Investigation of vibration damping properties of electroactive polyanthracene/silicone oil dispersions

2021 ◽  
pp. 1045389X2110235
Author(s):  
Gokce Calis Ismetoglu ◽  
Halil Ibrahim Unal
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Silicone Oil ◽  
Vibration Damping ◽  
Elastic Behavior ◽  
Creep Recovery ◽  
Damping Properties ◽  
Sem Image ◽  
Er Fluids

Electrorheological (ER) fluids generate mechanical responses to applied electric field strength via changing their rheological properties from liquid to solid and vice-versa reversibly. As a result of this, ER fluids can be used in the industrial vibration damping systems. In order to increase applicability of ER fluids, it is necessary to understand electric field induced polarization and ER mechanism of different materials. Therefore, the aim of this study is to illuminate ER and vibration damping properties of polyanthracene (PAT), which is a new material for ER studies. PAT was synthesized from anthracene and characterized by several techniques namely: ATR-FTIR spectroscopy, particle size, SEM image, four-point probe conductivity, and magnetic susceptibility measurements. A series of PAT/silicone oil (SO) dispersions having various concentrations were prepared and subjected to dielectric and ER tests. Then, the colloidal stabilities of 20% PAT/SO and 20% PAT/SO/TritonX systems were determined. Dynamic viscoelastic data obtained by the oscillation tests showed that viscous behavior was dominant under zero electric field, whereas elastic behavior was prevailing under external electric field strength and highlighting the vibration damping characteristics of PAT/SO dispersion. In the creep-recovery measurements, the highest %recovery was recorded to be 62% indicating potential industrial use of PAT/SO dispersion.

Investigation of Thermal Conductivity of Alumina/Silicone Oil Electrorheological Fluids

2010 ◽  
Vol 129-131 ◽  
pp. 421-425 ◽  
Author(s):  
Yi Chun Wang ◽  
Xiao Xia Sun ◽  
Xiao Rong Tang ◽  
Fa Cheng Wang
Keyword(s):  
Thermal Conductivity ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Silicone Oil ◽  
Conductivity Measurement ◽  
Electrorheological Fluids ◽  
High Voltage Power Supply ◽  
Heating Device ◽  
Er Fluids

Electrorheological (ER) fluids are new materials with good properties such as dielectric constant, dielectric loss or conductivity, which display remarkable rheological behavior, being able to convert rapidly and repeatedly from a liquid to solid when an electric field is applied or removed. In this study, suspensions of alumina (A) were prepared in silicone oil (SO). The effects of electric field strength and temperature of the suspensions on thermal conductivity were determined. Thermal conductivity measurement in different conditions was carried out via experimental instrument with high-voltage power supply and water heating device to investigate the effects of electric field strength and temperature on ER performance and thermal conductivity. The results show that the thermal conductivity is in accordance with ER properties enhanced by increasing the field strength and decreasing the temperature.

DYNAMIC PERFORMANCE OF CANTILEVER COMPOSITE MORTAR BEAMS WITH ELECTRO-RHEOLOGICAL FLUID

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1703-1709 ◽  
Author(s):  
JINGZHOU LU ◽  
QINGBIN LI
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Physical Mechanism ◽  
Dynamic Performance ◽  
Structural Vibration ◽  
Structural Vibration Control ◽  
Smart Beam ◽  
Er Fluids ◽  
The Impact

The work presented in this paper bears on the feasibility and the operative technology of embedding electro-rheological (ER) fluids into cement mortar. We have made a cantilever mortar beam with controllable ER fluids filled in a central crack for the purpose of investigation on the evolutional rule of frequencies under different electric field strength by hammering test. The experimental results indicated that the influence of electric field strength upon the first frequency is more evident than that upon the second one, whereas that upon the third frequency is very little. In addition, the physical mechanism of the impact of the change of voltage on the frequency of smart beam structures embedded with ER fluids was discussed. This research sets up an experimental basis for the application of ER fluids in the domain of structural vibration control.

Electrorheological Fluid Hysteresis

Materials ◽  
2005 ◽  
Author(s):  
Young Dae Kim ◽  
Daniel De Kee
Keyword(s):  
Shear Rate ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Particle Concentration ◽  
Electrorheological Fluid ◽  
Particle Structure ◽  
Hysteresis Behavior ◽  
Precise Control ◽  
Er Fluids

Electrorheological (ER) fluids are suspensions of polarizable particles dispersed in insulating liquids. They exhibit a rapid and reversible transition from a liquid-like to a solid-like state upon the application of an electric field. The observed shear stress - shear rate hysteresis makes the precise control of the ER mechanical devices very difficult. Hysteresis behavior of TiO2 ER fluids were observed by varying particle concentration, electric field strength, maximum shear rate, and the time of hysteresis loop. In the absence of an electric field, the stress level of the up curve exceeds that of the down curve. The presence of an electric field, reverses this trend. The extent of hysteresis becomes more significant with increasing electric field strength, particle concentration, and maximum shear rate. Hysteresis behavior of TiO2 ER fluids seems to arise mainly due to the change of the particle structure during shearing. To describe the complex rheological behavior of ER fluids, a kinetic theory is presented. Model predictions show qualitative agreement with the experimental hysteresis data.

CHARACTERISTICS OF A YIELD STRESS SCALING FUNCTION FOR ELECTRORHEOLOGICAL FLUIDS

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2636-2642 ◽  
Author(s):  
H. J. CHOI ◽  
J. W. KIM ◽  
M. S. CHO ◽  
C. A. KIM ◽  
M. S. JHON
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Yield Stress ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Critical Evaluation ◽  
Particle Volume ◽  
Scaling Equation ◽  
Er Fluids

The electrorheological (ER) fluids exhibit a drastic change in rheological and electrical properties. Among these properties, yield stress is one of the critical evaluation parameters of the performance of ER devices. The published experimental data of yield dependence on the electric field strength and particle volume fraction are inconsistent due to the time dependence of material properties and measuring conditions. In this paper, we present a universal function, descriptive of the normalized yield stress, via scaling of the applied electric field strength. This scaling equation hybridizes both the polarization and conductivity models. Yield stress data for various ER fluids are collapsed onto a single curve for a broad range of electric field strengths, suggesting that the proposed scaling equation is adequate for predicting the ER property. Furthermore, the yield stresses, obtained from two different measuring techniques (static and dynamics methods), were also examined.

MECHANICAL PROPERTIES OF AN ER FLUID IN TENSILE, COMPRESSION AND OSCILLATORY SQUEEZE TESTS

2001 ◽  
Vol 15 (06n07) ◽  
pp. 714-722 ◽  
Author(s):  
S. L. VIEIRA ◽  
M. NAKANO ◽  
R. OKE ◽  
T. NAGATA
Keyword(s):  
Mechanical Properties ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Silicone Oil ◽  
Strain Curve ◽  
Mechanical Tests ◽  
Damping Force ◽  
Carbonaceous Particles ◽  
Er Fluid

In this work, the mechanical properties of an anhydrous electrorheological fluid made of carbonaceous particles dispersed in silicone oil were determined in tensile, compression and oscillatory squeeze tests. The mechanical tests were carried out on a Mechanical Testling Machine and the device developed for measuring the ER properties was composed of two parallel steel electrodes between which the ER fluid was placed. The mechanical properties were measured for different DC electric field strengths, velocity and initial gap between the electrodes, and the ERF was tested in two different ways: (a) the fluid was placed between the electrodes (configuration 1) and (b) the electrodes were immersed inside the ERF (configuration 2). The results showed that the ER fluid is more resistant to compression than to tensile, and that the shape of the tensile stress-strain curve and the tensile strength varies with the electric field strength and the initial gap between the electrodes. The compressive stress increased with the increase of the electric field strength and with the decrease of the gap size and upper electrode velocity. In oscillatory test, for both configurations 1 and 2, increasing the oscillation frequency f and the number of cycles N produced a decrease of the damping performance of the ER fluid. Besides this, the damping force of each cycle in oscillatory tests increased with N. The electric field also played an important role on the shape of the hysteresis loop (stress as a function of fluid strain) for both configurations.

Optical Measurement of the Electric Field Strength in a Gel Insulator

2016 ◽  
Vol 136 (10) ◽  
pp. 1420-1421
Author(s):  
Yusuke Tanaka ◽  
Yuji Nagaoka ◽  
Hyeon-Gu Jeon ◽  
Masaharu Fujii ◽  
Haruo Ihori
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Optical Measurement

Effect of external magnetic field on lane formation in driven pair-ion plasmas

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Swati Baruah ◽  
U. Sarma ◽  
R. Ganesh
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Coupling Parameter ◽  
Critical Parameters ◽  
Coulomb Coupling ◽  
Lane Formation ◽  
Parameter Values

Lane formation dynamics in externally driven pair-ion plasma (PIP) particles is studied in the presence of external magnetic field using Langevin dynamics (LD) simulation. The phase diagram obtained distinguishing the no-lane and lane states is systematically determined from a study of various Coulomb coupling parameter values. A peculiar lane formation-disintegration parameter space is identified; lane formation area extended to a wide range of Coulomb coupling parameter values is observed before disappearing to a mixed phase. The different phases are identified by calculating the order parameter. This and the critical parameters are calculated directly from LD simulation. The critical electric field strength value above which the lanes are formed distinctly is obtained, and it is observed that in the presence of the external magnetic field, the PIP system requires a higher value of the electric field strength to enter into the lane formation state than that in the absence of the magnetic field. We further find out the critical value of electric field frequency beyond which the system exhibits a transition back to the disordered state and this critical frequency is found as an increasing function of the electric field strength in the presence of an external magnetic field. The movement of the lanes is also observed in a direction perpendicular to that of the applied electric and magnetic field directions, which reveals the existence of the electric field drift in the system under study. We also use an oblique force field as the external driving force, both in the presence and absence of the external magnetic field. The application of this oblique force changes the orientation of the lane structures for different applied oblique angle values.

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