A new variable damping semiactive device for seismic response reduction of civil structures

Cundumi, Orlando; Suárez, Luis E.

doi:10.2140/jomms.2007.2.1639

Cited by 3 publications

(9 citation statements)

References 10 publications

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“…This was not within the scope of the present work. The effect of the time delay was investigated but it was not reported in the present article (see Cundumi, 2005). The effectiveness of the VDSA should be examined using more elaborate models of the structures.…”

Section: Discussionmentioning

confidence: 86%

“…This article presented an application of a variable damping mechanism to reduce the response of two adjacent structures. The system, referred to as the VDSA device, was originally conceived for application to single structures (Cundumi and Suárez, 2006, 2007). This article focused on the application of the VDSA system to reduce the response of two closely separated structures that are coupled by the device.…”

Section: Discussionmentioning

confidence: 99%

“…The procedure to define the control and response vectors in the modified algorithm [ Q v ] can be found in Cundumi (2005); here only the final results are reported. Considering first a Closed‐loop control , the variables { u ( t )} and { z ( t )} can be obtained as follows: where [ A 2 ]=[ Q ]+[ A v ][ Q v ][ A v ], [ A 3 ]=[ A v ][ Q v ][ S v ], [ T ] is the ( 2n × 2n ) modal matrix whose columns are the eigenvectors of [ A ], and { d ( t −Δt )} is a vector containing the response and control vectors and the excitation at time t −Δt , defined as: For the Closed‐open‐loop control case, { u ( t )} and { z ( t )} are calculated with the following equations: The solutions for the unknown quantities [ P ] (the Ricatti matrix) and { p ( t )} that represents the open‐loop control are: …”

Section: Theoretical Derivation Of the Modified Algorithms Qvmentioning

confidence: 99%

“…Although it is not reported in this article, the case of two coupled structures with opposite properties (i.e. rigid structures) was also studied (Cundumi, 2005). The level or response reduction achieved was similar and thus it is expected that structures with natural periods between the two limiting cases will have similar responses.…”

Section: Numerical Examplesmentioning

confidence: 99%

“…The effect of the time delay on the performance of the variable damping device was studied when it was applied to single and coupled structures (Cundumi, 2005). As expected, it was found that as the time delay increases, the performance of the system decreases, but the detrimental effect is not very large, at least for the range of time delays considered (up to five times the sampling time).…”

Section: Numerical Examplesmentioning

confidence: 99%

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Numerical Investigation of a Variable Damping Semiactive Device for the Mitigation of the Seismic Response of Adjacent Structures

Cundumi

Suárez

2008

Computer aided Civil Eng

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When two structures in close proximity and with different properties (heights, structural systems, materials) are subjected to a strong seismic ground motion there is the possibility that pounding between them may occur. The large impact loads induced by this phenomenon usually lead to catastrophic results. One way to overcome this effect is to couple the structures through elastic or damping elements. This article examines the use of a new variable damping device as a coupling element. The system, which is termed a variable damping semiactive (VDSA) device, consists of two dampers with constant parameters whose lower ends are attached to a common vertical rod whereas the upper ends are attached to the two structures. As the structures vibrate due to the ground motion, the lower end is moved up and down by means of an actuator. By changing the orientation of the dampers, the effective damping in the two structures can be changed in time in an appropriate manner to minimize the response. A new control law is used to calculate the optimal position of the dampers. The algorithm, referred to as Qv, is a variation of the Instantaneous Optimal Control and it is based on the minimization of a performance index J quadratic in the state vector, the control force vector, and a vector of absolute velocities measured at selected points. rithm includes a generalized LQR scheme where penalties are imposed on the state vector, on the control vector, and on the absolute velocity vector through three predefined matrices. A numerical simulation is used to verify the performance of the proposed protective system in reducing the seismic response to a series of historic earthquakes. The results show that the proposed device is able not only to eliminate the pounding effects but also to significantly reduce the response of the individual adjacent structures.

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Section: Discussionmentioning

confidence: 86%

Section: Discussionmentioning

confidence: 99%

Section: Theoretical Derivation Of the Modified Algorithms Qvmentioning

confidence: 99%

Section: Numerical Examplesmentioning

confidence: 99%

Section: Numerical Examplesmentioning

confidence: 99%

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Numerical Investigation of a Variable Damping Semiactive Device for the Mitigation of the Seismic Response of Adjacent Structures

Cundumi

Suárez

2008

Computer aided Civil Eng

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Improved semi-active control algorithm for hydraulic damper-based braced buildings

Azimi

Rasoulnia

Lin

et al. 2017

Struct Control Health Monit

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Summary Much research has been conducted on structural control systems to improve the seismic performance of structures under earthquakes and, ultimately, offer high performance‐resilient buildings beyond life risk mitigation. Among various structural control algorithms, semi‐active control strategies have been widely accepted for overcoming some limitations existed in either passive or active control systems, thereby leading to better structural performance over their counterparts. In this study, a new semi‐active control algorithm with minimum control parameters is developed to drive the hydraulic damper for effective control of the dynamic deformation of low‐ and high‐rise building structures under earthquake loadings. The new controller allows less input and computation for determining the damping coefficient of the hydraulic dampers while maintaining a higher performance. V‐braced buildings with three varying heights are used as prototypes to demonstrate the effectiveness of the proposed semi‐active damper. Two critical parameters, maximum drift and acceleration of stories, are defined for the performance criteria. The simulation results show that the developed semi‐active damper can significantly improve the seismic performance of the buildings in terms of controlled story drift and acceleration. By use of less input and reduced time delay effects, the proposed control system is comparable with those of existing semi‐active controllers. The findings in this study will help engineers to design control systems for seismic risk mitigation and effectively facilitate the performance‐based seismic design.

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Performance test and finite element modeling of variable damping viscous damper

Shi,

Fu,

et al. 2024

Soil Dynamics and Earthquake Engineering

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A new variable damping semiactive device for seismic response reduction of civil structures

Cited by 3 publications

References 10 publications

Numerical Investigation of a Variable Damping Semiactive Device for the Mitigation of the Seismic Response of Adjacent Structures

Numerical Investigation of a Variable Damping Semiactive Device for the Mitigation of the Seismic Response of Adjacent Structures

Improved semi-active control algorithm for hydraulic damper-based braced buildings

Performance test and finite element modeling of variable damping viscous damper

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