Semi-active control of civil structures using magnetorheological dampers

2004 ◽  
Author(s):  
L. Alvarez ◽  
R. Jimenez
Keyword(s):  
Active Control ◽  
Magnetorheological Dampers ◽  
Civil Structures

scholarly journals Testing and isolation strategies for the vibrational hazards

2019 ◽  
Vol 39 (2) ◽  
pp. 124-131
Author(s):  
Huang Wei ◽  
Xu Jian ◽  
Zhang Tong-yi ◽  
Hu Ming-yi ◽  
Qin Jing-wei ◽  
...  
Keyword(s):  
Active Control ◽  
Control Strategies ◽  
Green Building ◽  
Power Equipment ◽  
Civil Structures ◽  
Severe Problem ◽  
Ground Floor ◽  
Initial Design ◽  
The Future ◽  
Water Pumps

In this paper, a test for investigating the vibrational hazards occurred in a modernized hospital was carried out, in which a lot of power equipment such as chilled water pumps and freezers, etc. were installed in the ground floor. The generated vibrations could be experienced on the upper floors including some medical precision room. Next, solation and active control strategies were proposed, and evidently the active control could improve the suppression a lot. This study illustrated that the great vibrational hazards could not be ignored anymore, and the followed resolution strategies for eliminating these vibrations seemed to be urgent. In tradition, the vibration isolations would not be involved in initial design for civil structures, but in fact this might lead to a severe problem to be addressed in the future, and this study could give inspiration for green building.

Semi-Active Control of Civil Structures With a One-Step-Ahead Prediction of the Seismic Response

2009 ◽  
Author(s):  
Kazuhiko Hiramoto ◽  
Taichi Matsuoka ◽  
Katsuaki Sunakoda ◽  
Akira Fukukita ◽  
Issei Yamazaki
Keyword(s):  
Seismic Response ◽  
Active Control ◽  
Passive Control ◽  
Inertial Force ◽  
Damping Coefficient ◽  
Superior Performance ◽  
Damping Force ◽  
Civil Structures ◽  
One Step ◽  
Command Signal

We propose a semi-active control of civil structures based on a one-step-ahead prediction of the seismic response. The vibration control device (VCD), which has been developed by authors, generates two types of resistance forces, i.e., a damping force proportional to the relative velocity and an inertial force proportional to the relative acceleration between two stories. The damping coefficient of the VCD can be changed with a command signal to an electric circuit connected to the VCD. In the present paper the command signal for changing the damping coefficient of each VCD is assumed to take two values, i.e., the command to take the maximum or minimum damping coefficient. The optimal command signal is selected from all candidates of command signals so that the Euclidean norm of the one-step-ahead predicted seismic response is minimized. As an example a semi-active control of a fifteen-story building with three VCDs is considered. The simulation results show that the proposed semi-active control achieves superior performance on vibration suppression compared with a passive control case where the damping coefficient of each VCD is fixed at its maximum value.

Mitigation of the seismic response of multi-span bridges using MR dampers: Experimental study of a new SMC-based controller

2016 ◽  
Vol 24 (1) ◽  
pp. 83-99 ◽  
Author(s):  
Omar El-Khoury ◽  
Chung Kim ◽  
Abdollah Shafieezadeh ◽  
Jee Eun Hur ◽  
Gwang Hee Heo
Keyword(s):  
Power Consumption ◽  
Active Control ◽  
Sliding Mode ◽  
Near Field ◽  
Magnetorheological Dampers ◽  
Adjacent Structures ◽  
Optimal Polynomial ◽  
Representative System ◽  
Reduced Power Consumption ◽  
Large Earthquakes

Pounding between adjacent structures has been a concern in multi-span bridges in recent earthquakes. In this paper, a pounding mitigation strategy using magnetorheological dampers is proposed, and its performance is tested for a three-span bridge using a series of shake-table experiments. A new semi-active control algorithm called SMC-OPC is developed that is based on a clipped sliding mode control (SMC) with sliding surfaces designed using an optimal polynomial control (OPC) approach. The control design uses a stochastically linearized model of the nonlinear bridge with passive components of the magnetorheological dampers embedded to achieve a more representative system characterization. Optimal weighting matrices for the optimal polynomial control are found through a genetic algorithm. The proposed method along with uncontrolled, passive-off, and passive-on cases are tested on shake-tables for several scaled near-field Kobe ground motion records. Although no pounding is observed in all control cases for small earthquakes, significant pounding occurs in the uncontrolled and passive-off systems under large earthquakes. For these ground motions, the performance of the semi-active controller converges to that of the passive-on case but with noticeably reduced power consumption. The study shows that the use of magnetorheological dampers between adjacent spans is very effective in mitigating critical bridge responses especially under large earthquakes. In addition, the proposed SMC-OPC semi-active control strategy enables achieving balance among multiple performance objectives with significantly reduced power consumption as compared to passive-on case.

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