Abstract:This article presents the state-of-the-art sensors design based on magneto-rheological (MR) fluid. In smart materials, the magneto-rheological fluid is one of the prominent material, which changes rheological properties on application of magnetic field. The MR fluid is mainly used for designing the dampers, clutches and mounts for heavy vehicle systems. However, the MR fluid can also be used for sensor design applications, which has not been much reported in the literature. This review paper summarizes the des… Show more
“…The principal of damping system in loudspeaker basically can be done by controlling MRF shear yield stress in the surround gap area. This technique is carried out by making changes of the surround resonant occurred frequency due to in viscosity of the MR fluid input electrical current to the coil [28]. Figure 1 shows that O-Ring was designed to accommodate the MRF container by two layers.…”
<span>A novel design of magnetorheological fluids (MRF) based surround device in a loudspeaker system was studied in this article. The main objective of this research is to design a new surround device of the loudspeaker that can be easily controlled its damping. Therefore, it was predicted that the audio pressure level on the loudspeaker could be easily manipulated at a different sound source by applying a certain magnetic field. This function could not be reached using one conventional speaker system. Firstly, a set of an electromagnetic device containing MRF was designed to replace the conventional rubber surround. The magnetic circuit was then evaluated using the finite element method magnetics to study the flux distribution in the MRF area. The current was varied from 0.25 to 0.75 A by an interval of 0.25 A. The magnetic flux resulted from the simulation was then logged and used as the based value for predicting the change of shear yield stress. The base properties of the shear yield stress of the MRF against the magnetic flux was obtained from previous experimental result. Therefore, it was hopefully the prediction could be closed to the real system. Based on the simulation result, the shear yield stress varied from 43 to 49 Mpa or about 15 % increment. </span><span lang="IN">A simple experimental work was carried out. By applying particular direct current into the coil, the sound quality generated by the loudspeaker shows different values</span><span>.</span><span lang="IN"> Based on the preliminary experiment, the level of decibel decreased about 3 dB as the application of magnetic fields. The idea has been proven in this preliminary experimental evaluation.</span>
“…The principal of damping system in loudspeaker basically can be done by controlling MRF shear yield stress in the surround gap area. This technique is carried out by making changes of the surround resonant occurred frequency due to in viscosity of the MR fluid input electrical current to the coil [28]. Figure 1 shows that O-Ring was designed to accommodate the MRF container by two layers.…”
<span>A novel design of magnetorheological fluids (MRF) based surround device in a loudspeaker system was studied in this article. The main objective of this research is to design a new surround device of the loudspeaker that can be easily controlled its damping. Therefore, it was predicted that the audio pressure level on the loudspeaker could be easily manipulated at a different sound source by applying a certain magnetic field. This function could not be reached using one conventional speaker system. Firstly, a set of an electromagnetic device containing MRF was designed to replace the conventional rubber surround. The magnetic circuit was then evaluated using the finite element method magnetics to study the flux distribution in the MRF area. The current was varied from 0.25 to 0.75 A by an interval of 0.25 A. The magnetic flux resulted from the simulation was then logged and used as the based value for predicting the change of shear yield stress. The base properties of the shear yield stress of the MRF against the magnetic flux was obtained from previous experimental result. Therefore, it was hopefully the prediction could be closed to the real system. Based on the simulation result, the shear yield stress varied from 43 to 49 Mpa or about 15 % increment. </span><span lang="IN">A simple experimental work was carried out. By applying particular direct current into the coil, the sound quality generated by the loudspeaker shows different values</span><span>.</span><span lang="IN"> Based on the preliminary experiment, the level of decibel decreased about 3 dB as the application of magnetic fields. The idea has been proven in this preliminary experimental evaluation.</span>
“…Since MR damper can generate high damping force, Do and Choi [18] investigated the design configuration of MRF mount considering vibration control subjected to high load, principal design parameters of the pressure, magnetic field, dimension, the stiffness and damping, and the operation capability. On the other hand, Kaluvan et al [19] reviewed MRF as sensor applications instead of actuators. It has been introduced that MRF can be utilized to measure the resonance of vibration modes, current level, flux magnitude, MRF variable resistor, field-dependent tactile device, and stiffness controllable tactile device.…”
Section: Mrf and Its Developmentmentioning
confidence: 99%
“…The shear storage modulus of the MRE, including 25% volume fraction of magnetic particles, 25%-volume of filler as BASF SQ ® with average 3.9-5 µm in diameter, 50% volume of silicon rubber as Eco-flex ® 00-20 is determined through experiment as [50] G (kPa) = −1283f 4 + 1904f 3 − 271.2f 2 + 73.81f + 55. 19.…”
In this review article, different structural types of the magnetic core required for activation of magnetorheological elastomer (MRE) and magnetorheological fluid (MRF) are introduced in terms of design feature, magnetic flux analysis and performance, installation with primary structure and close relationship to material types. As a first step, dynamic functions related to the chosen models are summarized and discussed according to the magnetic field variations including the field-dependent damping force and torque of the application systems. To address on the practical feasibility, main issues of design process are also pointed out and are discussed stating the manufacturing feasibility and the scaled factors of dynamic variables. Then, after analysing the featured models and dynamic functions, the derivation approaches to establish mathematical models of the magnetic circuit core are provided and compared as a valuable reference for checking both simplicity and accuracy. In this stage, the chosen symbolized magnetic circuit models are clearly described about linear or/and nonlinear behaviours of the input (current) and output (magnetic field). In addition, a couple of commercial software to design the magnetic circuit model is introduced since they can be effectively adopted to analyse the magnetic circuit cores of many application systems utilizing MRE and MRF without any difficulty.
“…Electrorheological (ER) and magnetorheological (MR) fluids due to theability to change their properties under the influence of electric and magnetic field [7][8][9][10], are used in various engineering, such as valves [3,[11][12][13][14][15][16][17][18], hydraulic vibration dampers [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34], hydraulic actuators [35,36], seat suspension for vehicles [37], and hydraulic clutches [38][39][40][41][42][43][44][45].…”
The article introduces the structure and results of experimental research concerning a specifically constructed combined clutch with an electrorheological (ER) fluid, controlled by changing the strength of electric field. The clutch consists of over a dozen parallelly connected hydraulic clutches with ER fluid. The purpose of the experimental research is to identify the steady-state and dynamic characteristics which are vital in the construction process of the combined clutch, including the selection of the control system. Depending on which singular clutch of the combined clutch construction is the one where the electric field is generated, an increase or decrease of the torque value is obtained.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.