scholarly journals On the shear test of a MR elastomer under magnetic field applied at various angles

2021 ◽  
Author(s):  
Eike Dohmen ◽  
Dmitry Yu Borin
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Silicone Rubber ◽  
Shear Test ◽  
Rubber Matrix ◽  
Shear Direction ◽  
Deformation Effect ◽  
Practical Applications ◽  
Demagnetizing Factor ◽  
Applied External Magnetic Field

Abstract In this paper the influence of the angle between the applied external magnetic field and the mechanical shear direction on the measured elasticity of a magnetorheological (MR) elastomer is addressed. The whole range of magnetic field angles from 0○ to 90○ is analyzed in steps of 5○. Though this dependence is of highest importance for practical applications this issue is rather neglected in previous studies. The work uses MR elastomer specimens based on a silicone rubber matrix containing iron powder in weight fractions of 82 wt.% and 89 wt.%. It has been shown that the measured modulus of elasticity of such composites decreases as the angle between an external magnetic field and applied shear deformation increases. As the framework for the discussion of the findings a macroscopic explanation associated with the magneto-deformation effect as well as an influence of the demagnetizing factor are considered.

Modelling and experimental characterisation of a compressional adaptive magnetorheological elastomer isolator

2021 ◽  
pp. 107754632110253
Author(s):  
Emiliano Rustighi ◽  
Diego F Ledezma-Ramirez ◽  
Pablo E Tapia-Gonzalez ◽  
Neil Ferguson ◽  
Azrul Zakaria
Keyword(s):  
Magnetic Field ◽  
Silicone Rubber ◽  
Magnetic Interaction ◽  
Iron Particle ◽  
Material Model ◽  
Rubber Matrix ◽  
Magnetorheological Elastomer ◽  
Volume Percentage ◽  
Shock Absorbers ◽  
Percent Concentration

This article proposes a simple physical-based model to describe and predict the performance of axially compressed magnetorheological elastomer cylinders used as vibration and shock absorbers. The model describes the magnetorheological elastomer macroscopic stiffness changes because of an externally applied magnetic field from a microscopic composite cell of silicone rubber and carbonyl iron particle. Despite neglecting the material hyperelasticity, anisotropy and adjacent magnetic interaction, the model describes effectively the effect of the magnetic field on the macroscopic modulus of elasticity. The changes in the mechanical properties with the induced magnetic field are measured on samples of different particle concentration based on volume percentage, that is, 10 and 30 percent concentration of iron particles in a silicone rubber matrix. The manufacturing process of the samples is detailed, as well as the experimental validation of the effective stiffness change under a magnetic field in terms of transmissibility and mobility testing. However, the prediction seems to be limited by the linear elastic material model. Predictions and measurements are compared, showing that the model is capable of predicting the tunability of the dynamic/shock absorber and that the proposed devices have a possible application in the reduction of mechanical vibrations.

Analysis of Fluid Film Lubrication of an MHD Journal Bearing Subjected to an Axially Applied External Magnetic Field

2013 ◽  
Vol 437 ◽  
pp. 136-139 ◽  
Author(s):  
Chin Lung Chang ◽  
Yu Min Li ◽  
Hsing Hui Huang ◽  
Jik Chang Leong
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Journal Bearing ◽  
Axial Direction ◽  
Eccentricity Ratio ◽  
Steady State Flow ◽  
Bearing Current ◽  
Applied External Magnetic Field ◽  
Film Lubrication ◽  
Fluid Film Lubrication

This work simulates the steady-state flow field in a magnetohydrodynamic journal bearing. A uniform magnetic field is applied in the axial direction across the bearing. Current results indicate that a crescent-shape secondary flow will develop at E = 0.8. The velocity profiles at the location of the minimum and maximum film thickness are almost independent of the strength of the external magnetic field unless the eccentricity ratio is relatively small and magnetic field is strong. There exists an eccentric dependent threshold Ha beyond which the shear stress on the journal increases with Ha while that on the bearing decreases.

Filamentation instability of a laser beam in an inhomogeneous plasma in an arbitrarily oriented external magnetic field

2013 ◽  
Vol 79 (5) ◽  
pp. 921-926
Author(s):  
A. HASANBEIGI ◽  
A. MOUSAVI ◽  
H. MEHDIAN
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
External Magnetic Field ◽  
Laser Beam ◽  
Short Pulse ◽  
Inhomogeneous Plasma ◽  
Plasma Inhomogeneity ◽  
Short Pulse Laser ◽  
Filamentation Instability ◽  
Applied External Magnetic Field

AbstractThe interaction of a short pulse laser beam with an inhomogeneous plasma has been studied in the presence of an obliquely applied external magnetic field. The dispersion relation and the analytical growth rate have been obtained solving the nonlinear wave equation. It is found that the growth rate and the cut-off wavenumber are strongly influenced by the direction and magnitude of the applied magnetic field. Moreover, the growth rate has been modified by plasma inhomogeneity.

Localized Magnetoelastic Bending Vibration of an Electroconductive Elastic Plate

2006 ◽  
Vol 74 (6) ◽  
pp. 1071-1077 ◽  
Author(s):  
M. Belubekyan ◽  
K. Ghazaryan ◽  
P. Marzocca ◽  
C. Cormier
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Elastic Plate ◽  
Plate Theory ◽  
Free Edge ◽  
Bending Vibrations ◽  
Bending Vibration ◽  
Conductive Medium ◽  
Localized Vibrations ◽  
Applied External Magnetic Field

The study of the magnetoelastic vibrations of a flat plate immersed in a uniform applied external magnetic field is presented. Kirchhoff’s plate theory and the model of a perfect conductive medium are used. The conditions for the existence of localized bending vibrations in the vicinity of the free edge of the plate are established. It is shown that the localized vibrations can be detected and eventually can be eliminated by means of an applied magnetic field.

Sign in / Sign up

Export Citation Format

Share Document