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 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.

scholarly journals Study on Lamb Waves in a Composite Phononic Crystal Plate

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 799
Author(s):  
Lili Yuan ◽  
Peng Zhao ◽  
Yong Ding ◽  
Benjie Ding ◽  
Jianke Du ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Band Gap ◽  
Vibration Isolation ◽  
Lamb Waves ◽  
Phononic Crystal ◽  
Volume Ratio ◽  
Geometric Parameters ◽  
Crystal Plate ◽  
Band Gaps ◽  
Frequency Range

In the paper, a phononic crystal plate composed of a magnetorheological elastomer with adjustable band gaps in the low frequency range is constructed. The dispersion relations of Lamb waves are studied by the supercell plane wave expansion method. The transmission responses as well as the displacement fields of Lamb waves are calculated by the finite element method. The influence of geometric parameters on the band gaps, the regulation effect of the volume ratio of Fe particles and the bias magnetic field on the band gaps are analyzed. Based on the numerical results, we find that the volume ratio of Fe particles and the magnetic field affect the band gap effectively. The location and width of the band gaps can be adjusted within a broad frequency range by varying the geometric parameters and magnetic field. We can control the band gap, achieve an appropriate and wide low band gap by selecting proper geometric parameters and applying an external contactless magnetic field to deal with complicated and changeable engineering environment. The results are useful for understanding and optimizing the design of composite vibration isolation plates.

scholarly journals Analysis of vibration resistance of machining technological equipment of a floating workshop in shipbuilding

2021 ◽  
pp. 15-22
Author(s):  
О.В. Владецкий ◽  
Е.В. Хекерт ◽  
Е.А. Владецкая ◽  
А.О. Харченко
Keyword(s):  
Machine Tool ◽  
Vibration Isolation ◽  
Vibration Damping ◽  
Sea Waves ◽  
Internal Factors ◽  
Vibration Resistance ◽  
Floating Base ◽  
Analysis And Synthesis ◽  
Isolation Systems

В статье рассмотрены результаты исследований в направлении совершенствования станочного оборудования для высокоточной обработки деталей в условиях плавучих мастерских путем повышения виброустойчивости технологической системы и снижения вредных воздействий от внешней среды (морского волнения) и соседнего работающего оборудования. Проанализированы традиционные виброизолирующие опоры современных станков, которые невозможно использовать на плавучих мастерских по причине потери ими функционирования в условиях качки плавучего основания и горизонтальных смещений под ее воздействием. Разные способы установки обеспечивают различную степень чувствительности станка к колебаниям основания и возмущениям, действующим в станке. Целью работы является изыскание путей повышения эффективности систем виброизоляции станочного оборудования в условиях плавучей мастерской для обеспечения качества обрабатываемых деталей. Задачей является анализ традиционных виброизолирующих устройств и разработка модели и алгоритма поиска новых структурных вариантов виброизолирующих устройств для уменьшения влияния вибрационных воздействий от внешней среды и внутренних факторов на качество обработки. Выявлено, что на этапах анализа и синтеза на уровне структурно-компоновочной оптимизации виброизолирующих устройств возможно по укрупненным качественным показателям получение рациональных структурных вариантов для шлифовальных станков плавучей мастерской. Установлено, что путем параметрического синтеза и проведения дополнительных теоретических и практических исследований реальных конструкций виброизолирующих устройств, возможно создание новых конструкций виброизолирующего устройства механообрабатывающего технологического оборудования. The article discusses the results of research in the direction of improving machine tool equipment for high-precision machining of parts in floating workshops by increasing the vibration resistance of the technological system and reducing the harmful effects of the environment (sea waves) and neighboring operating equipment. The traditional vibration-isolating supports of modern machines, which cannot be used in floating workshops, due to their loss of functioning under the conditions of the floating base swinging and horizontal displacements under its influence, are analyzed. Different installation methods provide different degrees of machine sensitivity to base vibrations and disturbances in the machine. The aim of the work is to find ways to improve the efficiency of vibration isolation systems for machine tool equipment in a floating workshop to ensure the quality of processed parts. The task is to analyze traditional vibration damping devices and develop a model and an algorithm for searching for new structural variants of vibration damping devices to reduce the influence of vibration effects from the external environment and internal factors on the quality of processing. It was revealed that at the stages of analysis and synthesis at the level of structural and layout optimization of vibration isolation devices, it is possible to obtain rational structural options for grinding machines of a floating workshop based on enlarged quality indicators. It has been established that by means of parametric synthesis and additional theoretical and practical research of real designs of vibration-isolating devices, it is possible to create new designs of vibration-isolating devices of mechanical processing equipment.

Design and analysis of a vibration isolation system with cam–roller–spring–rod mechanism

2021 ◽  
pp. 107754632110005
Author(s):  
Yonglei Zhang ◽  
Guo Wei ◽  
Hao Wen ◽  
Dongping Jin ◽  
Haiyan Hu
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Experimental Studies ◽  
Excitation Amplitude ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Stiffness Characteristic ◽  
Negative Stiffness Mechanism ◽  
Isolation Systems ◽  
Vibration Isolation Performance

The vibration isolation system using a pair of oblique springs or a spring-rod mechanism as a negative stiffness mechanism exhibits a high-static low-dynamic stiffness characteristic and a nonlinear jump phenomenon when the system damping is light and the excitation amplitude is large. It is possible to remove the jump via adjusting the end trajectories of the above springs or rods. To realize this idea, the article presents a vibration isolation system with a cam–roller–spring–rod mechanism and gives the detailed numerical and experimental studies on the effects of the above mechanism on the vibration isolation performance. The comparative studies demonstrate that the vibration isolation system proposed works well and outperforms some other vibration isolation systems.

scholarly journals DESIGN CONCEPT OF TEST STAND FOR DETERMINING PROPERTIES OF MAGNETORHEOLOGICAL ELASTOMERS

2013 ◽  
Vol 7 (3) ◽  
pp. 131-134 ◽  
Author(s):  
Mirosław Bocian ◽  
Jerzy Kaleta ◽  
Daniel Lewandowski ◽  
Michał Przybylski
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Smart Materials ◽  
Vibration Damping ◽  
Test Stand ◽  
Design Concept ◽  
Special Test ◽  
Magnetorheological Elastomers ◽  
Vibration Dampers

Abstract Magnetorheological elastomers (MRE) are “SMART” materials that change their mechanical properties under influence of magnetic field. Thanks to that ability it is possible to create adaptive vibration dampers based on the MRE. To test vibration damping abilities of this material special test stand is required. This article presents design concept for such test stand with several options of testing.

Structural analysis of the trajectories of random processes formed in non-linear vibration isolation systems

2021 ◽  
Author(s):  
A.S. Gusev ◽  
L.V. Zinchenko ◽  
S.A. Starodubtseva
Keyword(s):  
Structural Analysis ◽  
Vibration Isolation ◽  
Fundamental Principle ◽  
Statistical Dependence ◽  
Absolute Maximum ◽  
Time Interval ◽  
Apparent Lack ◽  
The Road ◽  
Isolation Systems ◽  
Non Gaussian

When designing technical structures, the safety of their elements is a fundamental principle. This highlights the significance of the proposed solution to the structural analysis of the trajectories of non-Gaussian stationary processes. The solution aims to acquire source data for calculating the stress-strength reliability of structural elements operating under random loads. We analyze an approach that makes it possible to account for the statistical dependence between processes and their derivatives, despite the apparent lack of correlation between them. The considered approach can be utilized in the design of vibration protection of transport vehicles to calculate the probability of a shock absorber breakdown, the probability of loss of the road-wheel contact, etc. The operation reliability of such systems is defined as the probability that the absolute maximum of the process does not exceed the specified standard level during a certain time interval. The article presents the reliability calculation using structural analysis on the example of a one-dimensional stochastic system.

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