scholarly journals A Review on Structural Configurations of Magnetorheological Fluid Based Devices Reported in 2018–2020

2021 ◽  
Vol 8 ◽  
Author(s):  
Dezheng Hua ◽  
Xinhua Liu ◽  
Zengqiang Li ◽  
Pawel Fracz ◽  
Anna Hnydiuk-Stefan ◽  
...  
Keyword(s):  
Smart Materials ◽  
Rheological Characteristic ◽  
Magnetorheological Fluid ◽  
Field Application ◽  
Flow Mode ◽  
Shear Mode ◽  
Practical Applications ◽  
Structural Configurations ◽  
Mechanical Devices ◽  
Operational Modes

Magnetorheological fluid (MRF) is a kind of smart materials with rheological behavior change by means of external magnetic field application, which has been widely adopted in many complex systems of different technical fields. In this work, the state-of-the-art MRF based devices are reviewed according to structural configurations reported from 2018 to 2020. Based on the rheological characteristic, the MRF has a variety of operational modes, such as flow mode, shear mode, squeeze mode and pinch mode, and has unique advantages in some special practical applications. With reference to these operational modes, improved engineering mechanical devices with MRF are summarized, including brakes, clutches, dampers, and mounts proposed over these 3 years. Furthermore, some new medical devices using the MRF are also investigated, such as surgical assistive devices and artificial limbs. In particular, some outstanding advances on the structural innovations and application superiority of these devices are introduced in detail. Finally, an overview of the significant issues that occur in the MRF based devices is reported, and the developing trends for the devices using the MRF are discussed.

A New Detector System For The HB5 Stem Instrument

1985 ◽  
Vol 43 ◽  
pp. 134-135
Author(s):  
J.M. Cowley
Keyword(s):  
Dark Field ◽  
Detector System ◽  
Electron Holography ◽  
Small Specimen ◽  
Bright Field ◽  
Multiple Images ◽  
Practical Applications ◽  
Wide Range ◽  
Diffraction Patterns ◽  
Operational Modes

The HB5 STEM instrument at ASU has been modified previously to include an efficient two-dimensional detector incorporating an optical analyser device and also a digital system for the recording of multiple images. The detector system was built to explore a wide range of possibilities including in-line electron holography, the observation and recording of diffraction patterns from very small specimen regions (having diameters as small as 3Å) and the formation of both bright field and dark field images by detection of various portions of the diffraction pattern. Experience in the use of this system has shown that sane of its capabilities are unique and valuable. For other purposes it appears that, while the principles of the operational modes may be verified, the practical applications are limited by the details of the initial design.

4D printing technology, modern era: A short review

2020 ◽  
pp. 92-111
Author(s):  
Khodadad Mostakim ◽  
Nahid Imtiaz Masuk ◽  
Md. Rakib Hasan ◽  
Md. Shafikul Islam
Keyword(s):  
Smart Materials ◽  
Computer Aided Design ◽  
Short Review ◽  
Stimuli Responsive ◽  
4D Printing ◽  
Space Applications ◽  
Printing Technology ◽  
Practical Applications ◽  
Biomedical Technologies ◽  
Novel Material

The advancement in 3D printing has led to the rapid growth of 4D printing technology. Adding time, as the fourth dimension, this technology ushered the potential of a massive evolution in fields of biomedical technologies, space applications, deployable structures, manufacturing industries, and so forth. This technology performs ingenious design, using smart materials to create advanced forms of the 3-D printed specimen. Improvements in Computer-aided design, additive manufacturing process, and material science engineering have ultimately favored the growth of 4-D printing innovation and revealed an effective method to gather complex 3-D structures. Contrast to all these developments, novel material is still a challenging sector. However, this short review illustrates the basic of 4D printing, summarizes the stimuli responsive materials properties, which have prominent role in the field of 4D technology. In addition, the practical applications are depicted and the potential prospect of this technology is put forward.

scholarly journals Characterization of Sputtered Shape Memory Alloy Ni-Ti Films by Cross-sectional TEM and SEM

2008 ◽  
Vol 14 (S3) ◽  
pp. 85-86
Author(s):  
R.M.S. Martins ◽  
A. Mücklich ◽  
N. Schell ◽  
R.J.C. Silva ◽  
K.K. Mahesh ◽  
...  
Keyword(s):  
Thin Films ◽  
Shape Memory ◽  
Smart Materials ◽  
Functionally Graded ◽  
Sensors And Actuators ◽  
Successful Development ◽  
Cross Sectional ◽  
Mechanical Devices ◽  
Ti Films

Ni-Ti Shape Memory Alloys (SMAs) have been attracting attention as smart materials because they can work as sensors and actuators at the same time. Miniaturization of mechanical devices is evolving toward sub-micron dimensions raising important questions in the properties of Ni-Ti films. In thin films it is essential to investigate the microstructure to understand the origin of the thickness limit. The design of functionally graded films has also been considered but for their successful development it is important to characterize the variations in crystalline structure.

Wear Behavior of Rotary Lip Seal Operating in a Magnetorheological Fluid Under Magnetic Field Conditions

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Peng Zhang ◽  
Kwang-Hee Lee ◽  
Chul-Hee Lee
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Wear Behavior ◽  
High Volume ◽  
Magnetorheological Fluid ◽  
Engine Oil ◽  
Wear Properties ◽  
Lip Seal ◽  
Sealing Performance ◽  
Stiffness And Damping

A magnetorheological fluid (MRF) is one of many smart materials that can be changed their rheological properties. The stiffness and damping characteristics of MRF can be changed when a magnetic field is applied. This technology has been successfully employed in various low and high volume applications, such as dampers, clutches, and active bearings, which are already in the market or are approaching production. As a result, the sealing performance of MRF has become increasingly important. In this study, the wear properties of seals with MRFs were evaluated by a rotary-type lip seal wear tester. The test was performed with and without a magnetic field. The leakage time was monitored during the tests in typical engine oil conditions. The results showed that the wear resistance of the seal with MRF was decreased under the magnetic field.

Effect of Internal Pressure on Flow Properties of Magnetorheological Fluids

2011 ◽  
Author(s):  
Andrea Spaggiari ◽  
Eugenio Dragoni
Keyword(s):  
Internal Pressure ◽  
System Design ◽  
Flow Mode ◽  
Shear Mode ◽  
Mr Fluid ◽  
Mr Fluids ◽  
Experimental Apparatus ◽  
Gear Pumps ◽  
Strengthen Effect ◽  
Hydraulic System Design

Magnetorheological (MR) fluids have a lot of applications in the industrial world, but sometimes their properties are not performing enough to meet system requirements. It has been found that in shear mode MR fluids exhibits a pressure dependency called squeeze strengthen effect. Since a lot of MR fluid based devices work in flow mode (i.e. dampers) this paper investigates the behaviour in flow mode under pressure. The system design is articulated in three steps: hydraulic system design, magnetic circuit design and design of experiment. The experimental apparatus is a cylinder in which a translating piston displaces the fluid without the use of standard gear pumps, incompatible with MR fluids. The experimental apparatus measures the MR fluid yield stress as a function of pressure and magnetic field allowing the yield shear stress to be calculated. A statistical analysis of the results shows that the squeeze strengthen effect is present in flow mode as well and the presence of internal pressure is able to enhance the performance of MR fluid by nearly ten times.

Thermal and tribological performance of graphite flake based magnetorheological fluid under shear mode clutch

2021 ◽  
pp. 1-24
Author(s):  
Manish Kumar Thakur ◽  
Chiranjit Sarkar
Keyword(s):  
Research Work ◽  
Magnetorheological Fluid ◽  
Tribological Performance ◽  
Graphite Flake ◽  
Shear Mode ◽  
Torque Sensor ◽  
Test Rig ◽  
Mr Fluid ◽  
Mr Fluids ◽  
Torque Transmission

Abstract In this research work, graphite flake has been used as an additive in magnetorheological (MR) fluid to improve its thermal and tribological performance. MR fluids with varying amounts of graphite flakes (0.5, 1, 2, 3, 4, and 5 wt%) are prepared to show effective thermal and tribological performance. A test rig is developed with a DC motor, torque sensor, and MR clutch operated in a shear mode to test the torque transmission. Results show the lubrication effects of graphite flakes in MR fluid. Torque transmission is improved in on-state and off-state using graphite flakes based MR fluid as compared to conventional MR fluid. Heating of MR clutch is also reduced with the graphite flakes based MR fluid. Wear marks and damages are decreased significantly with the increased amount of graphite flakes as found in surface roughness tests. SEM and EDS are used to characterize the worn surfaces. This research provides information about the effectiveness of graphite flakes in the MR clutch to improve the device's performance.

scholarly journals Damping in magnetorheological elastomers under compressive stress

2019 ◽  
Vol 254 ◽  
pp. 06002 ◽  
Author(s):  
Mateusz Kukla ◽  
Krzysztof Talaśka ◽  
Ireneusz Malujda
Keyword(s):  
Smart Materials ◽  
Hysteresis Loops ◽  
Machine Construction ◽  
Vibration Absorbers ◽  
Magnetorheological Elastomers ◽  
Practical Applications ◽  
Mechanical Hysteresis ◽  
Compressive Stresses ◽  
Active Vibration ◽  
Energy Absorbers

Magnetorheological elastomers are an important area of study in non-classical engineering materials. These are smart materials, in which some of the physical properties are dependent on the applied magnetic field. This unique property allows to suggest new, innovative practical applications. It is therefore relevant to carry out studies in the possible application of magnetorheological elastomers in machine construction. The present article presents the results of study regarding the properties of the discussed materials subject to compressive stresses. Particular attention is given to the observed growth of surface area of mechanical hysteresis loops, which is evidence of the possibility to change the damping properties of magnetorheological elastomers. This property can be utilized in the construction of different types of machines and devices. These mostly applies to energy absorbers such as active vibration absorbers.

A recurrent neural network–based model for predicting bending behavior of ionic polymer–metal composite actuators

2020 ◽  
Vol 31 (17) ◽  
pp. 1973-1985
Author(s):  
Hojat Zamyad ◽  
Nadia Naghavi ◽  
Reza Godaz ◽  
Reza Monsefi
Keyword(s):  
Smart Materials ◽  
Autoregressive Models ◽  
Metal Composite ◽  
Ionic Polymer Metal Composite ◽  
Ionic Polymer Metal Composites ◽  
Ionic Polymer ◽  
Practical Applications ◽  
Proposed Model ◽  
Polymer Metal ◽  
Application Potential

The high application potential of ionic polymer–metal composites has made the behavior identification of this group of smart materials an attractive area. So far, several models have been proposed to predict the bending of an ionic polymer–metal composite actuator, but these models have some weaknesses, the most important of them are the use of output data (in autoregressive models), high complexity to achieve a proper precision (in non-autoregressive models), and lack of compatibility with the behavioral nature of the material. In this article, we present a hybrid model of parallel non-autoregressive recurrent networks with internal memory cells to overcome existing weaknesses. The validation results on experimental data show that the proposed model has acceptable accuracy and flexibility. Moreover, simplicity and compatibility with the behavioral nature of the material promote using the proposed model in practical applications.

scholarly journals A Review on Structural Development of Magnetorheological Fluid Damper

2019 ◽  
Vol 2019 ◽  
pp. 1-33 ◽  
Author(s):  
Xianju Yuan ◽  
Tianyu Tian ◽  
Hongtao Ling ◽  
Tianyu Qiu ◽  
Huanli He
Keyword(s):  
Magnetorheological Fluid ◽  
Flow Mode ◽  
Structural Development ◽  
Market Selection ◽  
Mr Dampers ◽  
Developing Trend ◽  
Fluid Damper ◽  
Current Survey ◽  
Technical Features ◽  
Development Application

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.

Thermal and tribological characteristics of a disc-type magnetorheological brake operated by the shear mode

2018 ◽  
Vol 30 (5) ◽  
pp. 722-733 ◽  
Author(s):  
Wanli Song ◽  
Siyuan Wang ◽  
Seung-Bok Choi ◽  
Na Wang ◽  
Shichao Xiu
Keyword(s):  
Heat Dissipation ◽  
Operating Time ◽  
Wear Test ◽  
Magnetorheological Fluid ◽  
Operating Conditions ◽  
Tribological Characteristics ◽  
Transient Temperature ◽  
Shear Mode ◽  
Experimental Apparatus ◽  
Worn Surfaces

In this article, thermal characteristics and tribological properties of a disk-type magnetorheological fluid–based brake are investigated under various brake operating conditions such as different working gaps. In order to achieve this goal, a theoretical analysis of the heating and heat dissipation of the magnetorheological brake is first performed and then the transient temperature behaviors of the magnetorheological brake are investigated through simulation works associated with the finite element method. Subsequently, an experimental apparatus is established to measure temperature distributions of the magnetorheological brake as a function of the operating time. Thereafter, several heating and wear tests are conducted on the magnetorheological brake, and worn surfaces of the friction plates are observed using a scanning electron microscope to understand tribological characteristics of the magnetorheological brake. It is shown that the smaller working gap causes the higher temperature compared with the larger gap under the same magnitude of the input current applied to the magnetorheological fluid domain. This thermal behavior consequently results in the reduction of the braking torque. It is also demonstrated from the wear test that the small working gap significantly affects both wear and tribological characteristics showing the large ridges and deep grooves on the worn surfaces of the friction plate.

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