A Comparative Evaluation of Semi-Active Control Algorithms for Real-Time Seismic Protection of Buildings via Magnetorheological Fluid Dampers

2021 ◽  
pp. 102795
Author(s):  
Ozge SAHIN ◽  
Nurettin Gokhan ADAR ◽  
Muaz Kemerli ◽  
Naci CAGLAR ◽  
Ismail Sahin ◽  
...  
Author(s):  
Eunchurn Park ◽  
Sung-Kyung Lee ◽  
Heon-Jae Lee ◽  
Seok-Joon Moon ◽  
Hyung-Jo Jung ◽  
...  

This study introduces the quantitative evaluation of the seismic performance of a building structure equipped with MR dampers by using real-time hybrid testing method (RT-HYTEM). A real-scaled 5-story building is used as the numerical substructure, and MR dampers corresponding to an experimental substructure is physically tested by using UTM. First, the force required to drive the displacement of the story, at which the MR damper is located, is measured from the load cell attached to UTM. Then, the measured force is returned to a control computer to calculate the response of the numerical substructure. Finally, the experimental substructure is excited by UTM with the calculated response of the numerical substructure. The RT-HYTEM implemented in this study is validated for that the real-time hybrid testing results obtained by application of sinusoidal and earthquake excitations and the corresponding analytical results obtained by using the Bouc-Wen model as the control force of the MR damper respect to input currents were in good agreement. Furthermore, semi-active control algorithms were applied to the MR damper. The comparison results of experimental and numerical responses demonstrated that using RT-HYTEM was more reasonable in semi-active devices such as MR dampers having strong nonlinearity.


Author(s):  
Shuo Wang ◽  
The Nguyen ◽  
Walter Anderson ◽  
Constantin Ciocanel ◽  
Mohammad Elahinia

Magnetorheological (MR) fluid mounts have their own advantages over the hydraulic mounts because they can provide extra damping and stiffness due to the MR effect. Many papers contribute to the control of MR fluid dampers, while very few papers focus on the control of MR mounts. This paper investigated skyhook control for a mixed mode MR fluid mount. The MR fluid mount can operate in two working modes: flow mode and squeeze mode. The skyhook control algorithms were developed and studied for the flow mode and squeeze mode separately and simultaneously. Simulation results show that the skyhook control can significantly reduce the resonance peak and achieve the lowest transmissibility in the whole working frequency range of the mount. When flow mode and squeeze mode are activated and controlled at the same time, the effect of squeeze mode is more obvious than that of the flow mode.


2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Wander Gustavo Rocha Vieira ◽  
Fred Nitzsche ◽  
Carlos De Marqui

In recent decades, semi-active control strategies have been investigated for vibration reduction. In general, these techniques provide enhanced control performance when compared to traditional passive techniques and lower energy consumption if compared to active control techniques. In semi-active concepts, vibration attenuation is achieved by modulating inertial, stiffness, or damping properties of a dynamic system. The smart spring is a mechanical device originally employed for the effective modulation of its stiffness through the use of semi-active control strategies. This device has been successfully tested to damp aeroelastic oscillations of fixed and rotary wings. In this paper, the modeling of the smart spring mechanism is presented and two semi-active control algorithms are employed to promote vibration reduction through enhanced damping effects. The first control technique is the smart-spring resetting (SSR), which resembles resetting control techniques developed for vibration reduction of civil structures as well as the piezoelectric synchronized switch damping on short (SSDS) technique. The second control algorithm is referred to as the smart-spring inversion (SSI), which presents some similarities with the synchronized switch damping (SSD) on inductor technique previously presented in the literature of electromechanically coupled systems. The effects of the SSR and SSI control algorithms on the free and forced responses of the smart-spring are investigated in time and frequency domains. An energy flow analysis is also presented in order to explain the enhanced damping behavior when the SSI control algorithm is employed.


Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley ◽  
Gregory J. Hiemenz

Novel semi-active vibration controllers are developed in this study for magnetorheological (MR) fluid-based vibration control systems, including: (1) a band-pass frequency shaped semi-active control algorithm, (2) a narrow-band frequency shaped semi-active control algorithm. These semi-active vibration control algorithms designed without resorting to the implementation of an active vibration control algorithms upon which is superposed the energy dissipation constraint. These new Frequency Shaped Semi-active Control (FSSC) algorithms require neither an accurate damper (or actuator) model, nor system identification of damper model parameters for determining control current input. In the design procedure for the FSSC algorithms, the semi-active MR damper is not treated as an active force producing actuator, but rather is treated in the design process as a semi-active dissipative device. The control signal from the FSSC algorithms is a control current, and not a control force as is typically done for active controllers. In this study, two FSSC algorithms are formulated and performance of each is assessed via simulation. Performance of the FSSC vibration controllers is evaluated using a single-degree-of-freedom (DOF) MR fluid-based engine mount system. To better understand the control characteristics and advantages of the two FSSC algorithms, the vibration mitigation performance of a semi-active skyhook control algorithm, which is the classical semi-active controller used in base excitation problems, is compared to the two FSSC algorithms.


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