On damping vibrations of three-layered beam containing magnetorheological elastomer

2012 ◽  
Vol 23 (9) ◽  
pp. 1019-1023 ◽  
Author(s):  
Evguenia V Korobko ◽  
Gennadi I Mikhasev ◽  
Zoya A Novikova ◽  
Mikalai A Zhurauski

In this article, we present the results of investigations of viscoelastic properties of magnetorheological elastomer containing carbonyl iron particles. Frequencies of natural vibrations of three-layered beam, supporting constructions of which are made from aluminum, and the inner layer—from magnetorheological elastomer—are calculated, and the dependence of vibrations on induction of the applied magnetic field is obtained. Nonstationary vibrations of the beam at pulse impact of magnetic field are found.

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2447-2453 ◽  
Author(s):  
C. BELLAN ◽  
G. BOSSIS

A magnetoactive elastomer made of micronic carbonyl iron particles, structured in elongated clusters and embedded in a silicon elastomer matrix is studied under traction both in static and dynamic modes. The application of a magnetic field of 120 kA/m induces a change in elastic moduli of about 0.6 MPa at strains of 4 to 5%. Still higher changes (4 MPa) are observed in dynamic storage modulus at low strains (10-4 to 10-3). The shape of the stress-strain curves are explained by taking into account the existence of a fiber like structure.


2018 ◽  
Vol 772 ◽  
pp. 51-55 ◽  
Author(s):  
Nor Azlin Nazira Abd Rahman ◽  
Saiful Amri Mazlan ◽  
Siti Aishah Abdul Aziz ◽  
Nur Azmah Nordin ◽  
Ubaidillah ◽  
...  

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.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3017 ◽  
Author(s):  
Sneha Samal ◽  
Marcela Škodová ◽  
Ignazio Blanco

The smart materials subclass of magnetorheological elastomer (MRE) composites is presented in this work, which aimed to investigate the influence of filler distribution on surface morphology. Iron particles with sizes ranging from 20 to 150 µm were incorporated into the elastomer matrix and a 30% volume fraction (V%) was chosen as the optimal quantity for the filler amount in the elastomer composite. The surface morphology of MRE composites was examined by 3D micro-computed tomography (µCT) and scanning electron microscopy (SEM) techniques. Isotropic and anisotropic distributions of the iron particles were estimated in the magnetorheological elastomer composites. The filler particle distribution at various heights of the MRE composites was examined. The isotropic distribution of filler particles was observed without any influence from the magnetic field during sample preparation. The anisotropic arrangement of iron fillers within the MRE composites was observed in the presence of a magnetic field during fabrication. It was shown that the linear arrangement of the iron particle chain induced magnetization within the composite. Simulation analysis was also performed to predict the particle distribution of magnetization in the MREs and make a comparison with the experimental observations.


2007 ◽  
Vol 334-335 ◽  
pp. 193-196
Author(s):  
Jae Lim You ◽  
B.J. Park ◽  
I.B. Jang ◽  
Hyoung Jin Choi

To enhance dispersion stability of magnetorheological (MR) fluids, hybrid magnetic particles of carbonyl iron (CI)/ poly(vinyl butyral) (PVB) with core/shell microstrcutre (CI-PVB) were prepared, since pure magnetic CI based MR fluid systems show severe sedimentation of the CI particles due to the large density mismatch with the carrier liquid and difficulties in redispersion after caking. The composite particles of CI-PVB have a lower density than that of the pure CI particles, while exhibiting almost original magnetic property of the CI. Both CI and CI-PVB particles were dispersed in mineral oil (20 vol%) and their MR characteristics were examined via a rotational rheometer with a magnetic field supplier. Various characterizations of the CI-PVB particles were performed via SEM, TEM and FT-IR. Both yield stress and flow curve of shear stress as a function of shear rate of the MR fluids were investigated under applied magnetic field strengths.


2018 ◽  
Vol 772 ◽  
pp. 61-65
Author(s):  
Muntaz Hana Ahmad Khairi ◽  
Saiful Amri Mazlan ◽  
Ubaidillah ◽  
Siti Aishah Abdul Aziz ◽  
Norhiwani Mohd Hapipi

This study introduces a sucrose acetate isobutyrate (SAIB) as an additive of magnetorheological elastomers (MREs) to be added in silicone rubber matrix and carbonyl iron particles (CIPs) as their filler. The CIPs were fixed at 60 wt% and two types of MREs sample were fabricated which are isotropic and anisotropic. Rheological properties related to shear storage modulus were measured using a rheometer (MCR 302, Anton Paar). The experimental results demonstrated that the magnetorheological (MR) effect of anisotropic MREs-based Silicone/SAIB was 126 % as compared to isotropic MREs-based Silicone/SAIB, 64%. The fabricated MREs samples were frequency and strain dependent. The relative MR effect for both samples showed decreasing trend with the increment of strain amplitude and excitation frequency.


2007 ◽  
Vol 21 (28n29) ◽  
pp. 4868-4874
Author(s):  
G. BOSSIS ◽  
E. COQUELLE ◽  
C. NOEL ◽  
F. GIULIERI ◽  
A. M. CHAZE

We describe two different systems, the first one based on a magnetorheological elastomer and the second one on magnetic particles inside a liquid crystal. In both system we manage to have chain structures with particles that are not in contact. The effect of the gap between particles on the viscoelastic properties are studied. We show in particular how in magnetorheological elastomers, the energy dissipation is closely related to the creation and the motion of cavities in the gap between the particles. In liquid crystal chaining of particles can occur without applying a magnetic field. This happens if the anchoring of liquid crystal on the surface of the particles is homeotropic. We demonstrate how the combination of elastic defects and of a magnetic field allow to obtain microscopic springs made of a pair of magnetic spheres.


2017 ◽  
Vol 29 (1) ◽  
pp. 24-31 ◽  
Author(s):  
Miao Yu ◽  
Hongping Luo ◽  
Jie Fu ◽  
Pingan Yang

In this article, iron nanowire is synthesized by reducing Fe2+ ion with excessive sodium borohydride in deionized aqueous solution. A kind of dimorphic magnetorheological gel is prepared by partial substitution of carbonyl iron particles with Fe nanowires. Several experimental devices based on the dimorphic magnetorheological gel were fabricated, and the magneto-resistance characteristics under a magnetic field of those devices are systematically tested to research the influence of the Fe nanowire on the conductivity of magnetorheological gel. The experimental results indicated that by adding a certain amount of Fe nanowire, the conductivity of the dimorphic magnetorheological gel can be greatly improved. Moreover, it can be seen that the conductivity of sample 4 (with 6 wt.% Fe nanowire) is increased by about 100 times than sample 1 (without Fe nanowire). The mechanism of Fe nanowire enhances the conductivity of the dimorphic magnetorheological gel, which is investigated by microstructure analysis.


2010 ◽  
Vol 636-637 ◽  
pp. 766-771 ◽  
Author(s):  
Anna Boczkowska ◽  
Stefan F. Awietjan

Magnetorheological elastomers (MREs) were obtained by mixing soft polyurethane and carbonyl-iron particles. The effect of the volume fraction of the ferromagnetic particles on the MREs microstructure and properties, as well as their arrangement in relation to the external magnetic field were investigated. As a ferromagnetic component carbonyl–iron powder, with particle size from 6-9µm, was used. The amount of the carbonyl iron particles was varied from 1.5 to 33.0 %(v/v). The samples were produced with randomly dispersed and aligned carbonyl iron particles. Scanning electron and light microscopy techniques were used for the MRE microstructure observations. The rheological properties (G’, G’’ and tan δ) of the MRE were tested without and with the application of the magnetic field. It was found that the microstructure of MREs, particularly the amount and arrangement of the carbonyl-iron particles, has a significant influence on their rheological and damping properties.


2008 ◽  
Vol 144 ◽  
pp. 244-249 ◽  
Author(s):  
Yousef Razouk ◽  
Eric Duhayon ◽  
Bertrand Nogarede

This paper deals with the development of a new type of composites called "magnetoactivated" polymers and the exploration of some of their potential applications. "Magnetoactivated" polymers consist of small embedding (micron-sized) magnetic particles in a high elastic silicon matrix to render it magnetically active and at the same time mechanically strong. The experimental characterizations obtained (magnetic permeability and Young modulus) were systematically compared with the values resulting from the modeling of this material.The elastic properties of our "magnetoactivated" silicon motive us to use them as pump membranes, the evolution of the displacement of the pump membrane with the applied magnetic field were verified in ANSYS and experimentally for various contents of iron particles in the silicon matrix.


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