A hybrid structural control system using a tuned liquid damper to reduce the wind induced motion of a base isolated structure

Love, J.S.; Tait, Michael J.; Toopchi‐Nezhad, Hamid

doi:10.1016/j.engstruct.2010.11.027

Cited by 58 publications

(33 citation statements)

References 21 publications

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“…Love et al [37] numerically modelled a base-isolated structure with SU-FREIs and a tuned liquid damper calibrated from experimental results. The SU-FREIs were represented by adapting the Bouc-Wen model from Chen and Ahmadi [38] with a fifth-order polynomial to better represent the softening and stiffening regimes.…”

Section: Stable Unbonded Fiber-reinforced Elastomeric Isolatorsmentioning

confidence: 99%

Structural and nonstructural performance of a seismically isolated building using stable unbonded fiber‐reinforced elastomeric isolators

Engelen

Konstantinidis

Tait

2015

Earthq Engng Struct Dyn

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Summary Stable unbonded fiber‐reinforced elastomeric isolators (SU‐FREIs) exhibit a characteristic horizontal softening and stiffening response, similar to other adaptive devices such as the triple friction pendulum and sliding systems with variable curvature. The transition between the softening and stiffening occurs at a displacement corresponding to a unique deformation known as full rollover. In this paper, the full rollover displacement of SU‐FREIs is altered by using modified support geometry (MSG), a geometric modification of the upper and lower supports applied to tailor the hysteresis loops of the isolator. Experimental results are used to calibrate a numerical model of a base‐isolated structure. The model demonstrates that the stiffening regime provides minimal restraint against displacements during events that meet or exceed the maximum considered earthquake. A parametric study revealed that the level of stiffening required to restrain displacements during large events is significant. This increase in stiffness is reflected in an increase in the response of the structure and light nonstructural components. Full rollover and MSG is considered advantageous to maintain horizontal stability and provide control over the stiffening of SU‐FREIs. Copyright © 2015 John Wiley & Sons, Ltd.

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Section: Stable Unbonded Fiber-reinforced Elastomeric Isolatorsmentioning

confidence: 99%

Structural and nonstructural performance of a seismically isolated building using stable unbonded fiber‐reinforced elastomeric isolators

Engelen

Konstantinidis

Tait

2015

Earthq Engng Struct Dyn

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“…However, a limitation of passive systems is in their restricted performance bandwidth, which typically makes them applicable to single types of hazard only. A solution is to employ highperformance control systems (HPCSs), which include semi-active [6][7][8], hybrid [9][10][11] and active damping systems [12][13][14], that offer significantly higher controllability due to their mechanical or chemical adaptive capability. HPCS can therefore be used to protect structures against multiple simultaneous or non-simultaneous types of hazards, termed multi-hazards.…”

Section: Introductionmentioning

confidence: 99%

Input space dependent controller for civil structures exposed to multi-hazard excitations

Cao

Laflamme

Hong

et al. 2018

Engineering Structures

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A challenge in the control of civil structures exposed to multiple types of hazards is in the tuning of control parameters to ensure a prescribed level of performance under substantially different excitation dynamics, which could be considered as largely uncertain. A solution is to leverage data driven control algorithms, which, in their adaptive formulation, can self-tune to uncertain environments. The authors have recently proposed a new type of data-driven controller, termed input space dependent controller (ISDC), that has the particularity to adapt its input space in real-time to identify key measurements that represent the essential dynamics of the system. Previous studies have focused on time delay formulations, where the adaptive control rule would use time delayed measurements as inputs. In this configuration, termed variable multi-delay controller (VMDC), the time delay itself was adaptive, which provided the input space dependence capabilities. However, the size, or embedding dimension, of the input space was kept constant. In this paper, the authors formulate and study a strategy to also have the embedding dimension vary, therefore providing full adaptive input space capabilities. This generalization of the ISDC algorithm will allow the controller to adapt to excitations with higher levels of chaos, such as a seismic event. The performance of ISDC under multi-hazard excitations is first investigated on a single-degree-of-freedom system and compared with the previously developed and demonstrated VMDC. Results show that the adaptive embedding dimension provides significantly enhanced mitigation performance. After, the ISDC performance is assessed on two benchmark buildings equipped with a semi-active friction device and subjected to non-simultaneous multihazard excitations (wind, blast and earthquake). Results are compared with a sliding mode controller, where the ISDC is shown to provide better mitigation capabilities. A B S T R A C TA challenge in the control of civil structures exposed to multiple types of hazards is in the tuning of control parameters to ensure a prescribed level of performance under substantially different excitation dynamics, which could be considered as largely uncertain. A solution is to leverage data driven control algorithms, which, in their adaptive formulation, can self-tune to uncertain environments. The authors have recently proposed a new type of data-driven controller, termed input space dependent controller (ISDC), that has the particularity to adapt its input space in real-time to identify key measurements that represent the essential dynamics of the system. Previous studies have focused on time delay formulations, where the adaptive control rule would use time delayed measurements as inputs. In this configuration, termed variable multi-delay controller (VMDC), the time delay itself was adaptive, which provided the input space dependence capabilities. However, the size, or embedding dimension, of the input space was kept constant. In this paper, the authors formulate a...

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“…Under wind excitation, Kareem (1997) showed that a TMD located at top of a base-isolated structure reduced the structural response. Love et al (2011) found that a system with tuned liquid damper and base isolation is effective in reducing the response of a base-isolated structure due to stationary random wind excitation by up to 30% to 45% depending on the magnitude of excitation. However, reductions are smaller for earthquake excitations; Palazzo and Petti (1999) and Taniguchi et al (2008) investigated the performance of a base-isolated system with TMDs added to control the displacement demand.…”

Section: Introductionmentioning

confidence: 99%

Enhanced performance through a dual isolation seismic protection system

Becker

Ezazi

2015

Struct. Design Tall Spec. Build.

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While base isolation successfully decreases the accelerations transmitted to a structure, a tradeoff is large unfavorable displacements in the isolation layer. This study investigates an innovative system, termed 'dual isolation', which applies two layers of isolation at the base and at mid-story to resolve this issue. A linear analytical solution for the equation of motion of the proposed system is developed on the basis of linear isolation theory. This creates a foundation to assess the behavior of various types of seismic protection systems and to select the damping and mass ratio that optimizes the performance of the proposed method. Dynamic response of an example dual isolated system to selected suites of ground motions is then examined. In addition to decreasing the displacement of the first isolation layer, the dual isolation system can greatly decrease floor accelerations of the upper portion of the building, further protecting building components and enhancing the comfort and safety of residents. displacement of the second floor, and when T 2 approaches T 1 , the mode shapes are approach 1 1 ! , and 1 À1 ! reduces the roof displacement of the system. This positive effect of increased mass ratio on the behavior of TMDs has been shown in other studies (Hoang et al., 2008;Taniguchi et al., 2008). Dual isolation systemFrom the examination of the theoretical results of mid-story isolation and base isolation with TMD, it is seen that the displacement demands on the second DOF decrease with larger values of γ and increase with larger T 2 , while the increase in T 2 reduces the displacement demand of the first DOF. These insights are used to select the preliminary parameters for the proposed dual isolation system. The same two DOF model shown in Figure 1 is used for a numerical response spectrum study. As a starting point, the mass ratio γ of the dual isolation system is chosen as 0.5, locating the second isolation layer at the mid height of the building. The period of the first isolation layer, T 1 , is chosen as 3.5 s, and the damping ratio of the first and second DOFs, β 1 and β 2 , were chosen as 15%. This dual isolation system was then analyzed using response spectrum analysis for a design basis earthquake (DBE), the spectrum for which is shown in Figure 2. The spectrum is defined for 10% probability of exceedance in 50 years downtown Seattle, WA, USA (47.60, À122.34), and soil type D (ASCE 07, 2010). The lateral story drifts found are presented in Figure 3, varying the period of the second isolation layer, T 2 . The left side of the graph represents the traditional base isolation system in which the natural period of the first DOF is much longer than the second DOF. As the period of the second DOF increases, the drift of the first DOF is reduced with the concession of increased drifts in the second DOF. This finding is in line with the theory explored in the previous section. Compared with the classic base isolation system, the participation factor of the first mode is decreased, reducing the first DOF's d...

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A hybrid structural control system using a tuned liquid damper to reduce the wind induced motion of a base isolated structure

Cited by 58 publications

References 21 publications

Structural and nonstructural performance of a seismically isolated building using stable unbonded fiber‐reinforced elastomeric isolators

Structural and nonstructural performance of a seismically isolated building using stable unbonded fiber‐reinforced elastomeric isolators

Input space dependent controller for civil structures exposed to multi-hazard excitations

Enhanced performance through a dual isolation seismic protection system

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