EFFECT OF MAGNETIC FIELD ON PROPERTIES OF MR FLUIDS

2005 ◽  
Vol 19 (01n03) ◽  
pp. 597-601 ◽  
Author(s):  
J. HUANG ◽  
J. Q. ZHANG ◽  
J. N. LIU
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Theoretical Model ◽  
Yield Stress ◽  
Applied Magnetic Field ◽  
Mr Fluids ◽  
Magnetic Chain ◽  
Viscoplastic Properties

The yield stress is one of the most important parameters that characterize viscoplastic properties of magnetorheological (MR) fluids. Based on the microstructure of magnetic-chain a theoretical model is developed to analyze the effect of the applied magnetic field on the yield stress. It has been shown that the values of the yield stress calculated by the model agree well with the experimental data.

Yield and Rheological Behaviors of Magnetorheological Fluids

2010 ◽  
Vol 97-101 ◽  
pp. 875-879
Author(s):  
Jian Min He ◽  
Jin Huang ◽  
Cheng Liu
Keyword(s):  
Magnetic Field ◽  
Yield Stress ◽  
Applied Magnetic Field ◽  
Applied Field ◽  
Shear Strain Rate ◽  
Bingham Model ◽  
Bingham Plastic ◽  
Rheological Behaviors ◽  
Mr Fluids ◽  
Magnetic Chain

Magnetorheological (MR) fluids are materials that respond to an applied magnetic field with the change of their yield and rheological behaviors. In this paper, the yield and rheological behaviors of MR fluids are discussed. Based on the microstructure of magnetic chain a theoretical model is developed to analyze the effect of an applied magnetic field on the yield stress of MR fluids. Bingham model is used to describe the rheological behaviors of MR fluids subject to an applied magnetic field. The results show that altering the strength of an applied field can control the yield stress of MR fluids. The shear stress increases as the strength of an applied magnetic field increases, and it hardly changes with the increase of shear strain rate. MR fluids exhibit Bingham plastic model.

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.

Properties and Applications of Magnetorheological Fluids

1999 ◽  
Vol 604 ◽  
Author(s):  
M.R. Jolly
Keyword(s):  
Magnetic Field ◽  
Yield Stress ◽  
Applied Magnetic Field ◽  
Rheological Behavior ◽  
Applied Field ◽  
Mechanical Systems ◽  
Magnetorheological Fluids ◽  
Rapid Response ◽  
Basic Composition ◽  
Mr Fluids

AbstractMagnetorheological (MR) fluids are materials that respond to an applied magnetic field with a change in rheological behavior. Typically, this change is manifested by the development of a yield stress that monotonically increases with applied field. Interest in MR fluids derives from their ability to provide simple, quiet and rapid response interfaces between electronic controls and mechanical systems. In this paper, the basic composition and properties of example MR fluids are reviewed. Some contemporary applications of MR fluids are then discussed.

Magnetic field dependent steady-state shear response of Fe3O4 micro-octahedron based magnetorheological fluids

2018 ◽  
Vol 20 (30) ◽  
pp. 20247-20256 ◽  
Author(s):  
A. V. Anupama ◽  
V. B. Khopkar ◽  
V. Kumaran ◽  
B. Sahoo
Keyword(s):  
Magnetic Field ◽  
Steady State ◽  
Yield Stress ◽  
Applied Magnetic Field ◽  
Rheological Behaviour ◽  
Magnetorheological Fluids ◽  
Shear Response ◽  
Field Dependent ◽  
Dynamic Yield ◽  
Magneto Rheological

The magneto-rheological behaviour of fluids containing soft-ferrimagnetic Fe3O4 micro-octahedrons (M = magnetization, τY = dynamic yield-stress and H = applied-magnetic-field).

HIGH VERSUS LOW FIELD VISCOMETRIC CHARACTERIZATION OF BIDISPERSE MR FLUIDS

2007 ◽  
Vol 21 (28n29) ◽  
pp. 4922-4928 ◽  
Author(s):  
G. T. NGATU ◽  
N. M. WERELEY
Keyword(s):  
Magnetic Field ◽  
Yield Stress ◽  
High Field ◽  
Magnetic Flux Density ◽  
Flow Curves ◽  
Bingham Plastic ◽  
Low Field ◽  
Mr Fluids ◽  
Low Magnetic Field

Our bidisperse magnetorheological fluids are suspensions of micron (2-10μm) and nanometer (~40nm) scale magnetic iron particles in silicone or hydraulic oil. Earlier studies were conducted to determine the yield stress of these fluids at low magnetic field induction. These studies have shown the absence of saturation yield stress implying the possibility of a higher yield stress by increasing the applied field. In this study, three different bidisperse MR fluids were investigated to determine the maximum available yield stress that can be obtained at or near saturation magnetic flux density. The iron loading in the fluids varied from 50% to 80% by weight. Two types of MR cells, a low field and a high field cells, were used for the investigation. Using a parallel disc rheometer alternatively equipped with one of the two MR cells, the flow curves of the MR fluids were obtained and their yield stress determined. The yield stress of the MR fluids as a function of applied magnetic field was identified using the Bingham-Plastic constitutive model. Results show that the high field cell (maximum 1 Tesla) was able to measure shear stress up to saturation, whereas the low field cell (maximum 0.26 Tesla) could not.

Upper Critical Field and Irreversibility Line in Bi2Sr2CuO6+δ/CaCuO2 Superconducting Superlattices Obtained by MBE

2000 ◽  
Vol 14 (25n27) ◽  
pp. 2767-2772
Author(s):  
Matteo Salvato ◽  
Carmine Attanasio ◽  
Gerardina Carbone ◽  
Rosalba Fittipaldi ◽  
Tiziana Di Luccio ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Thin Films ◽  
Phase Diagrams ◽  
Applied Magnetic Field ◽  
Three Dimensional ◽  
Upper Critical Field ◽  
Resistivity Measurements ◽  
T Phase ◽  
The Magnetic Field

Resistivity measurements in external applied magnetic field up to 8.5T have been performed on Bi2Sr2CuO6+δ/CaCuO2 superconducting superlattices obtained by MBE. The magnetic field (H) vs. temperature (T) phase diagrams have been determined and the experimental data have been compared with that obtained in the case of Bi2Sr2CuO6+δ thin films deposited with the same technique. A reduction of the anisotropy has been obtained in the case of the superlattices with respect to the case of Bi2Sr2CuO6+δ thin films and a three dimensional behavior has been observed by paraconductivity measurements.

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.

Design of the Magnetic Stamp Film for Electromagnetic-Assisted Transfer Printing

2021 ◽  
Vol 88 (7) ◽  
Author(s):  
Qingmin Yu ◽  
Anran Li ◽  
Xudong Yu ◽  
Honglei Zhou ◽  
Huanyu Cheng
Keyword(s):  
Magnetic Field ◽  
Theoretical Model ◽  
Applied Magnetic Field ◽  
Flexible Electronics ◽  
Interfacial Adhesion ◽  
Magnetic Particles ◽  
Magnetic Film ◽  
Transfer Printing ◽  
Maximum Displacement ◽  
Printing Process

Abstract As a critical step to integrate micro-nano electronic components on the soft substrate, transfer printing allows the facile fabrication of flexible electronics. The key to a successful transfer printing process is to modulate the interfacial adhesion strength at the stamp/device interface. As an advanced approach, electromagnetic-assisted transfer printing explores a sealed chamber with a magnetic stamp film at the bottom that can be reversibly actuated by the externally applied magnetic field. The deflected magnetic stamp film changes the pressure inside the chamber to modulate the interfacial adhesion at the stamp/device interface. Here, we investigate various design considerations and demonstrate a magnetic stamp film with magnetic NdFeB particles dispersed in a silicone polymer. A theoretical model is first established to study the reversible upward (or downward) deformation of the magnetic stamp film in a positive (or negative) magnetic field. The theoretical model reveals the effects of the mass fraction of the magnetic particles, the thickness of the magnetic film, and the magnetic field intensity on the deformation of the film and the transfer printing process. The theoretically predicted linear relationship between the maximum displacement of the magnetic film and the applied magnetic field is validated by finite element analysisand experimental results.

Analysis of Torque in Magnetorheological Rotary Brake

2011 ◽  
Vol 239-242 ◽  
pp. 2297-2301 ◽  
Author(s):  
Ping Wang ◽  
Jin Huang ◽  
Shu Hua Wei
Keyword(s):  
Magnetic Field ◽  
Shear Stress ◽  
Applied Magnetic Field ◽  
Bingham Model ◽  
Operational Principle ◽  
Mr Fluids ◽  
Torque Transmission ◽  
Transmission Ability

A magnetorheological (MR) rotary brake is a device that transmits torque by the shear stress of the MR fluids. In this paper, Bingham model is used to describe the constitutive characteristics of MR fluids subject to an applied magnetic field. The operational principle of the MR rotary brake is introduced. The torque transmitted by MR fluids is analyzed to compute the torque transmission ability in the MR rotary brake.

Study on the Model of Magnetic Flocculation of Magneto-Rheological Fluid

2011 ◽  
Vol 335-336 ◽  
pp. 994-999
Author(s):  
Si Hai Zhao ◽  
Tie Nan Luo
Keyword(s):  
Magnetic Field ◽  
Yield Stress ◽  
Applied Magnetic Field ◽  
Volume Concentration ◽  
Colloidal Suspension ◽  
Magneto Rheological

Magneto-rheological fluid (MRF) is non-colloidal suspension. In this paper, it is introduced that MRF will produce magnetic coagulation at an applied magnetic field by analyzing the interact energy between particles in MRF, and the coagulation is chain-like flocculation. The main reason that MRF produced magnetic coagulation is the direction between chain-like structure and magnetic field is the same. According to the studies above, the formula of yield stress for MRF at an applied magnetic field can be deduced. It can be seen from the formula that there is a square relationship between yield stress of MRF and particle magnetization, and the yield stress of MRF is closely related with volume concentration. The conclusions above match the results of existing experiments very well.

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