Structural Control Effect and Performance of Structure Under Control of Impulse Semi-active Mass Control Mechanism

2020 ◽  
Author(s):  
Ming-Hsiang Shih ◽  
Wen-Pei Sung
Keyword(s):  
Structural Control ◽  
Control Mechanism ◽  
Control Effect ◽  
Active Mass ◽  
And Performance

Structural Control Considering Time Delay Effect

1985 ◽  
Vol 9 (4) ◽  
pp. 224-227 ◽  
Author(s):  
Mohamed Abdel-Rohman
Keyword(s):  
Time Delay ◽  
Active Control ◽  
Theoretical Consideration ◽  
Structural Control ◽  
Control Mechanism ◽  
Structural Response ◽  
Delay Effect ◽  
Numerical Example ◽  
Control Forces ◽  
Time Delay Effect

The time delay between measuring the structural response, and applying the designed active control forces may affect the controlled response of the structure if not taken into consideration. In this paper it is shown how to design the control forces to compensate for the delay effect. It is also shown that the time delay effect can be used as a criterion to judge the effectiveness of the proposed control mechanism. As an illustration of the theoretical consideration, a numerical example in which a tall building is controlled by means of active tendons is presented.

scholarly journals Seismic Resistance and Parametric Study of Building under Control of Impulsive Semi-Active Mass Damper

2021 ◽  
Vol 11 (6) ◽  
pp. 2468
Author(s):  
Ming-Hsiang Shih ◽  
Wen-Pei Sung
Keyword(s):  
Frequency Ratio ◽  
Efficiency Index ◽  
Reduction Ratio ◽  
Seismic Resistance ◽  
Control Effect ◽  
Active Mass ◽  
High Rise ◽  
Mass Damper ◽  
Active Mass Damper ◽  
External Forces

When high-rise buildings are shaken due to external forces, the facilities of the building can be damaged. A Tuned Mass Damper (TMD) can resolve this issue, but the seismic resistance of TMD is exhausted due to the detuning effect. The Impulsive Semi-Active Mass Damper (ISAMD) is proposed with fast coupling and decoupling at the active joint between the mass and structure to overcome the detuning effect. The seismic proof effects of a high-rise building with TMD and ISAMD were compared. The numerical analysis results indicate that: (1) the reduction ratio of the maximum roof displacement response and the mean square root of the displacement reduction ratio of the building with the ISAMD were higher than 30% and 60%, respectively; (2) the sensitivity of the efficiency index to the frequency ratio of the ISAMD was very low, and detuning did not occur in the building with the ISAMD; (3) to achieve stable seismic resistance of the ISAMD, its frequency ratio should be between 2 and 4; (4) the amount of displacement of the control mass block of the ISAMD can be reduced by enhancing the stiffness of the auxiliary spring of the ISAMD; and (5) the proposed ISAMD has a stable control effect, regardless of the earthquake distance.

Experimental Demonstration of Precision Control of a Deployable Optics Structure

2002 ◽  
Vol 124 (3) ◽  
pp. 441-450 ◽  
Author(s):  
R. Scott Erwin ◽  
Karl Schrader ◽  
Ruth L. Moser ◽  
Steven F. Griffin
Keyword(s):  
Control System ◽  
Structural Control ◽  
Level Control ◽  
Precision Control ◽  
Research Issues ◽  
Optical Surfaces ◽  
Point Tracking ◽  
High Bandwidth ◽  
And Performance ◽  
System 1

This paper presents the development, design, and implementation of a precision control system for a large, sparse-aperture space-deployable telescope testbed. Aspects of the testbed and laboratory environment relevant to nanometer-level control and performance objectives are provided. There are four main objectives of the control system: 1) reduction of natural resonances of the supporting structure, 2) rejection of tonal disturbances, 3) tip, tilt, and piston set-point tracking for optical surfaces, and 4) reduction in settling time of optical surfaces after an impulsive slew-type disturbance. The development of a three-input, three-output, high-bandwidth structural control system for the testbed is presented, and experimental data demonstrating that all objectives were attained is provided. The paper concludes with a discussion of the results and a description of research issues remaining to be addressed.

Polyolefin structural control using phenoxy-imine ligated group 4 transition metal complex catalysts

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Naoto Matsukawa ◽  
Sei-ichi Ishii ◽  
Rieko Furuyama ◽  
Junji Saito ◽  
Makoto Mitani ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Transition Metal ◽  
Metal Complex ◽  
Structural Control ◽  
Transition Metal Complex ◽  
Control Mechanism ◽  
Central Metal ◽  
Group 4 ◽  
Fi Catalyst ◽  
Metal Complex Catalysts

Abstract This paper describes the structural control of polyolefins achieved by using group 4 transition metal complex catalysts featuring a pair of phenoxy-imine chelate ligands (named FI catalysts). FI catalysts can produce very low to ultrahigh molecular weight polymers. For example, a Zr-FI catalyst bearing a cycloalkyl group on the imine-nitrogen with methylaluminoxane (MAO) activation is capable of selectively forming vinyl-terminated low molecular weight polyethylenes (Mw < 5000) whereas a Zr-FI catalyst with a triethylsilyl group ortho to the phenoxyoxygen can generate ethylene/propylene amorphous copolymers with ultra-high molecular weights (Mw > 10 000 000) when treated with iBu3Al / Ph3CB(C6F5)4. In addition, a Ti-FI catalyst, possessing an o-phenoxytrimethylsilyl group, with MAO can form highly syndiotactic polypropylenes ([rrrr] = 84%, Tm = 140°C) via a chainend control mechanism. Conversely, upon activation with iBu3Al / Ph3CB(C6F5)4, a Hf-FI catalyst with a tert-butyl group ortho to the phenoxy-oxygen is able to produce high molecular weight isotactic polypropylenes ([mm] = 69%, Tm = 124°C, Mw = 412 000) via a site control mechanism. Therefore, FI catalysts have shown the ability to create various polyolefin architectures by simple variation of the central metal, the ligand structure and the co-catalyst.

Active mass driver system as the first application of active structural control

2001 ◽  
Vol 30 (11) ◽  
pp. 1575-1595 ◽  
Author(s):  
Yoshiki Ikeda ◽  
Katsuyasu Sasaki ◽  
Mitsuo Sakamoto ◽  
Takuji Kobori
Keyword(s):  
Structural Control ◽  
Active Mass ◽  
Active Structural Control

Bio-Inspired Cell Concentration and Deformability Monitoring Chips

2007 ◽  
Vol 7 (11) ◽  
pp. 4214-4219 ◽  
Author(s):  
Young-Ho Cho ◽  
Sechan Youn ◽  
Dong Woo Lee
Keyword(s):  
Experimental Study ◽  
Control Mechanism ◽  
Cell Concentration ◽  
Biological Cell ◽  
High Integrability ◽  
Digital Signals ◽  
Cell Deformability ◽  
Destruction Mechanism ◽  
Biomedical Systems ◽  
And Performance

The paper presents a couple of biofluidic devices, whose functions are inspired from biological cell concentration and deformability monitoring functions. The cell concentration monitoring chip is inspired from RBC control mechanism in kidney, performing cell concentration monitoring functions. The cell deformability chip, inspired from selective RBC destruction mechanism in spleen, performs mechanical cell deformability monitoring functions. The structures and principles of the bio-inspired chips are presented and compared with those of the biological organs. The unique features and performance characteristics of the bio-inspired chips are analyzed and verified from experimental study. The bio-inspired cell concentration monitoring chips perform flow-rate insensitive concentration measurement, while the bio-inspired cell deformability monitoring chips achieve size-independent cell deformability measurement. Common advantages of the bio-inspired chips include simple structures, digital signals and high integrability, thus making them suitable for use in integrated digital biomedical systems.

Stimulus Sensitivity and Stimulus Intensity Control

1969 ◽  
Vol 28 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Julian Silverman ◽  
Monte Buchsbaum ◽  
Robert Henkin
Keyword(s):  
Stimulus Intensity ◽  
Control Mechanism ◽  
Sensory Threshold ◽  
Response Tendency ◽  
Low Intensity ◽  
Intensity Control ◽  
The Central Nervous System ◽  
And Performance ◽  
Light Flashes ◽  
Opposite Response

Previous research had suggested a relationship between averaged cortical evoked response (AER) characteristics and the perception of stimulus intensity. In this study a systematic relationship was hypothesized between AER characteristics and performance on traditional sensory threshold procedures. Averaged evoked responses to light flashes and performances on a battery of psychophysical tasks were measured in 20 normal volunteers. Ss with one AER pattern were sensitive to low-intensity stimulation; Ss with another AER pattern exhibited the opposite response tendency. These findings were interpreted in terms of a theoretical construct regarding a stimulus-intensity control mechanism in the central nervous system.

scholarly journals Inelastic Structural Control Based on MBC and FAM

2011 ◽  
Vol 2011 ◽  
pp. 1-18 ◽  
Author(s):  
Li Gang ◽  
Liu Qifeng ◽  
Li Hongnan
Keyword(s):  
Structural Control ◽  
Degrees Of Freedom ◽  
Complex Structure ◽  
Computational Method ◽  
New Method ◽  
Structural Vibration ◽  
Inelastic Behavior ◽  
Control Effect ◽  
Analogy Method ◽  
Inelastic Analysis

A complex structure has the characters of many degrees of freedom and intricate shape, especially inelastic behavior under strong external loadings. It is hard to apply the structural control technology to it. In this paper, a new method that combines the Market-Based Control (MBC) strategy and Force Analogy Method (FAM) is presented to analyze the inelastic behavior of structure with magnetorheological dampers. The MBC is used to reduce the structural vibration response, and FAM is proposed to perform the inelastic analysis. A numerical example is used to compare the control effect of the new method and LQR algorithm, which show the accuracy and efficiency of the proposed computational method.

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