scholarly journals Homopolymer Based Magnetorheological Elastomer

2021 ◽  
pp. 54-57
Author(s):  
Parth Dhrangdhariya ◽  
Sunil Padhiyar ◽  
Prince Mishra
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Vibration Control ◽  
Applied Magnetic Field ◽  
Variable Stiffness ◽  
Rubber Matrix ◽  
Vibration Absorber ◽  
Vibration Isolator ◽  
Magnetorheological Elastomer ◽  
Spring Force

Magnetorheological rubber belongs to the class of ‘Smart Material’ whose mechanical properties can be altered continuously and reversibly by an applied magnetic field. Magnetorheological rubber (MRE’s) are composites that consists of magnetically polarisable particles mixed into rubber matrix. With suitable controlled algorithms, they respond to change in their environment. Purpose of this work is to know more about magnetorheological rubber for active stiffness, vibration control and dampening applications. Although few applications of these materials have been reported in the literature, the possibilities are numerous. They can be used for various applications such as vibration absorber, vibration isolator, variable stiffness bush, spring, force sensors, actuators etc.

scholarly journals A new magnetorheological elastomer torsional vibration absorber: structural design and performance test

2021 ◽  
Vol 12 (1) ◽  
pp. 321-332
Author(s):  
Pu Gao ◽  
Hui Liu ◽  
Changle Xiang ◽  
Pengfei Yan ◽  
Taha Mahmoud
Keyword(s):  
Magnetic Field ◽  
Torsional Vibration ◽  
Performance Test ◽  
Magnetic Circuit ◽  
Circuit Simulation ◽  
Variable Stiffness ◽  
Vibration Absorber ◽  
Vibration Exciter ◽  
Magnetorheological Elastomer ◽  
The Magnetic Field

Abstract. The semi-active torsional vibration absorber can effectively reduce the torsional vibration of the power-train system. In this paper, a new type of variable stiffness torsional vibration absorber with a magnetorheological elastomer (MRE) as an intelligent controlling element is designed, and the modal analysis, frequency-tracking scheme, and damping effects have been studied. A transient dynamic simulation is utilized to validate the rationality of the mechanical structure, the magnetic field parameters of the absorber are matched, and the magnetic circuit simulation analysis and the magnetic field supply analysis are carried out to verify the closed magnetic circuit. The principle prototype of the innovative vibration absorber is manufactured, the magnetic field strength of the absorber is tested by a Gauss meter, and the results show the efficacy of magnetizing the vibration absorber with a conductive slip ring by solving the magnetizing problem of the rotating parts of the vibration absorber. A special-purpose test rig with a torsional vibration exciter as a power source has been implemented. A comparative experiment has been carried out to test the frequency shift characteristics and authenticate the vibration-reduction effect of the new MRE torsional vibration absorber.

Fabrication and Mechanical Properties Study of the Magnetorheological Elastomer

2013 ◽  
Vol 376 ◽  
pp. 148-152 ◽  
Author(s):  
Guang Hui Li ◽  
Xue Gong Huang ◽  
Xiao Yu Gu ◽  
Jiong Wang
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Permanent Magnets ◽  
Variable Stiffness ◽  
Test System ◽  
Magnetorheological Elastomer ◽  
Preparation Methods ◽  
Operating Modes ◽  
Close Form ◽  
Stiffness Loss

Magnetorheological elastomer (MRE) is a novel kind of magnetorheological materials and has been successfully used to control the structure vibration due to its property of variable stiffness under different magnetic field. In order to improve the properties of MRE, it urgently needs to investigate the preparation methods of MRE and build a corresponding test system to evaluate the performance of MRE in different operating modes. In this paper, different magnetic devices for preparing MRE were studied and designed, and the material was fabricated by the permanent magnets with additional permeability equipment at last. Then, according to the SDOF principle, a novel test system was built in order to investigate the mechanical properties of MRE, and exact close-form expressions of the stiffness, loss factor and other mechanical parameters of MRE, under different magnetic field, have been calculated to analyze the properties of MRE.

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.

Designs for an adaptive tuned vibration absorber with variable shape stiffness element

2005 ◽  
Vol 461 (2064) ◽  
pp. 3955-3976 ◽  
Author(s):  
Philip Bonello ◽  
Michael J Brennan ◽  
Stephen J Elliott ◽  
Julian F.V Vincent ◽  
George Jeronimidis
Keyword(s):  
Vibration Control ◽  
Shape Change ◽  
Excitation Frequency ◽  
Variable Stiffness ◽  
Experimental Results ◽  
Vibration Absorber ◽  
Time Varying ◽  
Variable Geometry ◽  
Curved Beams ◽  
Tuned Vibration Absorber

An adaptive tuned vibration absorber (ATVA) with a smart variable stiffness element is capable of retuning itself in response to a time-varying excitation frequency, enabling effective vibration control over a range of frequencies. This paper discusses novel methods of achieving variable stiffness in an ATVA by changing shape, as inspired by biological paradigms. It is shown that considerable variation in the tuned frequency can be achieved by actuating a shape change, provided that this is within the limits of the actuator. A feasible design for such an ATVA is one in which the device offers low resistance to the required shape change actuation while not being restricted to low values of the effective stiffness of the vibration absorber. Three such original designs are identified: (i) A pinned–pinned arch beam with fixed profile of slight curvature and variable preload through an adjustable natural curvature; (ii) a vibration absorber with a stiffness element formed from parallel curved beams of adjustable curvature vibrating longitudinally; (iii) a vibration absorber with a variable geometry linkage as stiffness element. The experimental results from demonstrators based on two of these designs show good correlation with the theory.

Shock attenuation mechanisms of magnetorheological elastomers absorbers: A theoretical analysis

2016 ◽  
Vol 51 (5) ◽  
pp. 721-730 ◽  
Author(s):  
Dingxin Leng ◽  
Xiaojie Wang ◽  
Lingyu Sun ◽  
Faramarz Gordaninejad
Keyword(s):  
Magnetic Field ◽  
Energy Dissipation ◽  
Variable Stiffness ◽  
Rubber Matrix ◽  
Interfacial Friction ◽  
Response Force ◽  
Shock Attenuation ◽  
Interfacial Bond ◽  
Magnetorheological Elastomers ◽  
Shock Absorbers

To predict the dynamic response of shock absorbers based on magnetorheological elastomers and investigate the contributions of various possible energy dissipation mechanisms, a modified four-parameter model of magnetorheological elastomers was proposed, which includes the viscoelastic characteristics of rubber matrix, the variable stiffness and damping property, and the interfacial bond conditions of magnetorheological elastomers under the applied magnetic field. The constitutive equations of magnetorheological elastomers were derived and all parameters were identified based on a published literature. It is theoretically demonstrated that the maximum response force under an impulse input could be attenuated approximately 30% when the magnetic field with 0.57 T is applied. Using the proposed theoretical model, it is shown that the energy dissipation mechanisms mainly come from the interfacial friction between particles and matrix, and the increment on stiffness and dynamic viscosity of the rubber matrix provides reverse contributions to the shock mitigation, while the interfacial bond stiffness has little influence on the response force amplitude. Hence, when magnetorheological elastomers are utilized in shock absorbers, it is suggested to take advantage of the interfacial friction energy.

scholarly journals Some Recent Developments in Adaptive Tuned Vibration Absorbers/Neutralisers

2006 ◽  
Vol 13 (4-5) ◽  
pp. 531-543 ◽  
Author(s):  
Michael J. Brennan
Keyword(s):  
Vibration Control ◽  
Narrow Band ◽  
Notch Filter ◽  
Variable Stiffness ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
The Past ◽  
Tuned Vibration Absorbers ◽  
Control Scheme ◽  
Recent Developments

The vibration absorber has been used for vibration control purposes in many sectors of engineering from aerospace, to automotive to civil, for the past 100 years or so. A limitation of the device, however, is that it acts like a notch filter, only being effective over a narrow band of frequencies. Recent developments have overcome this limitation by making it possible to tune the device over a range of frequencies. This has been achieved by incorporating a variable stiffness element that can be adjusted in real-time. In this paper, some ways in which stiffness change can be achieved in practice are reviewed and some examples of prototype adaptive tuned vibration absorbers (ATVAs) are described. A simple control scheme to automatically tune an ATVA is also presented.

scholarly journals Design of a Real-Time Adaptively Tuned Dynamic Vibration Absorber with a Variable Stiffness Property Using Magnetorheological Elastomer

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Toshihiko Komatsuzaki ◽  
Yoshio Iwata
Keyword(s):  
Variable Stiffness ◽  
Vibration Absorber ◽  
Property Value ◽  
Magnetorheological Elastomer ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Dependent Property ◽  
Dynamic Absorber ◽  
Frequency Tunable ◽  
Tunable Frequency

An elastomer composite with controllable stiffness, known as a magnetorheological elastomer (MRE), is used in a dynamic vibration absorber whose natural frequency is tuned adaptively to the disturbance frequency through the application of an external magnetic field. The field-dependent property test of the fabricated MRE sample shows that the stiffness changes by more than six times compared to the baseline property value at a 40% iron powder volume concentration. The MRE is then used to fabricate a frequency-tunable dynamic absorber for mitigating transient vibrations of a one-degree-of-freedom system. Investigations show that the proposed absorber outperforms a conventional passive-type absorber throughout the tunable frequency range.

scholarly journals Magnetic Field-Dependent Reversal Effect of the Electromagnet- Induced Normal Stress of Magnetorheological Materials

2020 ◽  
Vol 1 (4) ◽  
pp. 1 ◽  
Author(s):  
Taixiang Liu ◽  
Yangguang Xu ◽  
Ke Yang ◽  
Lianghong Yan ◽  
Beicong Huang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Normal Stress ◽  
Applied Magnetic Field ◽  
Smart Materials ◽  
Uniform Magnetic Field ◽  
Magnetic Particles ◽  
Reversal Effect ◽  
Field Dependent

Magnetorheological (MR) materials are a type of magnetoactive smart materials, whose physical or mechanical properties can be altered by applying a magnetic field. In usual, MR materials can be prepared by mixing magnetic particles into non-magnetic matrices. In this work, the electromagnet-induced (or non-uniform magnetic field-induced) normal stress of MR materials is studied. It shows that the stress does not vary monotonically along with the enhancement of the applied magnetic field. There exists a field-dependent reversal effect of the variation of the stress. The reversal effect is thought resulting from that the ratio of interparticle repellent of parallel magnetic particles to the particle-electromagnet attraction gets enlarged along with the enhancement of the field.

Sign in / Sign up

Export Citation Format

Share Document