Showing papers on "Magnetorheological fluid published in 2019"
TL;DR: In this article, the static and dynamic properties of magnetorheological elastomers (MREs) were evaluated in shear mode as a function of the magnetic flux density, and the particular MRE sample with highest iron particles content (40% volume fraction) was chosen for subsequent dynamic characterizations under broad ranges shear strain amplitude (2.5-20%), excitation frequency (0.1-50) and applied magnetic flux densities (0-450mT).
Abstract: Magnetorheological elastomers (MREs) are novel class of magneto-active materials comprised of micron-sized ferromagnetic particles impregnated into an elastomeric matrix, which exhibit variable stiffness and damping properties in a reversible manner under the application of an external magnetic field. Characterization of highly complex behavior of these active composites is a fundamental necessity to design adaptive devices based on the MREs. This study is mainly concerned with in-depth experimental characterizations of static and dynamic properties of different types of MREs using methods defined in related standards. For this purpose, six different types of MRE samples with varying contents of rubber matrix and ferromagnetic particles were fabricated. The static characteristics of the samples were experimentally evaluated in shear mode as a function of the magnetic flux density. The particular MRE sample with highest iron particles content (40% volume fraction) was chosen for subsequent dynamic characterizations under broad ranges shear strain amplitude (2.5–20%), excitation frequency (0.1–50 Hz) and applied magnetic flux densities (0–450 mT). The results revealed nearly 1672% increase in the MRE storage modulus under the application of a magnetic flux of 450 mT, which confirms the potential of the novel fabricated MRE for control of vibration and noise in various engineering applications.
99 citations
TL;DR: A review of magnetorheological fluids can be found in this paper, which brings out the challenges in methods of preparation, difficulties encountered in storage and use, and possible solutions to overcome the challenges.
Abstract: This review of MRF (magnetorheological fluids or MR fluids) brings out the challenges in methods of preparation, difficulties encountered in storage and use, and possible solutions to overcome the challenges. Magnetorheological fluid in the rheological fluid domain has found use due to its ability to change its shear strength based on the applied magnetic field. Magnetorheological fluids are composed of magnetizable micron-sized iron particles and a non-magnetizable base or carrier fluid along with additives to counter sedimentation and agglomeration. Magnetorheological fluids can respond to external stimuli by undergoing changes in physical properties thus enabling several improved modifications in the existing technology enhancing their application versatility and utility. Thus, magnetorheological fluid, a rheological material whose viscosity undergoes apparent changes on application of magnetic field, is considered as a smart material. Such materials can be used for active and semi-active control of engineering systems. Many studies on the designs of systems incorporating MR fluids, mainly for vibration control and also for other applications including brakes, clutches, dynamometers, aircraft landing gears, and helicopter lag dampers, have emerged over last couple of decades. However, the preparation as well as the maintenance of magnetorheological fluids involves several challenges. Sedimentation is a major challenge, even when stored for moderate periods of time. A comprehensive review is made on the problems confronted in the preparation of magnetorheological fluids as well as sustenance of the properties, for use, over a long period of time. Other problems encountered include agglomeration and in-use thickening (IUT) as well as rusting and crusting. Of interest is the mitigation of these problems so as to prepare fluids with satisfactory properties, and such solutions are reviewed here. The control of magnetorheological fluids and the applications of interest are also reviewed. The review covers additives for overcoming challenges in the preparation and use of magnetorheological fluids that include incrustation, sedimentation, agglomeration, and also oxidation of the particles. The methodology to prepare the fluid along with the process for adding selected additives was reviewed. The results showed an improvement in the reduction of sedimentation and other problems decreasing comparatively. A set of additives for addressing the specific challenges has been summarized. Experiments were carried out to establish the sedimentation rates for compositions with varying fractions of additives. The review also analyzes briefly the gaps in studies on MR fluids and covers present developments and future application areas such as haptic devices.
98 citations
TL;DR: In this paper, the non-dominated sorting genetic algorithm (NSGA-II) was used to optimize the parameters of a precision platform with a well-designed vibration isolation and mitigation (VIM) system.
75 citations
TL;DR: In this article, the authors presented a new mode coupling chatter reduction scheme by assembling an MRE absorber on the spindle to absorb vibration with a specific frequency range, and a semi-active controller was established to control the electrical current applied to the magnetorheological elastomer to trace the chatter frequency.
74 citations
TL;DR: This paper investigates a resistor-capacitor (RC) operator-based hysteresis model for MR dampers under the frame of the “restructured model” proposed by Bai et al. with the RC operator substituting the Bouc-Wen operator.
65 citations
TL;DR: In this paper, a pendulum tuned mass damper is used to suppress damaging vibrations in multi-story buildings across a wide frequency spectrum, which maintain their usefulness across a range of frequencies, unlike passive alternatives.
55 citations
01 Apr 2019
TL;DR: In this article, the properties and the engineering applications of the smart materials, especially in the mechatronics field, are described, and the properties of smart materials are described and analyzed.
Abstract: This paper describes the properties and the engineering applications of the smart materials, especially in the mechatronics field. Even though there are several smart materials which all are very i...
53 citations
TL;DR: In this paper, the effect of the particle size on the Young's modulus of magnetorheological elastomers has been analyzed using laser diffraction measurements and X-ray microtomography measurements.
50 citations
TL;DR: The results show that the proposed system significantly improves both, the vibration attenuation ability and the ride quality of the vehicle.
Abstract: In this paper, Bouc–Wen type magnetorheological fluid damper has been used to monitor the ride quality of a prevailing rail vehicle in lateral vibrations. Modelling of the rail vehicle is done in such a manner that it has an entire 9 degrees of freedom by significant considerations of lateral, roll and yaw motions of the car body, rear, and the front chassis. 200 km/h is considered as train speed for tracks with two varying disturbances. A system consisting of multibody in VI-rail software is provided by a track input and ergo, wheel response it obtained. SIMULINK (software) is responsible for the representation of the motions of the wheel as mathematical models. Two different types of analysis are done firstly with conventional passive lateral damper and secondly with semi-active MR lateral damper in subordinate suspension. To diminish lateral vibrations, the disturbance refusal and non-stop state controller algorithms were executed to manage the damper force. Results acquired are in the form of acceleration and displacement of the center of mass of the body under consideration is done by comparing in terms of reduction indices of their vibrations. A significant improvement in the index is seen in which a semi-active lateral damper is mounted. The results show that the proposed system significantly improves both, the vibration attenuation ability and the ride quality of the vehicle.
50 citations
TL;DR: In this article, the authors proposed a new magnetorheological (MR) damper which can produce sufficient damping force within a few millisecond, which can be achieved by reducing the eddy current around the magnetic field zone.
49 citations
TL;DR: In this article, a versatile magnetorheological plastomer (MRP) based on polycaprolactone (PCL)/thermoplastic polyurethane (TPU) polymer blends was developed.
TL;DR: In this paper, a nonlinear vibration analysis of composite sandwich doubly curved shell with a flexible core integrated with a piezoelectric layer is presented. And the effect of different parameters such as temperature rise, various distributions pattern, magnetic fields and curvature ratio are explored in detail.
Abstract: This is the first research on the nonlinear vibration analysis of composite sandwich doubly curved shell with a flexible core integrated with a piezoelectric layer. By using the higher order shear deformable theory (HSDT) for the face sheets and the third-order polynomial theory for the flexible core, the strains and stresses are obtained. It is assumed a smart model including multiscale composite layers shell with a flexible core and magnetorheological layer (MR) that leading up by the nonlinearity of the in-plane and the vertical displacements of the core. Three-phase composites shells with polymer/Carbon nanotube/fiber (PCF) and polymer/Graphene platelet/fiber (PGF) and Shape Memory Alloy (SMA)/matrix either according to Halpin-Tsai model have been considered. The governing equations of multiscale shell have been derived by implementing Hamilton's principle and solved by multiple scale method. For investigating the correctness and accuracy, this paper is validated by other previous researches. Finally, the effect of different parameters such as temperature rise, various distributions pattern, magnetic fields and curvature ratio are explored in detail.
TL;DR: In this paper, the double of sandwich beams which are coupled by visco-Pasternak medium are investigated, and this system is rested on Winkler found at the museum.
Abstract: In the present research, modeling and vibration analysis of the double of sandwich beams which are coupled by visco-Pasternak medium are investigated. Also, this system is rested on Winkler foundat...
TL;DR: In this article, a DC arc discharge method was used to prepare iron nanoparticles and their morphology, magnetic properties, crystal structures and surfaces chemical composition were examined, which confirmed their nano size, high saturation magnetization and high purity.
TL;DR: Experimental results demonstrate that the quarter car system with the VS and VD suspension performs best in terms of reducing the sprung mass accelerations comparing with other suspensions.
Abstract: As the concept of variable stiffness (VS) and variable damping (VD) has increasingly drawn attention because of its superiority on reducing unwanted vibrations, dampers with property of varying stiffness and damping have been an attractive method to further improve vehicle performance and driver comfort. This paper presents the design, prototyping, modeling, and experimental evaluation of a VS and VD magnetorheological (MR) vehicle suspension system. It was first characterized by an INSTRON machine. Then, a phenomenological model was proposed to capture the characteristics of the damper and TS fuzzy approach was used to model the quarter car system where the proposed damper was installed. Different controllers, including skyhook, short-time Fourier transform and state observer based controller were designed to control the damper. Experimental results demonstrate that the quarter car system with the VS and VD suspension performs best in terms of reducing the sprung mass accelerations comparing with other suspensions.
TL;DR: Wang et al. as mentioned in this paper investigated the impact of temperature on the rheological properties of magnetorheological (MR) grease containing carbonyl iron suspended in lithium-based grease within the temperature range from 10°C to 70°C under influence of temperature.
Abstract: Huixing Wang1, Yancheng Li2,3, Guang Zhang1, Jiong Wang1 1. School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, People’s Republic of China 2. School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo 2007, Australia 3. College of Civil Engineering, Nanjing Tech University, Nanjing 211800, People’s Republic of China Corresponding author: wjiongz@njust.edu.cn; yancheng.li@uts.edu.au Abstract This paper investigates the impact of temperature on the rheological properties of magnetorheological (MR) grease containing carbonyl iron suspended in lithium-based grease within the temperature range from 10°C to 70°Cunder influence of temperature, i.e. from 10°C to 70°C. Lithium-based MR grease with 70% weight fraction of carbonyl iron has beenis firstly prepared by mechanical mixing. The apparent viscosity and shear stress as a function of shear rate under different temperatures and magnetic field strengths are measured and discussed. It is found that the influence of temperature on apparent viscosity is reducingreduces with the increase of magnetic field strength. In addition, in the presence of magnetic field, maximum yield stress gets demonstrates an increase as temperature increases from 50°C to 60°C. The dynamic properties of MR grease are obtained under oscillatory shear test. The influences of strain amplitude, driving frequency and magnetic field on the dynamic properties of MR grease at different temperature are discussed. The results demonstrate that the enhancement of temperature leads to the increase of storage modulus and the reduction of the loss factor. Microstructural variation of grease matrix at different temperature is proposed as an explanation of the rheological changes of MR grease.
TL;DR: In this paper, the elastic response of magnetorheological elastomers (MREs) with isotropic and anisotropic particle distributions is investigated theoretically and experimentally.
Abstract: In this research, a systematic study is conducted on the sample preparation, characterization and microscale modeling of magnetorheological elastomers (MREs) with isotropic and anisotropic particle distributions. Different MRE specimens with silicone rubber as the matrix material and varying content of carbonyl iron particles as magnetizable fillers are fabricated. The quasi-static properties of the samples are characterized experimentally using an advanced rheometer equipped with a magnetorheological device. The elastic response of the MREs at zero magnetic field is first investigated theoretically and experimentally. A microscale modeling approach is then used for predicting the response of the MREs under an external magnetic flux density. The approach is based on the idealized distribution of particles inside the matrix according to the regular lattice models or chain-like structure for isotropic and anisotropic dispersions, respectively. Several lattice types are proposed, and performance of each lattice is compared with their counterparts. Detailed explanation is provided on the behavior of the proposed lattices and changes in the properties of the MREs are described from the microstructure point of view. The results for different lattice models are then compared with the experimental measurements for both isotropic and anisotropic MRE samples.
TL;DR: In this paper, a semi-active method for vibration control of flexible structures using smart materials of electrorheological fluids, magnetorheological fluid and elastomers is presented.
Abstract: Vibration control is very significant issue in various engineering fields such as flexible structures, rotor systems, cable and bridge, and vehicle suspension. So far, three different recipes to suppress or control unwanted vibrations are used: passive, semi-active and active. As well known, the passive method has several limitations, such as the lack of real-time avoidance of the time-varying resonances. On the one hand, active vibration control method is very effective, but it is not attractive in terms of cost due to the use of several actuators and sensors. Therefore, recently semi-active vibration control method is popularly used in many practical environments. This article reviews vibration control of flexible structures using the semi-active method associated with smart materials of electrorheological fluids, magnetorheological fluids and magnetorheological elastomers. Modal characteristics of beam, shell and plate incorporating the core (or layer) of smart materials are deeply investigated and discussed in terms of field-dependent controllability. The field-dependent natural frequency and damping property of the sandwich beam type, plate type and shell type are experimentally identified. Subsequently, an appropriate control scheme based on the field-dependent modal properties is formulated to avoid the resonance behavior. In addition, several sandwich beams which are partially filled and fully filled with the magnetorheological fluid are investigated to understand the effectiveness of the modal property change. It has shown that both damping and stiffness properties of the sandwich structures can be effectively controlled by several ways: the change of the field intensity, the location of cores zones, the partial and full treatment and boundary conditions of the structures. In addition, it has identified that mode shapes of the sandwich plates featuring electrorheological core can be partially and fully controlled by applying the input field to an appropriate zone. Smart flexible structures associated with the field-responsive materials can be effectively used for vibration control due to its controllability of the stiffness and damping as well. However, to successfully implement in real environment, a more sophisticated analytical model considering the
microscopic aspects of the particle motions needs to developed. Moreover, the field-dependent bucking problem and acoustic characteristics of smart structures subjected to external disturbances need to be explored.
Abstract: The need of fine finishing of gears with high shape accuracy increases in various industrial, military and scientific instruments applications for enhancing the working performance, power transmission capability, service life, reliability as well as decreasing noise and vibrations at high speed. The surface asperities, dimensional inaccuracy, rough surface and shape inaccuracy of a gear tooth profile occur because of the high speed of material removal mechanism which leads to undesirable effect such as noise and vibration in the gearbox. Therefore, utilizing the conventional tool for finishing of gears at high material removal rates may increase inaccuracy in gear teeth profile shape due to the transverse grinding lines, burns, fine cracks, uneven stress, and thermal distortion. This paper reports on a novel design of a magnetorheological gear profile finishing (MRGPF) tool and its performance analysis to finish the gear teeth profile with more precisely and accurately. The MRGPF tool is made likely similar to the gear grinding profile wheel tool. To analyze the uniform finishing at the gear tooth profile, the magnetostatic finite element analysis (FEA) is performed to predict the uniform magnetic flux density at the proposed tool surface using Maxwell Ansoft. On the basis of the result obtained of magnetic flux density distribution on its finishing surface, the MRGPF tool is designed and fabricated. Further, the experiments are performed to examine the finishing performance of the newly designed tool on the EN-24 steel spur gear teeth profile. The results attest the significant improvement in finishing of gear teeth profile surface with high shape accuracy (DIN standard). This may result in improvement in scuffing performance, reducing noise and vibrations at high speed, reducing wear rate on gear teeth profile and also provides lower friction and temperature during its functional operation.
TL;DR: Reflecting through this review, structures including a novel flow mode and miniature bypass valves have represented the currently structural and technical features of MR dampers.
Abstract: Owing to unique advantages, magnetorheological fluid (MRF) dampers have been widely adopted in different fields of vibration control. Significant differences of structures occur in diverse fields due to the respective requirements, thus obtaining a large number of MR dampers. Having a good understanding of types, technical characteristics, comprehensive performance, and developing trend and their dependencies on structures are extremely conducive to innovative developments and a market selection. While the fundamental and partial structures are summarized in an existing review, the classification, latest technologies, and developing trend are not involved clearly. Therefore, the current survey aims at a comprehensive supplement in such aspects. The review begins with an introduction of the development, application, and classification. Then, details of three technical routes are revealed, and the development of each type is roughly analyzed. Finally, reflecting through this review, structures including a novel flow mode and miniature bypass valves have represented the currently structural and technical features. Fully considering the latest technologies and future requirements, the developing trend and a variety of applications will be anticipated.
TL;DR: An approach is proposed in this paper where both premise and consequent parameters of fuzzy functions in an ANFIS network are adjusted simultaneously by genetic algorithm (GA) to reduce seismic responses of structures.
Abstract: This research presents designing a control system to reduce seismic responses of structures. Semi-active control of a magnetorheological (MR) damper is used to improve seismic behavior of a 3-story...
TL;DR: In this article, two different shapes of spherical and flake-like soft-magnetic carbonyl iron (CI) microparticles were dispersed in silicone oil to prepare magnetorheological (MR) fluids.
Abstract: Two different shapes of spherical- and flake-like soft-magnetic carbonyl iron (CI) microparticles were dispersed in silicone oil to prepare magnetorheological (MR) fluids. The magnetic-field dependent rheological behaviors of the MR fluids were scrutinized focusing on their shape effect. Saturation magnetization of the flake-shaped CI was obtained to be slightly lower than that of spherical-shaped CI. However, rheological properties of shear stress, shear viscosity, and storage modulus of the flake-shaped CI MR fluid surpassed those of the spherical-shaped CI MR suspension under applied magnetic field strengths. The flake-shaped CI based MR fluid also demonstrated superior sedimentation stability compared with the spherical-shaped CI. This was due to large surface area, suggesting that the anisotropy of CI particles plays an important role in their MR performance.
TL;DR: In this article, a two-core type of a semi-active magnetorheological (MR) damper is designed for an airplane landing gear system, and its landing efficiency is evaluated using two different controllable controllables.
Abstract: In this research, a two-core type of a semi-active magnetorheological (MR) damper is designed for an airplane landing gear system, and its landing efficiency is evaluated using two different contro...
TL;DR: Wang et al. as mentioned in this paper investigated the effect of temperature on the transmission characteristics of high-torque magnetorheological (MR) brake by theoretically analyzing a disc brake, the pressure characteristics of the MRF in axial, and the heat dissipation of an MR brake.
Abstract: This paper aims to investigate the effect of temperature on the transmission characteristics of hightorque magnetorheological (MR) brakes by theoretically analyzing a disc brake, the pressure characteristics of the magnetorheological fluid (MRF) in axial, and the heat dissipation of an MR brake. A high-torque squeezing MRF brake with a water cooling method for heat dissipation is designed and a temperature-torque performance experimental system is established to conduct the experiments. The experimental results indicate that the high-torque squeezing MRF brake exhibits workable pressure characteristics. Meanwhile, the braking torque presents a variation trend that is initially increasing then decreasing when the temperature increases from 25 °C to 150 °C. The magnitude of decrease is approximately 210 N m, which decreases from 1800 to 1590 N m. Moreover, the temperature of the MRF presents an almost linear increase at different slip powers and the rate of temperature rise increases with an increase in slip power. The findings of this study prove that an effective cooling method can be vital to the stable operation of the high-torque MR brakes. Publication Details Wang, N., Liu, X., Krolczyk, G., Li, Z. & Li, W. (2019). Effect of temperature on the transmission characteristics of high-torque magnetorheological brakes. Smart Materials And Structures, 28 (5), 057002-1-057002-9. This journal article is available at Research Online: https://ro.uow.edu.au/eispapers1/2672 Smart Materials and Structures TECHNICAL NOTE • OPEN ACCESS Effect of temperature on the transmission characteristics of high-torque magnetorheological brakes To cite this article: Ningning Wang et al 2019 Smart Mater. Struct. 28 057002 View the article online for updates and enhancements. This content was downloaded from IP address 203.10.91.73 on 15/05/2019 at 05:50
TL;DR: In this paper, a one-step solvothermal method was used to synthesize a new magnetorheological (MR) material to prepare a uniform MR suspension with high performances.
TL;DR: In this article, the role of various additives in enhancing the magnetic field-dependent rheological characteristics of solid and thixotropic matrices-based magnetorheological materials (hereafter referred to as MR solids) is discussed.
Abstract: During the last two decades, magnetorheological (MR) materials have attracted a significant amount of attention because of their tremendous potential for engineering applications. This review focuses on the role of various additives in enhancing the magnetic field-dependent rheological characteristics of solid and thixotropic matrice-based MR materials (hereafter referred to as MR solids). Typically, MR solids consist of solid or semi-solid matrices filled with magnetizable particles. However, additives need to be used to improve their performance such as the MR effect. This parameter is typically determined by the field-dependent dynamic modulus. Three different groups of additives would be introduced in the review namely plasticizers, carbon- and chromium-based additives. Compared to particles in the common matrix without a softener, those in matrices with additives which act as matrix softeners will be aligned easier during curing. In fact, the interfaces bonding between matrix-particles would be improved that subsequently enhanced the magnetically induced viscoelastic properties of MRE. In this review, the influences of several additives on the MR effect of various MR solids including MR elastomers, MR greases, and MR gels, which are recognized as efficient smart materials for practical applications in various engineering fields, are surveyed and discussed.
TL;DR: In this article, the design and multi-physics coupling analysis of a shear-valve-mode magnetorheological fluid damper with different piston configurations is presented.
Abstract: This article presents the design and multi-physics coupling analysis of a shear-valve-mode magnetorheological fluid damper with different piston configurations. The finite element model is built to...
TL;DR: The research work reported in this article is focused on the use of magnetic fluids as active lubricant for improving the performance of hybrid journal bearings, with application to high-precision machine tools.
Abstract: The research work reported in this article is focused on the use of magnetic fluids as active lubricant for improving the performance of hybrid journal bearings, with application to high-precision ...