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1

Numerical simulation of single- and multi-step shear stress relaxations of isotropic magnetorheological elastomer using fractional derivative viscoelastic models

Nam T. H., Petríková I., Marvalová B.

Archives of Mechanics

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2022

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Vol. 74, nr 4

251--266

EN

The paper presents numerical simulations of single- and multi-step shear stress relaxations of isotropic magnetorheological elastomer (MRE) using fractional derivative Maxwell and Kelvin–Voigt viscoelastic models. The isotropic MRE has been fabricated by filling micro-sized carbonyl iron particles in silicone rubber. Fractional derivative Maxwell and Kelvin–Voigt viscoelastic models were used to fit the experimental data of the isotropic MRE measured by single- and multi-step relaxation tests at different constant strains and external magnetic fields. The fractional Maxwell viscoelastic model showed a relatively large difference between the measured and calculated results. The fractional Kelvin–Voigt model was fitted well with the experimental data of the isotropic MRE at various constant strain levels under different magnetic fields in both single- and multi-step shear stress relaxations. The calculated shear stress with the long-term prediction is in excellent agreement with the measured one. Therefore, the fractional derivative Kelvin–Voigt viscoelastic model is applicable to predict the long-term stress relaxation of the isotropic MRE.

2

Optimization of pre-structuring parameters in fabrication of magnetorheological elastomer

Lai Ngoc Thien, Ismail Hanafi, Abdullah Mohd Khalil, Shuib Raa Khimi

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 2

557--568

EN

Pre-structuring of magnetic particles during fabrication of magnetorheological elastomer (MRE) is a crucial step, which results in the formation of chain-like columnar structures in the rubber matrix. In this study, MRE based on natural rubber and carbonyl iron particles were prepared. The Taguchi method was utilized to study the effect of several dominating factors during the fabrication process such as pre-curing time, pre-curing temperature and applied magnetic field during curing on the loss tangent (tan δ) and tensile properties. Tan δ was measured through parallel-plate rheometer over a frequency range of 1–100 Hz and a strain amplitude range of 0.1–6%. Tensile properties were measured with a universal tensile testing machine. The obtained data were statistically analyzed using S/N ratios and ANOVA in order to predict the optimal combination of factors, and then further experiments were conducted for verification purpose. Results indicated that the magnetic field had the greatest influence on tan δ when measured over a range of frequency and elongation at break. Furthermore, pre-curing time and magnetic field were found to influence tan δ when measured over a range of strain amplitude. However, none of the factors exhibited significant influence on tensile strength. In addition, the morphology of MRE was examined using scanning electron microscopy (SEM).

3

Semi-active torsional vibration isolation utilizing magnetorheological elastomer

Marzuki W. M. R. W., Muthalif A. G. A., Nordin N. H. D.

Vibrations in Physical Systems

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2018

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Vol. 29

art. no. 2018014

EN

In rotating machinery, unattenuated excessive torsional vibration leads to damage and excessive wear. This type of vibration, which is transferred from one structure to another can be estimated using torsional transmissibility factor (TTF). The value of the TTF describes the ratio of output to input and reaches its peak at the natural frequency. Hence, the ability to vary coupling stiffness of two rotating shafts will allow the control of the TTF towards better performance and preventions from fatigue loading. Traditionally, passive rubbers are used as a flexible coupling in between two shafts. However, the constant passive stiffness of the material limits its performance. To address this issue, an adaptive coupling based on magnetorheological elastomer (MRE) is proposed to achieve better TTF at varying frequencies. Mathematical modelling, simulation study and experimental results of MRE for torsional vibration isolation are presented in this work. Natural frequency obtained from the TTF shows an increase of about 3 Hz when current changed from 1 to 6 A.

4

Testy tłumika magnetoreologicznego

Skalski P.

Autobusy : technika, eksploatacja, systemy transportowe

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2018

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R. 19, nr 12

650--653

PL

W artykule przedstawiono wyniki badań eksperymentalnych prototypu tłumika magnetoreologicznego zaprojektowanego w Instytucie Lotnictwa. Rozwiązanie konstrukcyjne zostało zastrzeżone w Urzędzie Patentowym. W pracy kolejno omówiono zasadę działania tłumika, stanowisko badawcze, oraz wyniki badań. Praca kończy się podsumowaniem.

EN

Paper showed the results of experimental tests of a magnetorheological damper prototype. The damper construction is protected in the Polish Patent Office. In the paper the solution of the damper, the test stand, and results of experiments are presented.

5

Prototyp tłumika magnetoreologicznego

Skalski P.

Autobusy : technika, eksploatacja, systemy transportowe

|

2018

|

R. 19, nr 12

229--232

PL

W artykule został omówiony aktualny stan wiedzy dotyczący tłumików magnetoreologicznych. Następnie zaprezentowano nowe rozwiązanie tłumika z elastomerem magnetoreologicznym, zastrzeżonego w Urzędzie Patentowym. Nowy prototyp tłumika magnetoreologicznego został opracowany w Instytucie Lotnictwa. Artykuł kończy się podsumowaniem.

EN

Paper discussed the State of the Art focused on magnetorheological dampers. Then the new construction solution of a damper with a magnetorheological elastomer was presented. The magnetorheological damper was designed in the Institute of Aviation and was intellectually protected in the Polish Patent Office. The article ends with conclusions.

6

Review of magnetorheological dampers

Skalski P., Ślubowska W.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

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2017

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z. 3/112

69--76

EN

In the paper the comprehensive review of the research and development done on different constructions of magnetorheological dampers. In the introduction part the magnetorheological materials are characterized and examples of magnetorheological dampers are presented. In the next part of this document the construction solutions of dampers with magnetorheological fluids are described. Then in the third Section the dampers with magnetorheological elastomers are shown. At the end, the conclusions are delivered.

PL

W niniejszej publikacji przedstawiony jest kompleksowy przegląd konstrukcji tłumików magnetoreologicznych. We wprowadzeniu scharakteryzowane są materiały magnetoreologiczne i przykłady tłumików magnetoreologicznych są przedstawione. W kolejnej części pracy prezentowane są rozwiązania konstrukcyjne tłumików z cieczą magnetoreologiczną. W części trzeciej tłumiki z elastomerami magnetoreologicznymi są pokazane. Praca kończy się konkluzjami.

7

Role of magnetorheological fluids and elastomers in today’s world

Skalski A., Kalita K.

Acta Mechanica et Automatica

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2017

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Vol. 11, no. 4

267--274

EN

This paper explains the role of magnetorheological fluids and elastomers in today’s world. A review of applications of magnetorheological fluids and elastomers in devices and machines is presented. Magnetorheological fluids and elastomers belong to the smart materials family. Properties of magnetorheological fluids and elastomers can be controlled by a magnetic field. Compared with magnetorheological fluids, magnetorheological elastomers overcome the problems accompanying applications of MR fluids, such as sedimentation, sealing issues and environmental contamination. Magnetorheological fluids and elastomers, due to their ability of dampening vibrations in the presence of a controlled magnetic field, have great potential present and future applications in transport. Magnetorheological fluids are used e.g. dampers, shock absorbers, clutches and brakes. Magnetorheological dampers and magnetorheological shock absorbers are applied e.g. in damping control, in the operation of buildings and bridges, as well as in damping of high-tension wires. In the automotive industry, new solutions involving magnetorheological elastomer are increasingly patented e.g. adaptive system of energy absorption, system of magnetically dissociable [hooks/detents/grips], an vibration reduction system of the car’s drive shaft. The application of magnetorheological elastomer in the aviation structure is presented as well.

8

Rheological investigations of a magnetorheological elastomer

Skalski P.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

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2016

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z. 5/109

99--108

EN

Magneothrological elastomers due to controlled mechanical parameters in an active magnetic field are interesting for researchers and engineers in applications in the automotive industry. In this paper a magnetorheological elastomer based on the natural rubber matrix with carbonyl iron powder was studied. A material sample was fabricated without applying a magnetic field. Its microstructure was observed using a scanning electron microscope. The rheology of the material was investigated with and without an applied magnetic field using the ARES rheometer. Results of investigations were presented and discussed.

PL

Elastomery magnetoreologiczne ze względu na swoje kontrolowane parametry mechaniczne w obecności pola magnetycznego stają się obiektem zainteresowań badaczy oraz inżynierów do aplikacji w przemyśle samochodowym. Próbka materiału elastomeru magnetoreologicznego została przygotowana bez obecnego pola 108 magnetycznego. Struktura elastomeru została zobrazowana na skaningowym mikroskopie elektronowym. Reologia materiału została przeprowadzona na reometrze ARES z obecnym polu magnetycznym oraz bez pola magnetycznego. Wyniki badań zostały przedstawione i poddane dyskusji. Słowa kluczowe: elastomer magnetoreologiczny, guma naturalna, pył karbonylkowy, reologia, badania.

9

Impact absorption system based on MRE with Halbach array

Bocian M., Kaleta J., Lewandowski D., Przybylski M.

Vibrations in Physical Systems

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2016

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Vol. 27

47--54

EN

This paper presents impact absorption system based on magnetorheological elastomer with Halbach magnetic arrays used for tuning. Its design and results of experimental evaluation are presented together with proposition of a non-linear model to describe the system. In the end validation of the model is presented based on energy and power balance method for its parametrization. This paper presents both novel approach to impact absorption and to modelling of a system based on smart material such as magnetorheological elastomer.

10

Aviation Structure With a Magnetorheological Elastomer

Skalski P.

Machine Dynamics Research

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2016

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Vol. 40, No. 3

123--130

EN

In the paper the application of a magnetorheological elastomer (MRE) in an aviation structure was presented. The prototype of the aviation structure with MRE was described. The original, carbon composite model set a reference value of both lift and drag coefficients for an E214 profile. Experiments were conducted in order to evaluate the influence of the magnetorheological elastomer (placed on a surface of a wing) on the overall performance. Results of experiments were depicted and discussed.

11

Application of a magnetorheological elastomer in an aviation structure

Skalski P.

Journal of KONES

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2016

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Vol. 23, No. 3

449--455

EN

Magnetorheological elastomers have properties that can be altered by magnetic field. Many materials were invented more than 30 years ago, but their development and improvement over the past three decades has led to new, more varied uses of these adaptable materials. The main goal of the paper is to present and investigate the application of a magnetorheological elastomer in an aviation structure. The potential advantage of this solution is a possibility to adjust the shape of the wing during the flight by altering the magnetic field strength, which in turn causes deflection of a magnetorheological elastomer. For the purpose of the investigations, an E214 aerofoil has been selected. The original, carbon composite model set a reference value of both lift and drag coefficient for an E214 profile. A thin layer of magnetorheological elastomer was placed on the upper side of the reversed wing. In order to fully understand the effect of such structural change on an aerial profile, the new research stand was designed and manufactured for the purpose of this research in the Institute of Aviation. Experiments were conducted due to evaluate the influence of magnetorheological elastomer on the overall performance. Results of investigations were presented and discussed.

12

Zastosowanie elastomerów magnetoreologicznych w transporcie

Skalski P.

Logistyka

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2015

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nr 3

4398--4402, CD 1

PL

Właściwości elastomerów magnetoreologicznych mogą być kontrolowane za pomocą pola magnetycznego. Wiele materiałów magnetoreologicznych zostało wynalezionych ponad 30 lat temu, ale ich rozwój przez ostatnie trzy dziesięciolecia pozwala na ich wiele różnych zastosowań. Elastomery magnetoreologiczne ze względu na swój charakter tłumienia drgań, w obecności kontrolowanego pola magnetycznego ma duże możliwości zastosowań w transporcie. W przemyśle samochodowym coraz częściej patentowane są nowe rozwiązania zawierające w swojej budowie elastomery magnetoreologiczne. Morfing w zastosowaniach lotniczych cieszy się coraz większym zainteresowaniem, ze względu na możliwość zwiększenia wydajności i efektywności lotu. Dzięki elastomerom MR możliwy staje się rozwój nowych struktur lotniczych.

EN

Magnetorheological elastomers have properties that can be altered by magnetic field. Many magnetorheological materials were invented more than 30 years ago, but their development and improvement over the past three decades has led to new, more varied uses of these adaptable materials. Magnetorheological elastomers due to their nature – vibration damping in the controlled magnetic field have great potential in transport applications. In the automotive industry are increasingly being patented new solutions containing in its structure magnetorheological elastomers. The morphing technology on aircraft has found increased interest over the last decade because it is likely to enhance performance and efficiency over a wider range of flight conditions. With the magnetorheological elastomers becomes development of new aircraft structures, it is more possible.

13

Badania magnetyczne elastomeru magnetoreologicznego

Skalski P., Dębek C.

Logistyka

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2015

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nr 3

4403--4407, CD 1

PL

Właściwości elastomerów magnetoreologicznych mogą być kontrolowane za pomocą pola magnetycznego. Materiały te mają duże możliwości zastosowania w transporcie ale również w innych gałęziach przemysłu. W pracy przedstawiono otrzymywanie elastomerów mr bez obecnego pola magnetycznego. Następnie przeprowadzono badania na magnetometrze z wibrującą próbką. Dokonano analizy wyników i przedstawiono wnioski.

EN

Properties of magnetorheological elastomers can be controlled by magnetic field. These materials have great potential for use in transportation but also in other industries. This paper presents the preparation of mr elastomers without magnetic field. The magnetic investigations of mre samples were performer. The analysis of the results and conclusions are presented.

14

Numerical, experimental and analytical study on MRE used for vibrating pile hammer efficiency improvement

Kwietniewski M., Miedzińska D., Nguyen H. P., Gieleta R., Osiński J.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 73, nr 2

151--156

EN

Purpose: of this paper is a research on Vibratory Pile Hammer (VPH) efficiency improvement with the use of Magnetorheological Elastomer (MRE) controlled with external magnetic field. Design/methodology/approach: The analytical equations are made to describe physical dependence of MRE on VPH work. To describe elastomer properties reduced polynomial model proposed by Oon H. Yeoh was used. The shear tests for Magnetorheological Elastomer of two with different volume of carbonyl-iron particles and its influence on elastomer pillow implemented in VPH were carried out. Tests were carried out in external magnetic field and without it. Numerical analyses were conducted with the use of MSC Software applying Finite Elements Method (FEM). The FE model was built on the experimental boundary conditions. Findings: MRE significantly changes elastic properties under applied magnetic field, what can be used to stiffness and damping properties of the construction control. Research limitations/implications: In further analyses, the test results will be used for the evaluation and selection of MRE regulation system. Practical implications: The presented results were used in modification of Vibratory Pile Hammer to improve its efficiency and a maintain device in resonance. Originality/value: The new application of the phenomenon of MRE stiffness change caused by the variable external magnetic field will allow to keep the mechanical system in resonance.

15

Stealth technology. Yesterday, today and tomorrow

Skalski P., Krupski J.

Logistyka

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2014

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nr 6

9554--9561

EN

Stealth technology continuous to grow in significance with the development of radars and an ever changing battlefield. Nowadays, not only aircraft, but other types of units like helicopters, ships, land vehicles, submarines and missiles are constructed with low-observable technology. This paper covers the most important methods of making objects less visible and less-detectable. The paper will give a short description of radar, infrared, visual, sonar (acoustic), and plasma. Radar absorbing materials, the most researched element of stealth technology, still present enormous potential. Authors of the paper presented a magnetorheological elastomer as a future material in the stealth technology.

PL

Znaczenie technologii stealth ciągle rośnie wraz z rozwojem radarów i zmieniającym się polem bitwy. W dzisiejszych czasach nie tylko samoloty, ale inne jednostki takie jak: śmigłowce, statki, pojazdy lądowe, łodzie podwodne i rakiety są zbudowane z myślą o niskie wykrywalności. Praca ta obejmuje najważniejsze sposoby wytwarzania obiektów mało wykrywalnych. W skrócie przedstawiono opis radaru, podczerwieni, techniki wizualnej, akustycznej (sonar) i plazmy. Materiały pochłaniające fale radarowe, wymagają ciągłych badań. Autorzy pracy przedstawiają elastomer magnetoreologiczny jako materiał w przyszłościowym zastosowaniu w technologii stealth.

16

Various approaches to magnetorheological elastomers structures FE modelling

Miedzińska D., Niezgoda T., Boczkowska A.

Journal of KONES

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2010

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Vol. 17, No. 1

255-260

EN

Magnetorheological elastomers (MREs) are the materials with rheological properties which can be rapidly and reversibly changed in a continuous way by the applied magnetic field. They are the solid analogues of magnetorheological fluids (MRFs) consisting of magnetically permeable particles (such as iron) added to a viscoelastic polymeric material prior to crosslinking. In the paper different approaches to numerical modelling of the magnetorheological elastomers (MREs) structures are presented. The methods of the MRE micro- and macrostructural FE simulations are taken into consideration. The first approach is connected with the microstructural behaviour of the iron particles situated in the pure elastomer and subjected to the mechanical or magnetic load. The second approach is related to global material properties consideration and macrostructural behaviour modelling. The paper shows that there are many ways of such new materials structure behaviour modelling. All the FE analyses always need to be verified with the experiments as well as for macro- and micro scale material reactions, properties and phenomena describing.

17

Numerical simulation of the beam made of magnetorheological elastomer bending in the magnetic field

Miedzińska D., Sławiński G., Boczkowska A.

Journal of KONES

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2010

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Vol. 17, No. 1

261-265

EN

Magnetorheological elastomers (MREs) belong to the group of so-called smart materials, which respond to an external stimulus by changing their viscoelastic properties. Magnetorheological (MR) material can be fluid, gel or solid like material, such as elastomer. The mechanical properties of the MR materials change when subjected to an external magnetic field. The MREs are interesting candidates for the active stiffness and vibration control of structural systems. In the paper the verification process of the applied FE modelling method is presented. The verification is based on the three point bending experiment. The results of that experiment were used to evaluation of the correction on numerical model and analysis. The model was based on the assumption that MRE behaves like an orthotropic material with the material properties o f MRE on the direction along the iron chains - and of a pure elastomer - on the other directions. Such an assumption can be made for the small deformations of a sample, what took place in the considered experiment. The FE modelling method was considered to be correct. On the base of the verified method a FE element model of the MRE beam bending was developed. Such MRE beams are used as "smart" switches that react under the changeable magnetic field.

18

Introduction to n-body simulation of magnetorheological elastomer (MRE) microstructure forming process

Miedzińska D., Łazowski J., Boczkowska A.

Journal of KONES

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2010

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Vol. 17, No. 1

249-253

EN

Magnetorheological elastomers (MREs) are the materials with rheological properties which can be changed in a continuous way, rapidly and reversibly by the applied magnetic field. They are the solid analogues of magnetorheological fluids (MRFs), consisting of magnetically permeable particles (such as iron) added to a viscoelastic polymeric material prior to crosslinking. In the paper the introduction to the n-body simulation of the MRE microstructure forming process is presented. First, the basics of the n-body problem are presented as the planar three-body problem. It is well known, that the planar three-body problem is the problem describing the motion of three point masses in the plane under their mutual Newtonian gravitation. In the paper it is shown how that problem will be applied to the simulation of the phenomena that appeared when the external magnetic field is applied to the chaotically mixed iron particles in the liquid elastomer. Also the physical model of the interactions occurred in such structures are described. The assumptions shown in the paper will be then used for the development of the computer program which calculates the interactions between iron dipoles and describes the movement of the particles in the liquid elastomer under the magnetic field.

19

Numerical investigation of a coupling problem in magnetorheological elastometr FEM simulations

Niezgoda T., Szymczyk W., Boczkowska A.

Journal of KONES

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2008

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Vol. 15, No. 4

393-398

EN

Magnetorheological elastomers contain carbonyl iron particles of diameter of several microns, each that are dispersed in the polymer resin. These particles are grouped in structures like chains. Properties of such materials can be changed by applying an external magnetic field and they can vary in a wide range. When the magnetic field intensity rises, the effective elastic module increases. The resulting modulus increase is rapid, continuous, and reversible. For a relatively high-modulus elastomer matrix such as natural rubber, the fractional modulus increase with magnetic field can exceed 50%, while it can be even larger for low-modulus host materials. Thanks to this property MREs are used in constructions like controlled vibration dampers, absorbers (TVAs), clutches, actuators, stiffness tunable mounts and suspensions, variable impedance surfaces, automotive suspension bushings, valves, brakes, safety restraint systems, semi active control systems, building vibration isolation, etc. The magneto rheological elastomers (MRE) based on carbonyl iron particles-filled polyurethane resin were investigated. Their stiffness can be changed easily by magnetic field. Such a property can be useful in construction of active vibration damping structural elements. The problem of magneto-mechanical coupling was investigated. The coupling was performed in the 2 different ways. Both of the methods were iterative. The first one was performed in the two loops: external loop was performed over forces that loaded internal rows of iron particles (dipoles) and internal where the remaining external rows of dipoles were loaded by displacement that were induced by the forces. The second method used single loop performed over magnetic forces that were applied to external rows of dipoles and were recalculated in subsequent iterations accordingly to the change of distances between rows of dipoles. Iterations were performed until the state of balance was reached. The compliance of results confirms the correctness of applied numerical methods of MRE behaviour under applied magnetic field.