Smart hybrid isolation of a case study highway bridge exploiting seismic early warning information

Nuzzo, Iolanda; Caterino, Nicola; Maddaloni, Giuseppe; Occhiuzzi, Antonio

doi:10.1016/j.engstruct.2017.05.057

Cited by 9 publications

(4 citation statements)

References 26 publications

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“…Obviously, the number and strength capability of the MR devices obviously have to be defined according to the specific features of the case. A preliminary confirmation of such interpretation recently came from the satisfactory results achieved using the Italian regional controller applied to a real bridge located in southern Italy [62].…”

Section: Discussionmentioning

confidence: 73%

Exploring New Boundaries to Mitigate Structural Vibrations of Bridges in Seismic Regions: A Smart Passive Strategy

Maddaloni

Caterino

Nestovito

et al. 2016

Shock and Vibration

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The combined use of two emerging technologies in the field of seismic engineering is investigated. The first is a semiactive control, to reduce smartly the effects induced by earthquakes on structures. The second is the Seismic Early Warning System which allows an estimate of the Peak Ground Accelerations of an incoming earthquake. This paper proposes the exploitation of this information in the framework of a semiactive control strategy based on the use of magnetorheological (MR) dampers. The main idea consists of changing the MR dampers’ behaviour by the PGA estimated by the SEWS, to obtain the optimal seismic response of the structure. The control algorithm needed to drive the variable devices, according to the PGA estimate, is the core issue of the proposed strategy. It has been found that different characteristics of earthquakes that occur at different sites play a significant role in the definition of a control algorithm. Therefore, a design procedure for “regional” control algorithms has been performed. It is based on the results of several nonlinear dynamic simulations performed using natural earthquakes and on the use of a multicriteria decision-making procedure. The effectiveness of the proposed control strategy has been verified with reference to a highway bridge and to two specific worldwide seismic regions.

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Section: Discussionmentioning

confidence: 73%

Exploring New Boundaries to Mitigate Structural Vibrations of Bridges in Seismic Regions: A Smart Passive Strategy

Maddaloni

Caterino

Nestovito

et al. 2016

Shock and Vibration

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“…In some structural control applications, the MR dampers are calibrated only once in the triggering phase of an extraordinary load (e.g., earthquake [59]), and then they behave passively during the remaining part of the dynamic excitation. In these cases, the role of the structural monitoring is of secondary importance, if not null.…”

Section: The Role Of Frequency In Measurementmentioning

confidence: 99%

Variable Dampers to Mitigate Structural Demand to Wind Turbines: The Role of the Monitoring System Features for the Effectiveness of the Control Strategy

et al. 2020

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In the last decade, some researchers and professionals have been engaged in the study of methods and techniques that can build high wind turbines while containing construction costs within the limits of economic convenience. Among the most promising solutions is that of using innovative devices to mitigate the structural demand for the towers. The reduction in the stress demand in the foundation makes the strategy particularly interesting for the repowering of existing plants, where it is convenient not to demolish and rebuild the foundation, but rather to reuse the existing one for the new plant. A semi-active vibration control strategy, based on the adoption of controllable dissipative devices, is presented herein. The proposed technique requires the tower to be equipped with a measurement system suitable for the real time monitoring of structural response. Performing reliable high-frequency measurements of the horizontal displacement of points located at heights of tens of meters is not simple. With the purpose of assessing the efficiency and feasibility of Global Navigation Satellite System (GNSS)-based systems for the control of wind turbine structures, the proposed paper tries to investigate the characteristics and data processing techniques that are able to make the GNSS useful for such applications. Several numerical simulations were carried out with reference to a case-study wind turbine to quantitatively assess how the performance of the control system changes as the features of the monitoring system worsen, and finally to draw conclusions and suggestions for the minimum performance that monitoring devices must have for an effective reduction in structural demand.

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“…Back in 1993, Kobori et al suggested to control the isolation time period of the CSS by an active variable stiffness system. Similar concepts but based on semiactive control were adopted by Nagarajaiah et al, Li et al, Kataria et al, and Nuzzo et al, who augmented the control system by an early warning sensor system. In the studies, the researchers assumed a CSS with variable curvature to also change the isolation time period depending on the actual vibration state.…”

Section: Introductionmentioning

confidence: 99%

“…The investigations are a testimony of the need to understand the role of damping in seismic isolators and the controlled isolators described in Kobori et al, Nagarajaiah and Sahasrabudhe, Li and Ou, Kataria and Jangid, and Nuzzo et al demonstrate the strong impact of variable isolator stiffness on isolation. This paper is therefore concerned with the optimization and assessment of CSS with different damping mechanisms and controllable stiffness to identify isolator types that strongly reduce structural accelerations without leading to inacceptable large isolator displacements.…”

Section: Introductionmentioning

confidence: 99%

Curved surface sliders with friction damping, linear viscous damping, bow tie friction damping, and semiactively controlled properties

Weber

Distl

Meier

et al. 2018

Struct Control Health Monit

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Summary This paper investigates the isolation performance of curved surface sliders (CSSs) with different damping mechanisms. The following passive damping mechanisms are considered: passive friction damping as commonly present in CSSs, linear viscous damping as linear damping mechanism, and bow tie friction as adaptive, that is, position‐dependent, but passive approach; CSSs with adaptive behaviour based on different sliding regimes are not considered. From the field of CSSs with semiactive dampers, two control strategies are considered: amplitude proportional friction damping aiming at linearizing the friction damping over one cycle and semiactively controlled damping and stiffness properties to enhance the decoupling between ground and structure by the emulation of zero dynamic stiffness. The CSSs under consideration are assessed in terms of peak structural acceleration, peak CSS horizontal force and displacement, and recentring error as function of peak ground acceleration (PGA) of the accelerograms. The results demonstrate that (a) friction damping can be optimized at one PGA only due to its nonlinearity, (b) the optimization of linear viscous damping does not depend on PGA, (c) optimized bow tie friction improves the isolation at low PGA while the isolation at medium to high PGAs worsens, (d) optimized amplitude proportional friction damping does not improve the isolation compared with optimized linear viscous damping, and (e) zero dynamic stiffness is preferably emulated only for a certain range of CSS relative motion amplitude to keep the recentring error within acceptable limits.

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Smart hybrid isolation of a case study highway bridge exploiting seismic early warning information

Cited by 9 publications

References 26 publications

Exploring New Boundaries to Mitigate Structural Vibrations of Bridges in Seismic Regions: A Smart Passive Strategy

Exploring New Boundaries to Mitigate Structural Vibrations of Bridges in Seismic Regions: A Smart Passive Strategy

Variable Dampers to Mitigate Structural Demand to Wind Turbines: The Role of the Monitoring System Features for the Effectiveness of the Control Strategy

Curved surface sliders with friction damping, linear viscous damping, bow tie friction damping, and semiactively controlled properties

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