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.

Semiactive Control of Structural Vibrations

1993 ◽  
Author(s):  
W. N. Patten ◽  
H. C. Wu ◽  
W. Yan ◽  
R. L. Sack ◽  
C. C. Kuo ◽  
...  
Keyword(s):  
Active Control ◽  
Structural Control ◽  
Control Strategies ◽  
Structural Response ◽  
Semiactive Control ◽  
Hydraulic Actuator ◽  
Limit States ◽  
Loop Control ◽  
Mechanical Devices ◽  
Control Forces

Abstract Structural control can be used to mitigate dynamic structural response and prevent structures from reaching their limit states. Typical active vibration systems utilize large electric motors, and expensive hydraulic pumping equipment to provide force inputs to a structure during a dynamic event. The work here explores the effectiveness of low power, inexpensive semi-active control hardware to provide vibration attenuation, for structures. While there are a number of electro-mechanical devices that might provide semi-active control forces, the investigation here analyzed the use of an automatically adjustable hydraulic actuator (i.e., a shock absorber). The variation in damping characteristics is accomplished by using variable orificing. While semi-active hydraulic actuators are a relatively cheap means of providing smart damping for a structure, the development of effective closed loop control strategies for these devices is not a completely resolved issue. The paper develops a dynamic model of a semi-active actuator. Two inner loop controllers are then suggested, for the operation of the actuator. The control of a simple structure is then simulated. The paper closes with a comparison of the performances between a semi-active (clipped optimal) control and active control of a three story structure that is subject to an earthquake.

scholarly journals Time delay effect in a three coupled oscillator system of the physarum plasmodium

2000 ◽  
Vol 40 (supplement) ◽  
pp. S100
Author(s):  
A. Takamatsu ◽  
T. Fujii ◽  
I. Endo
Keyword(s):  
Time Delay ◽  
Delay Effect ◽  
Coupled Oscillator ◽  
Oscillator System ◽  
Time Delay Effect

scholarly journals Stability and Time-Delay Effect of Rainfall-induced Landslide Considering Air Entrapment

2021 ◽  
Author(s):  
Shixin Zhang ◽  
Li Li ◽  
Dongsheng Zhao ◽  
Bo Ni ◽  
Yue Qiang ◽  
...  
Keyword(s):  
Time Delay ◽  
Slope Stability ◽  
Heavy Rainfall ◽  
Parameter Analysis ◽  
Three Gorges Reservoir Area ◽  
Actual State ◽  
Air Entrapment ◽  
Delay Effect ◽  
Hydraulic Hysteresis ◽  
Time Delay Effect

Abstract Rainfall-induced landslide is a typical geological disaster in the Three Gorges reservoir area. The air entrapment in the pores of soils has a hindrance to the infiltration of the slope. It is mainly reflected in the hydraulic hysteresis after rainfall and the decrease of the slope anti-sliding force. A method considered the air entrapment of the closed gas in soil particles’ pores is developed to study the time-delay effect and slope stability under the rainfall process. The Green-Ampt infiltration model is used to obtain the explicit analytical solution of the slope infiltration considering air entrapment. Moreover, the relationship between the safety factor, the rainfall duration, and the depth of the wetting front under the three rainfall conditions (qrain=12, 26, 51 mm/h) is discussed. The results show that the air entrapment causes a significant time-delay effect of the landslide, and the hydraulic hysteresis is the strongest under the condition of heavy rainfall (qrain= 51mm/h). The time-delay effect lasts longer than low rainfall and heavy rainfall when the rainfall intensity (qrain= 26 mm/h) is slightly greater than saturated hydraulic conductivity Ks. Parameter analysis shows that when air entrapment is considered, the smaller the slope angle and the effective internal friction angle, the more significant the air entrapment has on the slope stability; the smaller the effective cohesion, the longer the air resistance lasts. Finally, the application of the Bay Area landslide is consistent with the actual state of the landslide.

Time-delay effect and compensation on direct output feedback controlled mass damper systems

2001 ◽  
Vol 31 (1) ◽  
pp. 121-137 ◽  
Author(s):  
S. Y. Chu ◽  
T. T. Soong ◽  
C. C. Lin ◽  
Y. Z. Chen
Keyword(s):  
Time Delay ◽  
Output Feedback ◽  
Delay Effect ◽  
Mass Damper ◽  
Time Delay Effect

Analysis of time delay effect on space power synthesis of optical dipole antenna

2013 ◽  
Vol 25 (6) ◽  
pp. 1504-1508
Author(s):  
邓琥 Deng Hu ◽  
尚丽平 Shang Liping ◽  
张阳 Zhang Yang ◽  
夏祖学 Xia Zuxue
Keyword(s):  
Time Delay ◽  
Dipole Antenna ◽  
Delay Effect ◽  
Time Delay Effect

Time Delay Effect on Social Interaction Dynamics

2015 ◽  
Author(s):  
Hiroyuki Iizuka ◽  
Sohtaroh Saitoh ◽  
Davide Marocco ◽  
Masahito Yamamoto
Keyword(s):  
Social Interaction ◽  
Time Delay ◽  
Delay Effect ◽  
Interaction Dynamics ◽  
Time Delay Effect
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