scholarly journals Experimental investigation of torsional vibration isolation using Magneto Rheological Elastomer

2018 ◽  
Vol 144 ◽  
pp. 01007
Author(s):  
K Praveen Shenoy ◽  
Abhishek Kumar Singh ◽  
K Sai Aditya Raman ◽  
K. V. Gangadharan
Keyword(s):  
Magnetic Field ◽  
Vibration Isolation ◽  
Dynamic Performance ◽  
Torsional Vibrations ◽  
Loading Conditions ◽  
Vibration Isolators ◽  
Rotating Systems ◽  
Modes Of Vibration ◽  
Magneto Rheological ◽  
Average Size

Rotating systems suffer from lateral and torsional vibrations which have detrimental effect on the roto-dynamic performance. Many available technologies such as vibration isolators and vibration absorbers deal with the torsional vibrations to a certain extent, however passive isolators and absorbers find less application when the input conditions are dynamic. The present work discusses use of a smart material called as Magneto Rheological Elastomer (MRE), whose properties can be changed based on magnetic field input, as a potential isolator for torsional vibrations under dynamic loading conditions. Carbonyl Iron Particles (CIP) of average size 5 μm were mixed with RTV Silicone rubber to form the MRE. The effect of magnetic field on the system parameters was comprehended under impulse loading conditions using a custom built in-house system. Series arrangement of accelerometers were used to differentiate between the torsional and the bending modes of vibration of the system. Impact hammer tests were carried out on the torsional system to study its response, in the presence and absence of magnetic field. The tests revealed a shift in torsional frequency in the presence of magnetic field which elucidates the ability of MRE to work as a potential vibration isolator for torsional systems.

A Variable Stiffness Vibration Isolation System Based on Magneto-Rheological Elastomer

2012 ◽  
Vol 452-453 ◽  
pp. 659-662
Author(s):  
Wei Wang ◽  
Yi Min Deng
Keyword(s):  
Shear Modulus ◽  
Vibration Isolation ◽  
Variable Stiffness ◽  
Control Area ◽  
Frequency Range ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Magneto Rheological ◽  
Conventional Type

Vibration isolation is a most widely used vibration protection method.The stiffness of vibration isolators in existing conventional type of vibration isolation system is usually of fixed value. This limits the system in exhibiting its vibration isolation effect in that, it has poor results for lower frequency vibration, especially for resonance frequency. Magneto-rheological elastomer is a new branch of Magneto-rheological materials. It’s an intelligent materials in that it’s shear modulus can be controlled by a magnetic field. It has wide application prospects in the vibration control area. This paper proposes using adjustable stiffness of magneto-rheological elastomer vibration isolation in vibration isolation system. By changing the current of vibration isolators coil to control the shear modulus of magneto-rheological elastomer, it can adjust the stiffness of the isolation system, making the system obtain wider vibration isolation frequency range. By exploying SimuLink software to analyze the vibration isolation system, it is found that such a design is effective and applicable.

scholarly journals Investigation on the Mechanical Properties of MRE Compounds

Machines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 36 ◽  
Author(s):  
Renato Brancati ◽  
Giandomenico Di Massa ◽  
Stefano Pagano
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Smart Materials ◽  
Testing Machine ◽  
Static Test ◽  
Vibration Isolators ◽  
Elastomeric Matrix ◽  
Magneto Rheological ◽  
Stiffness And Damping ◽  
Rheological Effect

This paper describes an experimental investigation conducted on magneto-rheological elastomers (MREs) with the aim of adopting these materials to make mounts to be used as vibration isolators. These materials, consisting of an elastomeric matrix containing ferromagnetic particles, are considered to be smart materials, as it is possible to control their mechanical properties by means of an applied magnetic field. In the first part of the paper, the criteria adopted to define the characteristics of the material and the experimental procedures for making samples are described. The samples are subjected to a compressive static test and are then, adopting a testing machine specially configured, tested for shear periodic loads, each characterized by a different constant compressive preload. The testing machine is equipped with a coil, with which it is possible to vary the intensity of the magnetic field crossing the sample during testing to evaluate the magneto-rheological effect on the materials’ characteristics in terms of stiffness and damping.

Physical modeling and experimental verification of magneto-rheological damper under medium and high frequency excitation

2020 ◽  
pp. 146442072096600
Author(s):  
Fanghui Xu ◽  
Dawei Dong ◽  
Yan Huang ◽  
Shizhe Song ◽  
Bing Yan
Keyword(s):  
Physical Model ◽  
High Frequency ◽  
Vibration Isolation ◽  
Dynamic Performance ◽  
Low Frequency ◽  
Damping Force ◽  
Active Device ◽  
Low Frequency Vibration ◽  
Output Characteristics ◽  
Magneto Rheological

As a promising semi-active device, magneto-rheological damper has been widely used in low-frequency vibration isolation fields (within 20 Hz) such as bridge damping and building seismic resistance. Recently, the application of magneto-rheological damper has extended to medium and high frequency fields such as satellite and power engine vibration control, accompanied with an urgent need of detailed understanding of its output characteristics. In this paper, a comprehensive physical model is established to analyze dynamic performance of the magneto-rheological damper. The model, derived from both Poiseuille and Couette flow, aims to describe the relationship between the flow rate and pressure difference. The compressibility of the magneto-rheological fluid, the inertia of both the fluid and piston assembly, and the friction are involved to capture the medium and high frequency dynamics of the damping force. Theoretical calculation and simulation verification of magnetic circuit are conducted. Then the experiment based on a self-made prototype is carried out. The results show that the damping force calculated by proposed physical model matches well with the experimental results across the predefined range of frequency and coil current levels.

Viscoelastic Materials With Magnetically-Controllable Properties for Vibration Damping and Isolation

2007 ◽  
Author(s):  
Daniel E. Bruch ◽  
William P. Morey ◽  
Eric H. Anderson
Keyword(s):  
Magnetic Field ◽  
Vibration Isolation ◽  
Research Effort ◽  
Dynamic Performance ◽  
Volume Ratio ◽  
Vibration Damping ◽  
Viscoelastic Materials ◽  
Magnetic Components ◽  
Material Heating ◽  
Isolation Systems

Viscoelastic Materials (VEMs) are in widespread use for vibration damping and isolation. Magnetorheological (MR) fluid devices are also increasingly used for vibration control. MR fluids are suspensions of metal particles in various carrier fluids that have properties controllable by imposition of a magnetic field, using mechanisms that suggest analogous manipulation of properties in more solid carrier or base materials. This paper describes a research effort that studied the properties of composite or compound materials that we call MR-VEM. Compared to traditional VEM, the material offers the opportunity to change properties — at a minimum, the stiffness, and to a lesser extent material damping — by application of magnetic fields. Properties can be manipulated with a DC or AC field. Magnetic design studies for MR-VEM compounds are described. The paper focuses on the experimental characterization of dynamic performance of MR-VEM devices for use in vibration isolation systems. Two properties were used as the basis for distinguishing samples: particle fill factor, that is the volume ratio of MR particles to the base VEM, and the magnitude of magnetic field applied while curing the MR-VEM elements. Applied magnetic field was also varied during testing. The compound material performance is studied through a range of experiments. Test data showing a factor of five stiffness adjustability are presented. Limitations imposed by the size of required magnetic components and by material heating are quantified and discussed. Overall, the material shows promise for applications requiring adjustability in effective stiffness. The paper concludes by considering actuation with the materials.

scholarly journals STUDY OF ELASTIC PROPERTIES OF A MAGNETO-RHEOLOGICAL ELASTOMER FOR VIBRO-INSULATION IN VACUUM

2020 ◽  
Vol 6 (1) ◽  
pp. 43-47
Author(s):  
A. M. Bazinenkov ◽  
D. A. Ivanova ◽  
I. A. Efimov ◽  
A. P. Rotar
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Composite Material ◽  
Vibration Isolation ◽  
Magnetorheological Elastomer ◽  
Correct Operation ◽  
Active Vibration ◽  
Magneto Rheological ◽  
Increasing Temperature ◽  
Damping Systems

Magnetorheological elastomer is used in vibration isolation and damping systems; it is promising to use a platform of active vibration isolation in a vacuum to provide vibration protection for the research object. Polymer is a composite material whose rheological properties can change under the influence of a directed magnetic field. For the correct operation of the platform, the constancy of mechanical properties is necessary, which can change during degassing with increasing temperature. The paper presents the results of studies of the mechanical properties of MRE with various compositions prior to degassing in a vacuum. It was found that the elastic modulus of the polymer directly depends on the concentration of filler particles, and no dependence on the presence of surfactants was found.

Analysis of magneto rheological elastomers for energy harvesting systems

2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Shear Strain ◽  
Magnetic Induction ◽  
Magnetic Particles ◽  
Homogeneous Magnetic Field ◽  
Electrical Signal ◽  
Harvesting Systems ◽  
Dc Bias ◽  
Magneto Rheological

Magneto Rheological Elastomers (MREs) are composite materials based on an elastomer filled by magnetic particles. Anisotropic MRE can be easily manufactured by curing the material under homogeneous magnetic field which creates column of particles. The magnetic and elastic properties are actually coupled making these MREs suitable for energy conversion. From these remarkable properties, an energy harvesting device is considered through the application of a DC bias magnetic induction on two MREs as a metal piece is applying an AC shear strain on them. Such strain therefore changes the permeabilities of the elastomers, hence generating an AC magnetic induction which can be converted into AC electrical signal with the help of a coil. The device is simulated with a Finite Element Method software to examine the effect of the MRE parameters, the DC bias magnetic induction and applied shear strain (amplitude and frequency) on the resulting electrical signal.

Experimental investigations on finishing of a brass specimen by magneto-rheological honing technique

2021 ◽  
pp. 251659842110157
Author(s):  
Chinu Kumari ◽  
Sanjay Kumar Chak
Keyword(s):  
Magnetic Field ◽  
Process Parameters ◽  
Surface Finish ◽  
Rotational Speed ◽  
Field Application ◽  
Surface Finishing ◽  
Experimental Investigations ◽  
Significant Parameter ◽  
Magnetizing Current ◽  
Magneto Rheological

Magneto-rheological abrasive honing (MRAH) is an unconventional surface finishing technique that relies on abrasives mixed with a unique finishing fluid, which changes its characteristics on magnetic field application. This process imparts nanometric-level surface finish with a significant amount of uniformity. Rotating motion of the workpiece and continuous reciprocation of the finishing fluid in the MRAH process are recognized as the major aspects for adopting this process in finishing non-magnetic materials. The finishing obtained through the MRAH process relies on the workpiece’s material properties and process parameters such as concentration of abrasives in finishing fluid, rotational speed of the workpiece, and magnetic field strength/magnetizing current. To study the efficacy of MRAH process, a parametric study was conducted by performing few experiments on a brass workpiece. Design of experiment approach was adopted to plan the experiments, and the effect of different values of magnetizing current, the concentration of abrasives, and rotational speed on the surface finish were analyzed through the application of analysis of variance (ANOVA). From ANOVA, the rotational speed was found as the most significant parameter with a contribution of 48.90% on % reduction in roughness value (%∇Ra). Around 57% of roughness reduction was obtained at the optimized value of process parameters.

Energy flow and performance evaluation of inerter-based vibration isolators mounted on finite and infinite flexible foundation structures

2022 ◽  
Vol 14 (1) ◽  
pp. 168781402110704
Author(s):  
Zhuang Dong ◽  
Jian Yang ◽  
Chendi Zhu ◽  
Dimitrios Chronopoulos ◽  
Tianyun Li
Keyword(s):  
Power Flow ◽  
Vibration Isolation ◽  
Vibration Suppression ◽  
Flow Behavior ◽  
Flexible Beam ◽  
Vibration Isolators ◽  
Force Transmissibility ◽  
And Performance ◽  
Flexible Foundation ◽  
Isolation Performance

This study investigates the vibration power flow behavior and performance of inerter-based vibration isolators mounted on finite and infinite flexible beam structures. Two configurations of vibration isolators with spring, damper, and inerter as well as different rigidities of finite and infinite foundation structures are considered. Both the time-averaged power flow transmission and the force transmissibility are studied and used as indices to evaluate the isolation performance. Comparisons are made between the two proposed configurations of inerter-based isolators and the conventional spring-damper isolators to show potential performance benefits of including inerter for effective vibration isolation. It is shown that by configuring the inerter, spring, and damper in parallel in the isolator, anti-peaks are introduced in the time-averaged transmitted power and force transmissibility at specific frequencies such that the vibration transmission to the foundation can be greatly suppressed. When the inerter is connected in series with a spring-damper unit and then in-parallel with a spring, considerable improvement in vibration isolation can be achieved near the original peak frequency while maintaining good high-frequency isolation performance. The study provides better understanding of the effects of adding inerters to vibration isolators mounted on a flexible foundation, and benefits enhanced designs of inerter-based vibration suppression systems.

Study of the Performance of Practical Magneto-Rheological Elastomers

2012 ◽  
Vol 430-432 ◽  
pp. 1979-1983
Author(s):  
Wei Bang Feng ◽  
Xue Yang ◽  
Zhi Qiang Lv
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Magnetic Properties ◽  
External Magnetic Field ◽  
Magnetic Particles ◽  
Poor Performance ◽  
Electrical And Magnetic Properties ◽  
Intelligent Material ◽  
Magneto Rheological

Magneto-rheological elastomer( MR elastomer) is an emerging intelligent material made up of macromolecule polymer and magnetic particles. While a promising wide application it has in the fields of warships vibration controlling for its controllable mechanical, electrical and magnetic properties by external magnetic field, design and application of devices based on it are facing great limitations imposed by its poor performance in mechanical properties and magneto effect. Aiming at developing a practical MR elastomer, a new confecting method was proposed in this paper. Then, following this new method and using a specificly designed solidifying matrix, an amido- polyester MR elastomer was developed with its mechanical property systemically explored.

Influence of Fractional Damping and Time Delay on Maxwell-Voigt Model for Vibration Isolation

2016 ◽  
Author(s):  
Sudhir Kaul
Keyword(s):  
Time Delay ◽  
Dynamic Characteristics ◽  
Vibration Isolation ◽  
Model Parameters ◽  
Fractional Damping ◽  
Vibration Isolators ◽  
Multiple Parameters ◽  
Realistic Representation ◽  
Voigt Model ◽  
Isolation Systems

Models of vibration isolators are very commonly used for the design and analysis of isolation systems. Accurate isolator modeling is critical for a successful prediction of the dynamic characteristics of isolated systems. Isolators exhibit a complex behavior that depends on multiple parameters such as frequency, displacement amplitude, temperature and loading conditions. Therefore, it is important to choose a model that is accurate while adequately representing the relationships with relevant parameters. Recent literature has indicated some inherent advantages of fractional derivatives that can be exploited in the modeling of elastomeric isolators. Furthermore, time delay of damping is also seen to provide a realistic representation of damping. This paper examines the Maxwell-Voigt model with fractional damping and a time delay. This model is compared with the conventional Maxwell-Voigt model (without time delay or fractional damping) and the Voigt model in order to comprehend the influence of fractional damping and time delay on dynamic characteristics. Multiple simulations are performed after identifying model parameters from the data collected for a passive elastomeric isolator. The analysis results are compared and it is observed that the Voigt model is highly sensitive to fractional damping as well as time delay.

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