Experimental studies on magnetorheological brake containing plane, holed and slotted discs

2017 ◽  
Vol 69 (2) ◽  
pp. 116-122 ◽  
Author(s):  
Chiranjit Sarkar ◽  
Harish Hirani
Keyword(s):  
Experimental Studies ◽  
State Condition ◽  
Frictional Torque ◽  
Iron Particles ◽  
Low Friction ◽  
Mr Fluid ◽  
Content Type ◽  
Shear Rates ◽  
Mr Fluids ◽  
Braking Torque

Purpose This study aims to design an ideal magnetorheological (MR) brake that exerts negligible frictional torque in the off-state condition and controllable frictional torque in the on-state condition. Design/methodology/approach Silicone-based MR fluid, containing 9 per cent volume carbonyl iron particles, has been synthesized and used. The synthesized MR fluid is advantageous in maintaining low friction losses in off-state conditions. A magneto-rheometer has been utilized to characterize the off-state viscosity of the MR fluid at variable shear rates and shear stress of MR fluids at various magnetic fields. A mechanism to enhance the braking torque in the on-state condition has been designed and developed. An experimental test rig has been developed to capture the torque characteristics of the developed MR brakes. Three different designs of MR discs have been experimented under a magnetic field varying from 0 to 375 kA/m. Experimental results of braking torque under shear and compression modes have been presented. Findings Slotted disc MR brake gives much better torque performance. Originality/value The braking torque results motivate to use the slotted disc MR brake for high torque application.

Synthesis and field dependent shear stress evaluation of stable MR fluid for brake application

2017 ◽  
Vol 69 (5) ◽  
pp. 655-665 ◽  
Author(s):  
Lijesh K.P. ◽  
Deepak Kumar ◽  
Harish Hirani
Keyword(s):  
Shear Stress ◽  
Oleic Acid ◽  
Silicone Oil ◽  
Ammonium Hydroxide ◽  
Iron Particles ◽  
Mr Fluid ◽  
Content Type ◽  
Weight Percentage ◽  
Mr Fluids ◽  
Brake Application

Purpose The purpose of this paper is to report on the development of magnetorheological (MR) fluids, having high on-state shear stress/viscosity, low off-state shear stress/viscosity, good redispersibility and stable suspension of carbonyl iron particles, using tetramethyl ammonium hydroxide (TAH) and oleic acid. Design/methodology/approach MR fluids for use in brakes are synthesized using different weight percentages of silicone oil, TAH, oleic acid and iron particles. The effects of TAH and oleic acid are studied. Shear stress is measured as a function of magnetic field on a magneto-rheometer. The images of MR particles settling with time are presented. The test set-up used to evaluate the performance of the MR fluids synthesized for brake application is detailed. Finally, a significant improvement in the MR performance of brakes is reported. Findings The MR fluid having 0.25 Wt.% oleic acid showed low off-state viscosity/shear stress and high on-state viscosity/shear stress. A higher weight percentage of TAH in the MR fluid further reduced the low off-shear stress and increased the high on-state shear stress with better stability. Originality/value Improvement of MR brake performance by adding surfactants like TAH and oleic acid has been the subject matter of several studies in the past, but these studies used a fixed percentage of surfactants in MR fluids. In the present work, the optimum percentage of TAH and oleic acid for an improved braking performance is determined by varying their content in the MR fluid, which has not been reported in any other work thus far.

PREPARATION AND ABRASION PROPERTIES OF MAGNETO-RHEOLOGICAL FLUID OF DISPERSED SILICA-COATED IRON

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1121-1127 ◽  
Author(s):  
A. SHIBAYAMA ◽  
T. OTOMO ◽  
Y. AKAGAMI ◽  
K. SHIMADA ◽  
T. FUJITA
Keyword(s):  
Carbonyl Iron ◽  
Spherical Particles ◽  
Fluid Viscosity ◽  
Iron Particles ◽  
Mr Fluid ◽  
Abrasion Test ◽  
Silicon Oil ◽  
Mr Fluids ◽  
Transmission Oil ◽  
Magneto Rheological

In this study, a magneto-rheological fluid dispersed by silica-coated iron was developed and its properties such as fluid viscosity (shear stress or shear rate) and abrasion were investigated. The metallic iron coated by silica dispersed in magneto-rheological fluid was prepared by H 2 reducing of precipitated magnetite ( Fe 3 O 4). Then, the magneto-rheological fluid (MR fluid) for the seal was prepared with silica-coated iron or carbonyl iron (HQ type; diameter of 1.6-1.9 10-6m) and two solvent oils i.e. silicon oil (SH200cv, 10000cSt) and CVT oil (T-CVTF, automobile transmission oil). It was observed that the MR fluid viscosity of CVT oil with HQ particles is lower in every fluid condition. Furthermore, the surface roughness of polyvinyl plate after abrasion test for MR fluid with silica coated iron and CVT oil as solvent was higher compared to the other types of MR fluids. The results indicated that carbonyl iron (spherical particles) and silica-coated iron particles dispersed in silicon oil are feasible to be used where the low abrasion in mechanics is required.

RHEOLOGICAL PROPERTIES OF NOVEL MAGNETORHEOLOGICAL FLUIDS

2007 ◽  
Vol 21 (28n29) ◽  
pp. 4849-4857 ◽  
Author(s):  
S. MANTRIPRAGADA ◽  
X. WANG ◽  
F. GORDANINEJAD ◽  
B. HU ◽  
A. FUCHS
Keyword(s):  
Magnetic Field ◽  
Rheological Properties ◽  
Yield Stress ◽  
Parallel Plate ◽  
Magnetorheological Fluids ◽  
High Yield ◽  
Iron Particles ◽  
Shear Rates ◽  
Low Viscosity ◽  
Mr Fluids

The rheological properties of novel MR fluids are characterized using a parallel plate MR shear rheometer. In these MR fluids the surface of iron particles is coated with a polymer. The rheological properties are measured and compared at various magnetic field strengths, shear rates and strain amplitudes. It has been shown that these MR fluids exhibit stable and desirable rheological properties such as, low viscosity and high yield stress.

Rim Slip and Bead Fitment of Tires: Analysis and Design2

2006 ◽  
Vol 34 (1) ◽  
pp. 38-63 ◽  
Author(s):  
C. Lee
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Frictional Torque ◽  
Finite Element Analyses ◽  
Inflation Pressure ◽  
Contact Pressure Distribution ◽  
Design Modification ◽  
Iterative Design ◽  
Slip Resistance ◽  
Braking Torque

Abstract A tire slips circumferentially on the rim when subjected to a driving or braking torque greater than the maximum tire-rim frictional torque. The balance of the tire-rim assembly achieved with weight attachment at certain circumferential locations in tire mounting is then lost, and vibration or adverse effects on handling may result when the tire is rolled. Bead fitment refers to the fit between a tire and its rim, and in particular, to whether a gap exists between the two. Rim slip resistance, or the maximum tire-rim frictional torque, is the integral of the product of contact pressure, friction coefficient, and the distance to the wheel center over the entire tire-rim interface. Analytical solutions and finite element analyses were used to study the dependence of the contact pressure distribution on tire design and operating attributes such as mold ring profile, bead bundle construction and diameter, and inflation pressure, etc. The tire-rim contact pressure distribution consists of two parts. The pressure on the ledge and the flange, respectively, comes primarily from tire-rim interference and inflation. Relative contributions of the two to the total rim slip resistance vary with tire types, depending on the magnitudes of ledge interference and inflation pressure. Based on the analyses, general guidelines are established for bead design modification to improve rim slip resistance and mountability, and to reduce the sensitivity to manufacturing variability. An iterative design and analysis procedure is also developed to improve bead fitment.

Magnetorheological Damping of Fragment Barrier Suspension Systems

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Kwon Joong Son ◽  
Eric P. Fahrenthold
Keyword(s):  
Ballistic Performance ◽  
Mr Fluid ◽  
Suspension Systems ◽  
Mr Fluids ◽  
Ballistic Protection ◽  
Protection Systems ◽  
Fluid Damping ◽  
Magnetorheological Damping ◽  
Impact Experiments ◽  
Very High

Magnetorheological (MR) fluids, well established as components of a variety of suspension systems, may offer opportunities to improve the performance of fabric ballistic protection systems, which typically do not incorporate significant energy dissipation mechanisms. A series of ballistic impact experiments has been conducted to investigate the potential of MR fluid damped fabric suspension systems to improve upon current fabric barrier designs. The results indicate that for the simple fabric suspension systems tested, MR fluid damping does not improve upon the very high weight specific ballistic performance of state of the art aramid fibers.

scholarly journals Squeezing Force of the Magnetorheological Fluid Isolating Damper for Centrifugal Fan in Nuclear Power Plant

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Jin Huang ◽  
Ping Wang ◽  
Guochao Wang
Keyword(s):  
Nuclear Power ◽  
Theoretical Foundation ◽  
Fluid Dynamic ◽  
Flow Behavior ◽  
Magnetorheological Fluid ◽  
Centrifugal Fan ◽  
Parallel Channel ◽  
Mr Fluid ◽  
Mr Fluids ◽  
Control Devices

Magnetorheological (MR) disk-type isolating dampers are the semi-active control devices that use MR fluids to produce controllable squeezing force. In this paper, the analytical endeavor into the fluid dynamic modeling of an MR isolating damper is reported. The velocity and pressure distribution of an MR fluid operating in an axisymmetric squeeze model are analytically solved using a biviscosity constitutive model. Analytical solutions for the flow behavior of MR fluid flowing through the parallel channel are obtained. The equation for the squeezing force is derived to provide the theoretical foundation for the design of the isolating damper. The result shows that with the increase of the applied magnetic field strength, the squeezing force is increased.

Think about it – can portrayals of homosexuality in advertising prime consumer-perceived social connectedness and empathy?

2017 ◽  
Vol 51 (1) ◽  
pp. 82-98 ◽  
Author(s):  
Nina Åkestam ◽  
Sara Rosengren ◽  
Micael Dahlen
Keyword(s):  
Design Methodology ◽  
Social Connectedness ◽  
Experimental Studies ◽  
Social Effects ◽  
Attitudes Toward Homosexuality ◽  
Content Type ◽  
Advantages And Disadvantages ◽  
Thought Listing ◽  
Societal Level ◽  
Practical Implications

Purpose This paper aims to investigate whether portrayals of homosexuality in advertising can generate social effects in terms of consumer-perceived social connectedness and empathy. Design/methodology/approach In three experimental studies, the effects of advertising portrayals of homosexuality were compared to advertising portrayals of heterosexuality. Study 1 uses a thought-listing exercise to explore whether portrayals of homosexuality (vs heterosexuality) can evoke more other-related thoughts and whether such portrayals affect consumer-perceived social connectedness and empathy. Study 2 replicates the findings while introducing attitudes toward homosexuality as a boundary condition and measuring traditional advertising effects. Study 3 replicates the findings while controlling for gender, perceived similarity and targetedness. Findings The results show that portrayals of homosexuality in advertising can prime consumers to think about other people, thereby affecting them socially. In line with previous studies of portrayals of homosexuality in advertising, these effects are moderated by attitudes toward homosexuality. Research limitations/implications This paper adds to a growing body of literature on the potentially positive extended effects of advertising. They also challenge some of the previous findings regarding homosexuality in advertising. Practical implications The finding that portrayals of homosexuality in advertising can (at least, temporarily) affect consumers socially in terms of social connectedness and empathy should encourage marketers to explore the possibilities of creating advertising that benefits consumers and brands alike. Originality/value The paper challenges the idea that the extended effects of advertising have to be negative. By showing how portrayals of homosexuality can increase social connectedness and empathy, it adds to the discussion of the advantages and disadvantages of advertising on a societal level.

The interactive effect of insight and cuteness in driving purchase likelihood: a lay belief of creativity

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Felix Septianto ◽  
Rokhima Rostiani ◽  
Widya Paramita
Keyword(s):  
New Products ◽  
Interactive Effect ◽  
Experimental Studies ◽  
New Product ◽  
Underlying Mechanism ◽  
Content Type ◽  
Narrative Study ◽  
Managerial Implications ◽  
Purchase Likelihood

PurposeWhile new product introductions can potentially promote growth and benefit for brands, it remains unclear how marketers can develop effective communication strategies to increase the chance of success for new products. The present research investigates the role of cuteness in leveraging the effectiveness of a narrative emphasizing an insight versus an effort in this regard.Design/methodology/approachThis research presents two experimental studies. Study 1 examines the moderating role of cuteness on the likelihood of purchasing a new product featuring an insight-based (vs effort-based) narrative. Study 2 extends the findings of Study 1 using different stimuli and establishes the underlying mechanism.FindingsResults show that when a cuteness appeal is present, an insight-based (vs effort-based) narrative will lead to a higher purchase likelihood. However, these differences do not emerge when a cuteness appeal is absent (a control condition). Further, perceived brand creativeness will mediate this effect.Originality/valueThe findings of this research contribute to the literature on lay belief of creativity, cuteness, and product narrative, as well as managerial implications on how to promote new products.

Internal Organizational Measurement for Control of Magnetorheological Fluid Properties

2006 ◽  
Vol 129 (4) ◽  
pp. 423-428 ◽  
Author(s):  
John R. Lloyd ◽  
Miquel O. Hayesmichel ◽  
Clark J. Radcliffe
Keyword(s):  
Magnetic Field ◽  
Physical Properties ◽  
High Sensitivity ◽  
Time Varying ◽  
Measurable Effect ◽  
Mr Fluid ◽  
Fluid State ◽  
Mr Fluids ◽  
Fluid Properties ◽  
Field Excitation

Magnetorheological (MR) fluids change their physical properties when subjected to a magnetic field. As this change occurs, the specific values of the physical properties are a function of the fluid’s time-varying organization state. This results in a nonlinear, hysteretic, time-varying fluid property response to direct magnetic field excitation. Permeability, resistivity and permittivity changes of MR fluid were investigated and their suitability to indicate the organizational state of the fluid, and thus other transport properties, was determined. High sensitivity of permittivity and resistivity to particle organization and applied field was studied experimentally. The measurable effect of these material properties can be used to implement an MR fluid state sensor.

Toward an agreement on terminology of nuclear and subnuclear divisions of the motor thalamus

1997 ◽  
Vol 86 (4) ◽  
pp. 670-685 ◽  
Author(s):  
Giorgio Macchi ◽  
Edward G. Jones
Keyword(s):  
Nonhuman Primates ◽  
Experimental Studies ◽  
Medial Lemniscus ◽  
Nuclear Mass ◽  
Content Type ◽  
Human Thalamus ◽  
Human Motor ◽  
Motor Thalamus ◽  
Fine Print ◽  
Somatosensory Areas

✓ The nomenclature most commonly applied to the motor-related nuclei of the human thalamus differs substantially from that applied to the thalamus of other primates, from which most knowledge of input—output connections is derived. Knowledge of these connections in the human is a prerequisite for stereotactic neurosurgical approaches designed to alleviate movement disorders by the placement of lesions in specific nuclei. Transfer to humans of connectional information derived from experimental studies in nonhuman primates requires agreement about the equivalence of nuclei in the different species, and dialogue between experimentalists and neurosurgeons would be facilitated by the use of a common nomenclature. In this review, the authors compare the different nomenclatures and review the cyto- and chemoarchitecture of the nuclei in the anterolateral aspect of the ventral nuclear mass in humans and monkeys, suggest which nuclei are equivalent, and propose a common terminology. On this basis, it is possible to identify the nuclei of the human motor thalamus that transfer information from the substantia nigra, globus pallidus, cerebellum, and proprioceptive components of the medial lemniscus to prefrontal, premotor, motor, and somatosensory areas of the cerebral cortex. It also becomes possible to suggest the principal functional systems involved in stereotactically guided thalamotomies and the functional basis of the symptoms observed following ischemic lesions in different parts of the human thalamus.

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