The development of an adaptive tuned magnetorheological elastomer absorber working in squeeze mode

TLDR: In this paper, the authors developed a compact squeeze MRE absorber and its subsequent performance in various magnetic fields characterized under various frequencies by a vibration testing system, which revealed that the natural frequency of the MRE absorbing working in squeeze mode can be tuned from 37 Hz to 67 Hz.

Abstract: In the past, adaptive tuned vibration absorbers (ATVAs) based on magnetorheological elastomers (MREs) have mainly been developed in a shear working mode. The enhancing effect of MREs in squeeze mode has already been investigated, but ATVAs in squeeze mode have rarely been studied. This paper reports the development of a compact squeeze MRE absorber and its subsequent performance in various magnetic fields characterized under various frequencies by a vibration testing system. The results revealed that the natural frequency of the MRE absorber working in squeeze mode can be tuned from 37 Hz to 67 Hz. Following this, a theoretical model based on magnetic dipole theory was developed to investigate the dynamic performance of the squeeze MRE absorber, and the vibration attenuation of the squeeze MRE absorber was then verified by mounting it on a beam with supports under both ends. The results revealed that the squeeze MRE absorber extended its vibration attenuation range from 37 Hz to 67 Hz while the passive absorber was only effective around 53 Hz.

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University of Wollongong
Research Online
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!e development of an adaptive tuned
magnetorheological elastomer absorber working in
squeeze mode
Shuaishuai Sun
University of Wollongong<<>8@6*25.->*>
Ying Chen
University of WollongongB270,1.7>8@.->*>
Jian Yang
University of Wollongong3B>8@6*25.->*>
Tongfei Tian
University of WollongongH>8@6*25.->*>
Huaxia Deng
Hefei University of Technology
See next page for additional authors
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absorber working in squeeze mode
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The Development of an Adaptive Tuned Magnetorheological Elastomer
Absorber Working in Squeeze Mode
S. S. Sun
1
, Y. Chen
1
, J. Yang
1
, T.F. Tian
1
, H.X. Deng*
2
, W.H. Li*
1
, H. Du
3
, and G. Alici
1
1
School of Mechanical, Material and Mechatronic
Engineering,
University
of
Wollongong, New South Wales, 2522,
A
ustr
alia
2
School of
Instrument
Science and
Opto-electronics Engineering,
Hefei
University
of
Technology,
Heifei, China
3
School of Electrical, Computer and
Telecommunications Engineering,
University
of
Wollongong, New South Wales, Australia
*Corresponding author emails: hxdeng@hfut.edu.cn; weihuali@uow.edu.au
Abstract:
Adaptive tuned vibration absorbers (ATVA) based on magnetorheological elastomers were
mainly developed in a shear working mode. The enhancing effect of MRE in squeeze mode has
already been investigated but an ATVA in squeeze working mode has rarely been studied. This
paper reports on the development of a compact squeeze MRE absorber and its subsequent
performance in various magnetic fields characterised under various frequencies by a vibration
testing system. The results revealed that the natural frequency of the MRE absorber working in
squeeze mode can be tuned from 37 to 67 Hz. Following this, a theoretical model based on
magnetic dipole theory is presented to investigate the dynamic performance of the squeeze MRE
absorber, and then the vibration attenuation of the squeeze MRE absorber was verified by
mounting it to a beam with supports under each end. The results revealed that the squeeze MRE
absorber extended its vibration attenuation range from 37Hz to 67Hz while the passive absorber
was only effective around 53Hz.
Keywords:
Adaptive tuned dynamic vibration absorber (ATVA), Magnetorheological elastomers, Squeeze
working mode, vibration attenuation

1. Introduction
Dynamic vibration absorber (DVA), invented by Frahm in 1911 [1], is an auxiliary mass spring
system that is used to suppress vibration in a structure, and it generally consists of an oscillator, a
stiffness component, and a damping component. The basic principle of operation is transferring
the energy of the objects to the oscillator in the absorber. Because a dynamic vibration absorber
has the advantages of simplicity, stability, high reduction of vibration, low cost and low power
consumption, they are widely used to control vibration in building structures, the automotive
industry, aircraft, generators, earthquake resistance, and engines [2, 3].
DVAs mainly contain three different types which are passive DVA, active DVA and semi-active
DVA. The passive DVA, which consists of mass, spring and a damper, has the advantages of
simple structure and stability. However, it normally only works around the natural frequency
which limits their working range and means they cannot deal with changeable frequency or
multiple frequencies. To overcome these shortcomings, active and semi-active controlled
dynamic vibration absorbers have been studied extensively. Active dynamic vibration absorber
that consists of an oscillator, stiffness component, damping component, and an active force
generator and controller, is one kind of device that uses active force to attenuate vibration. Davis
et al. [4, 5] applied a piezoceramic inertial actuator (PIA) to an adaptively tuned dynamic
vibration absorber (ATVA), and this allowed them to vary its natural frequency from 243 to 257
Hz. Apart from the piezoelectric actuators, the electromagnetic motors, electrical linear motors
and pneumatic springs are also used to develop the active absorber[6, 7]. However, an active
control system normally needs large control forces and a large power source, especially when the
working frequency is far from its natural frequency. Furthermore, an active dynamic vibration
absorber also increases the complexity of the system and decreases its stability, factors that limit
its practical applications[8]. The semi-active DVA is composed by a changeable coefficient,
albeit its composition is similar to a conventional dynamic absorber apart from having a variable
coefficient element. Semi-active dynamic absorbers are generally divided into two major groups:
a mechanical tuning dynamic vibration absorber and a smart material tuning dynamic vibration
absorber. In terms of the mechanical tuning dynamic vibration absorber, Nagaya et al. proposed
and designed a tunable vibration absorber based on a cantilever beam[9], Walsh and Lamancusa
reported on a new tunable absorber having adjustable vanes[10], and Xu et al. developed a

mechanical adaptive tuned vibration absorber by varying the distance between the two
springs[11]. On the other hand, magnetorheological (MR) and electrorheological (ER) materials,
shape memory alloys, and piezoelectric materials are mainly used to develop smart material
based absorbers [12-14].
Magnetorheological elastomer (MRE), as a member of the MR materials family[15], generally
consists of micro-sized magnetic particles dispersed in a non-magnetic matrix. MRE is a smart
material that can vary its stiffness, respond quickly, has a simple structure, and is very stable, and
it can be controlled, attributes that make MRE the ideal smart material from which to develop
vibration attenuation devices, especially an adaptive tunable vibration absorber [16-21]. The
shear working mode MRE absorber has already been investigated by a number of researchers.
Ginder and coworkers did pioneering work on the development of an adaptive tunable vibration
absorber based on MRE[16]. Deng et al. applied MRE to absorbers and also presented a series of
MRE absorbers working in shear mode[22]. Their results indicated that the frequency of a
vibration absorber can be tuned from 55 to 82 Hz. Deng and Gong then developed a compact
and efficient shear working mode MRE absorber where all the components were a part of the
dynamic mass[23]. The same group then extended their research by using an active force to
develop active-
adaptive vibration absorbers to further suppress vibration [24, 25]. Hoang and co-
workers presented a conceptual ATVA with soft MREs to reduce the vibration inherent it vehicle
power train systems[26, 27]. Their numerical results showed that an ATVA with MRE material
can effectively work in a frequency ranging from around 7 to 70 Hz. The above research focused
on the shear working mode of an MRE absorber while research on the MRE working in squeeze
mode presented in existing literature is limited. Popp et al. analysed the MR effect under shear
and squeeze modes based on experimental studies and simulations[28]. In their work two
structures that can be considered as concept MRE absorber working in shear and squeeze mode
were tested, and the results showed that the squeeze working mode MRE absorber had a larger
frequency shift range than the shear MRE absorber. Thus, the squeeze working mode MRE is a
good choice to extend the frequency shift range of MRE absorber. Lerner et al developed a
conceptual squeeze ATVAs by using MRE in squeeze mode[29]. However, the structure of the
absorber is not stable especially when there is no current is applied, which limits its practical
application. Also, the coil and the magnetic conductor cannot function as dynamic mass to
absorb vibration, which decreases its absorption effectiveness. Therefore, the development of a

Frequently asked questions

Q1. What are the contributions mentioned in the paper "The development of an adaptive tuned magnetorheological elastomer absorber working in squeeze mode" ?

The enhancing effect of MREs in squeeze mode has already been investigated, but ATVAs in squeeze mode have rarely been studied. This paper reports the development of a compact squeeze MRE absorber and its subsequent performance in various magnetic fields characterized under various frequencies by a vibration testing system. This journal article is available at Research Online: http: //ro. uow. edu. au/eispapers/3023 The Development of an Adaptive Tuned Magnetorheological Elastomer Absorber Working in Squeeze Mode S. S. Sun, Y. Chen, J. Yang, T. F. Tian, H. X. Deng *, W. H. Li *, H. Du, and G. Alici 1 School of Mechanical, Material and Mechatronic Engineering, University of Wollongong, New South Wales, 2522, Australia 2 School of Instrument Science and Opto-electronics Engineering, Hefei University of Technology, Heifei, China 3 School of Electrical, Computer and Telecommunications Engineering, University of Wollongong, New South Wales, Australia * Corresponding author emails: hxdeng @ hfut. 

Q2. What is the working principle of a squeeze MRE?

The working principle of this MRE is as follows; the magnetic fields generated by the coil can be controlled by the current from an external DC power, its squeeze modulus is determined by the strength of the magnetic field, its modulus determines the stiffness of the ATVA such that any change in the MRE’s stiffness will vary the natural frequency of the ATVA. 

Q3. What was the power supply used to tune the currents of the coil?

One DC power supply (GW INSTEK GPC-3030D, GW GPR-3030D) was used to tune the currents of the coil to control the strength of the magnetic field in the electromagnets and the stiffness of the MRE. 

Q4. What is the composition of a semi-active dynamic vibration absorber?

The semi-active DVA is composed by a changeable coefficient, albeit its composition is similar to a conventional dynamic absorber apart from having a variable coefficient element. 

Q5. What are the main factors that limit the effectiveness of an active dynamic vibration absorber?

an active dynamic vibration absorber also increases the complexity of the system and decreases its stability, factors that limit its practical applications[8]. 

Q6. What materials are used to develop smart material based absorbers?

On the other hand, magnetorheological (MR) and electrorheological (ER) materials, shape memory alloys, and piezoelectric materials are mainly used to develop smart material based absorbers [12-14]. 

Q7. What was the vibration of the base aluminum and absorber mass?

Two accelerometers (CA-YD-106 SINOCERA Piezotronics, Inc.) were used to measure the vibration of the base aluminum and absorber mass. 

Q8. What are the main groups of semi-active dynamic vibration absorbers?

Semi-active dynamic absorbers are generally divided into two major groups: a mechanical tuning dynamic vibration absorber and a smart material tuning dynamic vibration absorber. 

Q9. What is the theoretical approach to predict the compressive modulus of MRE absorbers?

Based on the magnetic dipole method, a theoretical approach, as presented in the Appendix, was developed to predict the magnetically induced compressive modulus ∆ under various magnetic strengths. 

Q10. how much frequency is the squeeze working mode MRE absorber effective?

The results showed that the squeeze working mode MRE absorber suppressed vibration from 37Hz to 67Hz while the passive absorber was only effective around its natural frequency. 

Q11. What is the concept of a squeeze MRE absorber?

Compared to the concept MRE absorber working in squeeze mode in Popp’s paper[28], this squeeze MRE absorber used four guide rods to keep it stable, the coil and magnetic conductor form part of the oscillator, which makes it more efficient and more compact because most components function as a dynamic mass. 

Q12. What was the ss that was connected to the shaker?

The base of the absorber was connected to a shaker (Vibration Test System, AURORA, Model No.: VG 100-8) that was controlled by the signal from the computer. 

Q13. What is the vibration frequency of the squeeze MRE absorber?

The two inside the ss that then verticalconductorbsorptionrree-ofed to beted in phasetransmissibility of the squeeze working mode MRE absorber are:T 〈 〉〈 〉 〈 〉 (1)φ tan 〈 〉 (2)where ω , λ ,ζ . ω is the vibration frequency . 

Q14. What is the purpose of this paper?

This paper reports on the development of a compact squeeze MRE absorber and its subsequent performance in various magnetic fields characterised under various frequencies by a vibration testing system.