MAGNETORHEOLOGICAL ELASTOMERS BASED ON POLYURETHANE/SI-RUBBER HYBRID

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1114-1120 ◽  
Author(s):  
Y. Hu ◽  
Y. L. Wang ◽  
X. Q. Gong ◽  
X. L. Gong ◽  
X. Z. Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Preparation Condition ◽  
Sem Analysis ◽  
Maximum Increase ◽  
Magnetorheological Elastomers ◽  
Testing Conditions ◽  
Preparation Conditions ◽  
The Matrix ◽  
Mr Effect ◽  
The Relationship

A kind of magnetorheological elastomers based on polyurethane (PU)/silicone rubber ( Si -rubber) hybrid is fabricated without applying magnetic fields. The MR effect is improved by optimizing preparation conditions, in particular by adjusting PU/Si -rubber ratio, and improving compatibility between PU and Si -rubber. The influences of the preparation condition and the relationship between the microstructure and MR effect of this kind of magnetorheological elastomers are discussed in detail. The results show that this kind of MR elastomers has better MR effect than that of MR elastomers based on pure Si -rubber or PU matrix with same testing conditions. SEM analysis indicates that the former forms a peculiar interpenetrating microstructure in the presence of PU in the matrix. The maximum increase in shear modulus of this kind of MR elastomers can be up to 0.5MPa when exposed to a magnetic field of about 0.2T.

Study on Epoxy Based Magnetorheological Elastomers

2011 ◽  
Vol 306-307 ◽  
pp. 852-856 ◽  
Author(s):  
Xiang Wang ◽  
He Yi Ge ◽  
Hua Shi Liu
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Iron Content ◽  
Room Temperature ◽  
Magnetorheological Elastomers ◽  
The Matrix ◽  
Mr Effect ◽  
Scanning Electron

To improve the mechanical properties and the MR effect of MRE, we use flexible epoxy as the matrix of MRE. It shows that both the mechanical properties and the MR effect of epoxy based MRE improved. At room temperature the highest absolute modulus increase was 203 MPa when the intensity of magnetic field was 0.2T while the carbonyl iron content was 71.4%. Temperature influenced the MR effect. When at -40°C the maximum storage modulus increased more than 2356 MPa and changed with the temperature. Meanwhile, the morphology of the epoxy based MRE was studied by scanning electron microscopy (SEM).

Magnetorheological Elastomer Silicone-Based Containing Corroded Carbonyl Iron Particles

2018 ◽  
Vol 772 ◽  
pp. 51-55 ◽  
Author(s):  
Nor Azlin Nazira Abd Rahman ◽  
Saiful Amri Mazlan ◽  
Siti Aishah Abdul Aziz ◽  
Nur Azmah Nordin ◽  
Ubaidillah ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Carbonyl Iron ◽  
Dilute Hydrochloric Acid ◽  
Weight Percent ◽  
Iron Particles ◽  
Magnetorheological Elastomer ◽  
Magnetorheological Elastomers ◽  
The Matrix ◽  
Mr Effect ◽  
And Storage

In this study, magnetorheological elastomers (MREs) were synthesized using silicone rubber (SR) as the matrix element interspersed with 70 weight percent of corroded carbonyl iron particles (CIPs). The CIPs were corroded in dilute hydrochloric acid (HCl) for 4 hours. The rheological properties related to MR effect were experimentally examined in the absence and presence of magnetic field at various current using a rheometer. The experimental results depicted the MR effect of the MRE with corroded CIPs decreased one-half, 27% as compared to the non-corroded samples, 58%. The correlation between the purity of CIPs and storage modulus of MR elastomer is examined in this study.

Simulation and Experimental Study of the Coupling Drive Magnetic Field for Embedded Giant Magnetostrictive Actuators

2012 ◽  
Vol 510 ◽  
pp. 322-327
Author(s):  
Bin Wang ◽  
Yi Jie Wu ◽  
Lei Zhang
Keyword(s):  
Magnetic Field ◽  
Matrix Material ◽  
Experimental Tests ◽  
High Frequencies ◽  
Output Displacement ◽  
Close Relationship ◽  
The Matrix ◽  
Magnetostrictive Actuators ◽  
Magnetostrictive Actuator ◽  
The Relationship

Embedded giant magnetostrictive actuator (EGMA) is one of the most important applications of magnetostrictive material. Giant magnetostrictive actuators can deliver big-output displacement and can be driven at high frequencies. These characteristics make them suitable for a variety of positioning. However, because of the limitation of structure, the drive coil and EGMA cannot be any size as needed, so how to maximize the displacement in the limitative situation by optimization becomes the key of design. Several methods are available in the literature, but the coupling drive magnetic field of EGMA and its matrix material is often ignored. In fact, there was a close relationship between the matrix material and the distribution of drive magnetic field. To analyze the relationship, this paper establishes the magnetic circuit model for EGMA. The simulation of the coupling drive magnetic field is also presented. Finally the assumption is validated through experimental tests carried out with two different matrix materials.

Viscoelastic Responses of Silicone-Rubber-Based Magnetorheological Elastomers Under Compressive and Shear Loadings

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Rui Li ◽  
L. Z. Sun
Keyword(s):  
Magnetic Field ◽  
Silicone Rubber ◽  
Viscoelastic Properties ◽  
Mechanical Performance ◽  
Dynamic Stiffness ◽  
Zero Magnetic Field ◽  
Dynamic Strain ◽  
Loading Frequency ◽  
Magnetorheological Elastomers ◽  
Mr Effect

Magnetorheological elastomers (MREs) are adaptive composite materials in the sense that their mechanical properties are tailored by the applied magnetic field. In this paper we developed both isotropic and anisotropic silicone-rubber-based MREs. We examined the zero-magnetic-field dynamic stiffness and damping along with the magnetic field induced changes (the magnetorheological (MR) effect) for the viscoelastic properties of the MREs by conducting both compression and shear investigations. While the anisotropic MREs exhibited substantial magnetic-field-dependent viscoelastic properties at a medium magnetic field, the isotropic ones showed a negligible MR effect. The magnetic filler structure and concentration, loading frequency, and dynamic strain amplitude were all confirmed to play significant roles in the dynamic mechanical performance of the MREs.

Preparation of MgB2 powder for ex situ tape with high Jc-B performance

2008 ◽  
Vol 23 (2) ◽  
pp. 486-493 ◽  
Author(s):  
Takayuki Nakane ◽  
Hiroaki Kumakura
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Critical Current Density ◽  
Heating Time ◽  
The Other ◽  
Ex Situ ◽  
Preparation Process ◽  
Powder Preparation ◽  
Preparation Conditions ◽  
The Relationship

The relationship between the preparation conditions of MgB2 powder and the performance of the critical current density (Jc) of an applied magnetic field (B) of the final ex situ tape produced from it was investigated. The pelletizing pressure of the precursor is crucially important for improving the Jc-B performance of ex situ tape. The higher the pressure, the greater the resulting Jc of the ex situ MgB2 tape. We have shown that the pelletizing pressure used for the precursor mixture during the powder preparation process affects the phases formed in the MgB2. On the other hand, the heating time used is effective in changing the slope of the Jc-B curve of the final tape. This is thought to be due to a change in the crystallinity of the prepared MgB2 powder. The experimental data gathered here will become the basis for investigating the establishment of a guideline for preparing the starting powder used for the manufacture of ex situ MgB2 tape.

Study on the Magnetorheological Effect of MR Elastomer under Shear-compression Mode

2011 ◽  
Vol 239-242 ◽  
pp. 3018-3023 ◽  
Author(s):  
Yu Fei Wang ◽  
Lin He ◽  
Wei Xiong Yu ◽  
Xue Yang
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Shear Strain ◽  
Influence Factor ◽  
Volume Fraction ◽  
Engineering Application ◽  
Magnetorheological Elastomers ◽  
Compression Strain ◽  
Magnetorheological Effect ◽  
Mr Effect

Magnetorheological elastomers are a new kind of MR materials, which consist of magnetizable particles and elastomers. Because of the controllable orheological properties, the materials show a widely prospect in engineering application. In this paper, the magnetic-induced modulus under shear-compression mode was studied. Based on the modulus, the relative MR effect and its influence factor were systematically analyzed. The results show that the relative MR effect will increase with the increasing volume fraction of magnetizable particles, the exterior magnetic field strength and compression strain, and decrease with the increasing shear strain and modulus of matrix. For the study of the relative MR effect, it will give useful advices for the design of MR materials and MR devices.

STUDY OF UTILIZABLE MAGNETORHEOLOGICAL ELASTOMERS

2007 ◽  
Vol 21 (28n29) ◽  
pp. 4875-4882 ◽  
Author(s):  
X. L. GONG ◽  
L. CHEN ◽  
J. F. LI
Keyword(s):  
Magnetic Field ◽  
Strong Magnetic Field ◽  
Carbonyl Iron ◽  
Zero Magnetic Field ◽  
Iron Particles ◽  
Magnetorheological Elastomers ◽  
Vibration Absorption ◽  
Tuned Vibration Absorbers ◽  
Roll Mill ◽  
Mr Effect

This paper presents two kinds of magnetorheological elastomers (MREs). One is composed of appropriate silicon rubber, carbonyl iron particles and some other materials. It is cured under a strong magnetic field at a room temperature. Its shear modulus change from 0.34MPa at zero magnetic field to 3.34MPa at 1T magnetic field, the relative MR effect reaches 878%. Such high MR effect has not been reported until now. The other is composed by appropriate natural rubber, carbonyl iron particles and some other materials. After the compositions are mixed in a two-roll mill, they are cured under a strong magnetic field according to a temperature profile. The increment of its modulus reaches 3.6MPa, and the relative modulus increment is 133%. Their mechanical properties are also evaluated. All observed results show that the fabricated MREs are utilizable. They have successfully been utilized to adaptive tuned vibration absorbers, which will serve for vibration absorption of vehicles.

scholarly journals Effect of Curing Current on Stiffness and Damping Properties of Magnetorheological Elastomers

2018 ◽  
Vol 1 (2) ◽  
pp. 51-58 ◽  
Author(s):  
Norhiwani Hapipi ◽  
Saiful Amri Mazlan ◽  
Siti Aishah Abdul Aziz ◽  
Ubaidillah Ubaidillah ◽  
Seung-Bok Choi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Storage Modulus ◽  
Damping Properties ◽  
Magnetorheological Elastomers ◽  
Three Samples ◽  
Viscoelastic Effects ◽  
Dynamic Performances ◽  
Mr Effect ◽  
Stiffness And Damping ◽  
The Magnetic Field

In this study, the viscoelastic effects of the magnetic field strength imposed for curing process on the stiffness and damping properties of magnetorheological elastomers (MREs) are experimentally investigated. In order to observe the effect, three different samples of MRE are fabricated by imposing curing current of 0.1 A, 0.3 A and 0.5 A which is equivalent to the magnetic field of 70 mT, 309 mT, and 345 mT, respectively. All samples consist of 30% silicone rubber and 70% carbonyl iron particles (CIPs) by weight percentages. After observing the morphological images via SEM, the dynamic performances of these samples, such as storage modulus and loss factor are evaluated and compared as a function of the magnetic field intensity or oscillation frequency. It is shown that the sample cured at 0.5A exhibits the highest storage modulus in the frequency domain. In addition, MR effects of three samples are identified, and it is found that the sample cured at 0.5A shows the highest absolute and relative MR effect.

STUDY OF MECHANICAL BEHAVIOR AND MICROSTRUCTURE OF MAGNETORHEOLOGICAL ELASTOMERS

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1304-1310 ◽  
Author(s):  
X. L. GONG ◽  
X. Z. ZHANG ◽  
P. Q. ZHANG
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Columnar Structure ◽  
Rubber Matrix ◽  
Magnetorheological Elastomers ◽  
Remarkable Effect ◽  
The Matrix ◽  
Chemical Technique ◽  
The Magnetic Field ◽  
Electronic Microscope

Magnetorheological elastomers' mechanical property is greatly influenced by the microstructure of magnetizable particles embedded in the rubber matrix. When synthesizing magnetorheological elastomers, usually the mixture is cured in the presence of a magnetic field and particles are arranged in chainlike or columnar structure after the crosslink, in order to get remarkable effect controlled by the magnetic field. However curing under the magnetic field will face some problems, e.g. the preparation will become not convenient. In this paper magnetorheological elastomers are prepared in various volume fractions in the absence of a magnetic field. Their dynamic viscoelastic properties are tested by a system designed by ourselves. Their microstructures are observed by scan electronic microscope. Finally the inherent relation is revealed between the magnetoviscoelasticity and the distribution of particles in the matrix as well as the components of the mixture and the chemical technique. A kind of typical microstructure is found to be relative to the magnetoviscoelasticity of magnetorheological elastomers prepared in the absence of a magnetic field. This study also provides a guide when designing and preparing this kind of smart materials.

scholarly journals Dual Properties of Polyvinyl Alcohol-Based Magnetorheological Plastomer with Different Ratio of DMSO/Water

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7758
Author(s):  
Norhiwani Mohd Hapipi ◽  
Saiful Amri Mazlan ◽  
Ubaidillah Ubaidillah ◽  
Siti Aishah Abdul Aziz ◽  
Seung-Bok Choi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Polyvinyl Alcohol ◽  
Solvent Mixture ◽  
Binary Solvent ◽  
Solvent Ratio ◽  
Sensors And Actuators ◽  
Relative Shear ◽  
The Matrix ◽  
Mr Effect

Polyvinyl alcohol (PVA)-based magnetorheological plastomer (MRP) possesses excellent magnetically dependent mechanical properties such as the magnetorheological effect (MR effect) when exposed to an external magnetic field. PVA-based MRP also shows a shear stiffening (ST) effect, which is very beneficial in fabricating pressure sensor. Thus, it can automatically respond to external stimuli such as shear force without the magnetic field. The dual properties of PVA-based MRP mainly on the ST and MR effect are rarely reported. Therefore, this work empirically investigates the dual properties of this smart material under the influence of different solvent compositions (20:80, 40:60, 60:40, and 80:20) by varying the ratios of binary solvent mixture (dimethyl sulfoxide (DMSO) to water). Upon applying a shear stress with excitation frequencies from 0.01 to 10 Hz, the storage modulus (G′) for PVA-based MRP with DMSO to water ratio of 20:40 increases from 6.62 × 10−5 to 0.035 MPa. This result demonstrates an excellent ST effect with the relative shear stiffening effect (RSTE) up to 52,827%. In addition, both the ST and MR effect show a downward trend with increasing DMSO content to water. Notably, the physical state of hydrogel MRP could be changed with different solvent ratios either in the liquid-like or solid-like state. On the other hand, a transient stepwise experiment showed that the solvent’s composition had a positive effect on the arrangement of CIPs within the matrix as a function of the external magnetic field. Therefore, the solvent ratio (DMSO/water) can influence both ST and MR effects of hydrogel MRP, which need to be emphasized in the fabrication of hydrogel MRP for appropriate applications primarily with soft sensors and actuators for dynamic motion control.

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