Magnetorheological Damper for Performance Enhancement Against Seismic Forces

Abstract Due to low power consumption and fast response, magnetorheological (MR) dampers are widely used in various engineering applications. To enhance the performances, efforts have been made to increase the field dependent force with the same power consumption. However, the fluid viscous force is also increased significantly, which is undesirable in practical use. To tackle this problem, the focus of this paper is to design and test a new MR damper with micro-grooves for performance enhancement. First, the detailed design of the proposed MR damper is provided. A prototype of the new MR damper is fabricated. Silicon steel circular rings with thickness of 0.25 mm are installed around the damper piston to form two-layer micro-grooves. Experimental results of the two MR dampers without and with micro-grooves are then compared. The advantages of MR damper with micro-grooves over the one without micro-grooves are validated. The damping force and controllable force range of MR damper with micro-grooves are larger than the one without micro-grooves. When designing MR damper, making micro-grooves can also decrease the increment of fluid viscous force while keeping the same increase of field dependent force. With micro-grooves, the field dependent force is increased by 92.7% with the same power consumption, while the fluid viscous force is increased by 43%.

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Development and simulation of magnetorheological damper for segment erector vibration control

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-2018-0131 ◽

2019 ◽

Vol 43 (2) ◽

pp. 237-247 ◽

Cited By ~ 2

Author(s):

Bo Yang ◽

Ao Zhang ◽

Yan Bai ◽

Kuo Zhang ◽

He Li

Keyword(s):

Performance Enhancement ◽

Fuzzy Controller ◽

Random Excitation ◽

Magnetorheological Damper ◽

Magnetorheological Dampers ◽

Linear Control Theory ◽

Nonlinear Design ◽

Highly Nonlinear ◽

Takagi Sugeno ◽

Segment Erector

In this paper, magnetorheological dampers are applied to a segment erector to replace passive vibration dampers. Because magnetorheological damper dynamics are highly nonlinear, design of a direct control system is impossible. To apply linear control theory directly to design the magnetorheological damper controller, the Takagi–Sugeno fuzzy model analytically represents the segment erector model. In addition, a disturbance observer based on a Takagi–Sugeno fuzzy controller is proposed for this system. Both simulations and experiments validate the performance enhancement and stability of the controller. The results show that the acceleration of the segment erector was reduced by 59.6% and 32.1% in oblique wave excitation and random excitation, respectively, compared to a conventional passive damper. The proposed fuzzy controller and magnetorheological dampers have great potential in practical applications because they can significantly improve the performance of a segment erector.

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Mindful sport performance enhancement: Mental training for athletes and coaches.

10.1037/0000048-000 ◽

2018 ◽

Cited By ~ 12

Author(s):

Keith A. Kaufman ◽

Carol R. Glass ◽

Timothy R. Pineau

Keyword(s):

Performance Enhancement ◽

Sport Performance ◽

Mental Training

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Performance Enhancement, Creativity and Mental Training

PsycEXTRA Dataset ◽

10.1037/e579872013-105 ◽

2003 ◽

Author(s):

M. Bar-Eli ◽

O. Lowengart ◽

J. Goldberg ◽

S. Epstein ◽

R. D. Fosbury

Keyword(s):

Performance Enhancement ◽

Mental Training

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Effective performance improvement of organic thin film transistors with multi-layer modifications

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200138 ◽

2020 ◽

Vol 91 (3) ◽

pp. 30201

Author(s):

Hang Yu ◽

Jianlin Zhou ◽

Yuanyuan Hao ◽

Yao Ni

Keyword(s):

Thin Film ◽

Thin Film Transistors ◽

Performance Enhancement ◽

Organic Thin Film Transistors ◽

Electrical Performance ◽

Hole Injection ◽

Organic Thin Film ◽

Effective Performance ◽

Significant Performance ◽

P Type

Organic thin film transistors (OTFTs) based on dioctylbenzothienobenzothiophene (C8BTBT) and copper (Cu) electrodes were fabricated. For improving the electrical performance of the original devices, the different modifications were attempted to insert in three different positions including semiconductor/electrode interface, semiconductor bulk inside and semiconductor/insulator interface. In detail, 4,4′,4′′-tris[3-methylpheny(phenyl)amino] triphenylamine (m-MTDATA) was applied between C8BTBTand Cu electrodes as hole injection layer (HIL). Moreover, the fluorinated copper phthalo-cyanine (F16CuPc) was inserted in C8BTBT/SiO2 interface to form F16CuPc/C8BTBT heterojunction or C8BTBT bulk to form C8BTBT/F16CuPc/C8BTBT sandwich configuration. Our experiment shows that, the sandwich structured OTFTs have a significant performance enhancement when appropriate thickness modification is chosen, comparing with original C8BTBT devices. Then, even the low work function metal Cu was applied, a normal p-type operate-mode C8BTBT-OTFT with mobility as high as 2.56 cm2/Vs has been fabricated.

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Performance enhancement of normal contact ratio gearing system through correction factor

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.13.3.2019.03.0429 ◽

2019 ◽

Vol 13 (3) ◽

pp. 5242-5258

Author(s):

R. Ravivarman ◽

K. Palaniradja ◽

R. Prabhu Sekar

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Correction Factor ◽

Bending Strength ◽

Performance Enhancement ◽

Transmission Ratio ◽

Contact Ratio ◽

Element Analysis ◽

Normal Contact ◽

Root Region

As lined, higher transmission ratio drives system will have uneven stresses in the root region of the pinion and wheel. To enrich this agility of uneven stresses in normal-contact ratio (NCR) gearing system, an enhanced system is desirable to be industrialized. To attain this objective, it is proposed to put on the idea of modifying the correction factor in such a manner that the bending strength of the gearing system is improved. In this work, the correction factor is modified in such a way that the stress in the root region is equalized between the pinion and wheel. This equalization of stresses is carried out by providing a correction factor in three circumstances: in pinion; wheel and both the pinion and the wheel. Henceforth performances of this S+, S0 and S- drives are evaluated in finite element analysis (FEA) and compared for balanced root stresses in parallel shaft spur gearing systems. It is seen that the outcomes gained from the modified drive have enhanced performance than the standard drive.

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