced shear yield stress of MR fluids can be utilized to design the MR clutch and brake for new structure and will make MR fluids technology attractive for many applications.

Dynamic Characterization of Non-Homogeneous Magnetorheological Fluids Based Multi-Layer Beam

2011 ◽  
Vol 110-116 ◽  
pp. 105-112 ◽  
Author(s):  
Vasudevan Rajamohan ◽  
Manoharan Ramamoorthy
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Mr Fluid ◽  
Various Boundary Conditions ◽  
Mr Fluids ◽  
Magneto Rheological ◽  
Loss Factors

The vibration properties of multi-layer beam structure comprising axially non-homogeneous magneto-rheological (MR) fluids layer are investigated. The governing equations of a non-homogeneous MR fluids multi-layered beam are formulated using finite element method and Ritz formulation. The validity of the proposed finite element formulations is demonstrated by comparing the results with those obtained from the Ritz formulation. The properties of different configurations of a non-homogeneous MR-fluid beam are evaluated to investigate the influences of the location of the different MR-fluids for various boundary conditions. The properties in terms of natural frequencies and loss factors corresponding to various modes are evaluated under different magnetic field intensities. The effect of location of the fluid treatment on deflection mode shapes is also investigated. The results suggest that the natural frequencies and loss factors of the non-homogeneous MR fluid beams are strongly influenced not only by the intensity of the applied magnetic field, but also by the location of the MR fluids. It is also concluded that the application of non-homogeneous MR fluids could also alter the deflection pattern of the beam, particularly the location of the peak deflection.

scholarly journals Enhanced Magnetorheological Performance of Carbonyl Iron Suspension Added With Barium Ferrite Nanoparticle

2021 ◽  
Vol 8 ◽  
Author(s):  
Hyo Seon Jang ◽  
Qi Lu ◽  
Hyoung Jin Choi
Keyword(s):  
Magnetic Field ◽  
Carbonyl Iron ◽  
Barium Ferrite ◽  
Flow Behavior ◽  
Vibrating Sample Magnetometry ◽  
Mr Fluid ◽  
Mr Fluids ◽  
Ferrite Nanoparticle ◽  
The Magnetic Field ◽  
Mr Characteristics

Hard-magnetic barium ferrite (BF) nanoparticles with a hexagonal plate-like structure were used as an additive to a carbonyl iron (CI) microparticle-based magnetorheological (MR) fluid. The morphology of the pristine CI and CI/BF mixture particles was examined by scanning electron microscopy. The saturation magnetization and coercivity values of each particle were measured in the powder state by vibrating sample magnetometry. The MR characteristics of the CI/BF MR fluid measured using a rotation rheometer under a range of magnetic field strengths were compared with those of the CI-based MR fluid. The flow behavior of both MR fluids was fitted using a Herschel–Bulkley model, and their stress relaxation phenomenon was examined using the Schwarzl equation. The MR fluid with the BF additive showed higher dynamic and elastic yield stresses than the MR fluid without the BF additive as the magnetic field strength increased. Furthermore, the BF nanoparticles embedded in the space between the CI microparticles improved the dispersion stability and the MR performance of the MR fluid.

Mathematical Modelling of Magneto-Hydrodynamic Dampers With Time-Varying Fluid Properties

2005 ◽  
Author(s):  
Mario F. Letelier ◽  
Dennis A. Siginer ◽  
Jean-Paul Rouliez ◽  
Omar F. Corral
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Yield Stress ◽  
Time History ◽  
Field Variation ◽  
Time Varying ◽  
Viscosity Change ◽  
Flow Equations ◽  
Fluid Properties ◽  
Analytical Tools

The fluid dynamics of dampers is investigated for the case where the damping fluid flows through passages in which a magnetic field is applied. This is a specific case of a new and promising field of applications that has emerged through the design of devices that take advantage of some properties of the so-called electrorheological fluids and magnetorheological fluids (ERF and MRF). These fluids are created when a base fluid is seed with very small dielectric or iron particles, so that it reacts to electric or magnetic fields by developing some non-Newtonian characteristics, most prominently a yield stress, viscosity change, and also viscoelasticity. These fluid properties can be controlled through control of the electric or magnetic fields’ strength. In this paper, a typical damping load is modeled and related to the required flow of a MRF inside the damper. To this end the fluid is modeled as a Bingham fluid with time-varying yield-stress. The analysis here developed makes it possible to determine the magnetic field variation necessary in order to achieve a specific displacement of the damper’s piston. The flow equations are analytically solved for any time-history of the dimensionless fluid’s yield-stress. Main results are some simplified relationships that correlate damping load and magnetic field time-variations. These results aim at providing analytical tools that may facilitate dampers’ design.

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