Multi-Scale Experimental Testing On Variable Stiffness And Damping Components For Semi-Active Structural Control

This article presents a novel rotary shock absorber which combines the abilities of variable stiffness and variable damping by assembling a set of two magnetorheological damping units, one of which being placed in series with a rubber spring. This allows the damping and stiffness to be controlled independently by the internal damping and the external damping units, respectively. A test bench was established to verify the variable stiffness and damping functionality. The experimental results for variable damping test, variable stiffness test and co-working test are presented. At the amplitude of 10° and the frequency 0.5 Hz, increases of 141.6% and 618.1% are obtained for damping and stiffness separately if the corresponding current increased from 0 to 1 A and from 0 to 2 A, respectively. A mathematical model is then developed and verified to predict the changing of the damping and stiffness. The test results and the simulated model confirm the feasibility of the shock absorber with the ability of varying damping and stiffness simultaneously.

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Parametric Study of Damping Characteristics of Magneto-Rheological Damper: Mathematical and Experimental Approach

Pollack Periodica ◽

10.1556/606.2020.15.3.4 ◽

2020 ◽

Vol 15 (3) ◽

pp. 37-48

Author(s):

Zubair Rashid Wani ◽

Manzoor Ahmad Tantray

Keyword(s):

Structural Control ◽

Research Work ◽

Testing Machine ◽

Input Voltage ◽

Damping Coefficient ◽

Control Technique ◽

Damping Force ◽

Active Devices ◽

Active Structural Control ◽

Magneto Rheological

The present research work is a part of a project was a semi-active structural control technique using magneto-rheological damper has to be performed. Magneto-rheological dampers are an innovative class of semi-active devices that mesh well with the demands and constraints of seismic applications; this includes having very low power requirements and adaptability. A small stroke magneto-rheological damper was mathematically simulated and experimentally tested. The damper was subjected to periodic excitations of different amplitudes and frequencies at varying voltage. The damper was mathematically modeled using parametric Modified Bouc-Wen model of magneto-rheological damper in MATLAB/SIMULINK and the parameters of the model were set as per the prototype available. The variation of mechanical properties of magneto-rheological damper like damping coefficient and damping force with a change in amplitude, frequency and voltage were experimentally verified on INSTRON 8800 testing machine. It was observed that damping force produced by the damper depended on the frequency as well, in addition to the input voltage and amplitude of the excitation. While the damping coefficient (c) is independent of the frequency of excitation it varies with the amplitude of excitation and input voltage. The variation of the damping coefficient with amplitude and input voltage is linear and quadratic respectively. More ever the mathematical model simulated in MATLAB was in agreement with the experimental results obtained.

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Modified LQG/LTR Control Methodology in Active Structural Control

Journal of Low Frequency Noise Vibration and Active Control ◽

10.1260/026309203322770347 ◽

2003 ◽

Vol 22 (2) ◽

pp. 97-108 ◽

Cited By ~ 1

Author(s):

Yan Sheng ◽

Chao Wang ◽

Ying Pan ◽

Xinhua Zhang

Keyword(s):

Structural Control ◽

Signal To Noise Ratio ◽

Open Loop ◽

Control Force ◽

Linear Quadratic ◽

Linear Quadratic Gaussian ◽

Control Approach ◽

Active Structural Control ◽

Loop Transfer Recovery ◽

Control Methodology

This paper presents a new active structural control design methodology comparing the conventional linear-quadratic-Gaussian synthesis with a loop-transfer-recovery (LQG/LTR) control approach for structures subjected to ground excitations. It results in an open-loop stable controller. Also the closed-loop stability can be guaranteed. More importantly, the value of the controller's gain required for a given degree of LTR is orders of magnitude less than what is required in the conventional LQG/LTR approach. Additionally, for the same value of gain, the proposed controller achieves a much better degree of recovery than the LQG/LTR-based controller. Once this controller is obtained, the problems of control force saturation are either eliminated or at least dampened, and the controller band-width is reduced and consequently the control signal to noise ratio at the input point of the dynamic system is increased. Finally, numerical examples illustrate the above advantages.

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Development of a novel variable stiffness and damping magnetorheological fluid damper

Smart Materials and Structures ◽

10.1088/0964-1726/24/8/085021 ◽

2015 ◽

Vol 24 (8) ◽

pp. 085021 ◽

Cited By ~ 30

Author(s):

Shuaishuai Sun ◽

Jian Yang ◽

Weihua Li ◽

Huaxia Deng ◽

Haiping Du ◽

...

Keyword(s):

Variable Stiffness ◽

Magnetorheological Fluid ◽

Magnetorheological Fluid Damper ◽

Fluid Damper ◽

Stiffness And Damping

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Modified sliding mode control of a seismic active mass damper system considering model uncertainties and input time delay

Journal of Vibration and Control ◽

10.1177/1077546316657477 ◽

2016 ◽

Vol 24 (6) ◽

pp. 1051-1064 ◽

Cited By ~ 10

Author(s):

Mehdi Soleymani ◽

Amir Hossein Abolmasoumi ◽

Hasanali Bahrami ◽

Arash Khalatbari-S ◽

Elham Khoshbin ◽

...

Keyword(s):

Structural Control ◽

Sliding Mode ◽

Test Structure ◽

Dynamic State ◽

Shake Table ◽

Model Uncertainties ◽

Actuator Dynamics ◽

Active Structural Control ◽

Mass Damper ◽

Active Mass Damper

Model uncertainties and actuator delays are two factors that degrade the performance of active structural control systems. A new robust control system is proposed for control of an active tuned mass damper (AMD) in a high-rise building. The controller comprises a two-loop sliding model controller in conjunction with a dynamic state predictor. The sliding model controller is responsible for model uncertainties and the state predictor compensates for the time delays due to actuator dynamics and process delay. A reduced model that is validated against experimental data was constructed and equipped with an electro-mechanical AMD system mounted on the top storey. The proposed controller was implemented in the test structure and its performance under seismic disturbances was simulated using a seismic shake table. Moreover, robustness of the proposed controller was examined via variation of the test structure parameters. The shake table test results reveal the effectiveness of the proposed controller at tackling the simulated disturbances in the presence of model uncertainties and input delay.

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