Seismic fragility of structures isolated by single concave sliding devices for different soil conditions

Castaldo, Paolo; Amendola, Guglielmo; Ripani, Marianela

doi:10.1007/s11803-018-0481-6

Cited by 10 publications

(4 citation statements)

References 39 publications

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“…[29,30] Like the TMDs, the efficiency of BI systems highly depends on the characteristics of the fixed-base superstructure, the control system (isolators in this case), and the input excitation. [17,21,[31][32][33][34][35][36][37] For example, Anajafi and Medina [21] showed that under narrowband excitations, the BI technique is effective only when the fixed-base superstructure is stiffer than the soil profile. In another studies, Matsagar and Jangid [32] and Kulkarni and Jangid [36] illustrated that for nonlinear BI systems, the response of the structure is significantly influenced by the hysteretic response of the isolator bearings.…”

Section: Robustness Of Common Passive Control Systemsmentioning

confidence: 99%

“…BI systems can decouple dynamic responses of a building from the horizontal components of ground excitations by interposing low‐horizontal stiffness bearings at the isolation interface . Like the TMDs, the efficiency of BI systems highly depends on the characteristics of the fixed‐base superstructure, the control system (isolators in this case), and the input excitation . For example, Anajafi and Medina showed that under narrowband excitations, the BI technique is effective only when the fixed‐base superstructure is stiffer than the soil profile.…”

Section: Introductionmentioning

confidence: 99%

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Robust design of a multi-floor isolation system

Anajafi

Medina

2018

Struct Control Health Monit

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Summary A multi‐floor isolation (MFI) technique can provide a building with inherent dynamic vibration suppressors through decoupling different portions of floors masses from the superstructure. This paper evaluates the seismic effectiveness and robustness of the MFI technique using a test‐bed 20‐story building. First, a parametric study approach is utilized to optimize MFI configurations with different isolated mass ratios (IMRs) and different number of isolated floor subsystems (IFSs). The response quantity to be optimized is the sum of root‐mean‐square interstory drift responses of the superstructure under a stochastic excitation. The sensitivity of the seismic performance of the optimally designed MFI configurations with respect to uncertainties in the properties of the superstructure, IFSs, and the ground excitation is evaluated. Simulation results illustrate that with the presence of these uncertainties, the effectiveness of the optimally designed MFI configurations with low and high IMRs (e.g., 5% and 90%) is significantly impaired, whereas configurations with intermediate IMRs (e.g., 50%) exhibit a relatively stable performance. Evaluation of the optimal placement of IFSs along the building height, when the number of IFSs is limited, reveals that placing the IFSs at top stories can lead to a near‐optimal system in terms of the spatial distribution of IFSs. A genetic algorithm is used to design a robust system for a selected configuration with top 10 IFSs and an IMR of 50%. The robust design is performed via minimizing the maximum deviation with respect to the design root‐mean‐square interstory drift response when the design parameters vary within a given uncertainty range.

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Section: Robustness Of Common Passive Control Systemsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Robust design of a multi-floor isolation system

Anajafi

Medina

2018

Struct Control Health Monit

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“…Laminated rubber bearings are the most commonly used due to their simple structure, stable performance, and favorable effect of seismic isolation 7–9 . FPS bearings are also extensively used because they can decouple the isolation period from the deck mass and perform well when subjected to large earthquake excitations 10,11 . The SIBs dissipate seismic energy primarily by doing work with restoring force, so their force–displacement relationship usually exhibits nonlinearity, which can be simulated by the bilinear hysteresis model or smooth hysteresis model such as the Bouc–Wen model 12,13 …”

Section: Introductionmentioning

confidence: 99%

The inter‐history iteration method for seismic response analysis of seismically isolated structures and its secondary development based on ABAQUS

Jia,

Li,

et al. 2023

Structural Design Tall Build

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SummaryIn seismic response analysis of seismically isolated structures (SISs), the nonlinearity is concentrated in the isolation layer while the upper structure behaves linearly, making SISs locally nonlinear systems. This paper proposed a novel seismic analysis method based on equivalent linearization (EL) and iterative solution for SISs. In this method, the equilibrium equations of an SIS are expressed by the second‐order ordinary differential equations of the structural system as well as the hysteretic force of seismic isolation bearings (SIBs). Based on EL theory, the linearized equilibrium equations of the overall system were reconstructed in which the EL parameters are derived theoretically. The inter‐history iteration (IHI) method was proposed to solve the linearized equation system and calculate the EL parameters in sequence iteratively for seismic response analysis of SISs, thus reducing computational cost without excessive loss of accuracy. In addition, the secondary development of the proposed method was programmed in ABAQUS for ease of engineering applications. Finally, the convergence and accuracy of the method were investigated through numerical simulation of an SIS case study. As the numerical investigation indicates, the proposed method considers the coupling between structural response and the EL parameters, achieving a high convergence rate and satisfactory solution accuracy. The ABAQUS secondary development program utilizes the powerful pre‐processor, post‐processor, and solvers of ABAQUS, making the IHI method more appropriate for engineering applications.

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“…Zhang Ruifa [6] used the multi-friction pendulum system (MFPS) to analyze the seismic response of an isolated vertical cylindrical large liquefied natural gas (LNG) storage tank, and proposed an ultra-large liquefied natural gas storage tank isolated by the MFPS tank. Castaldo P. [7] used a two-degree-of-freedom model considering the flexibility of the superstructure to analyze the seismic reliability of the friction pendulum system.…”

Section: Introductionmentioning

confidence: 99%

Friction pendulum test and parameter optimization for the vibration reduction of a 100 kv isolating switch

Wang¹,

Wang²,

Xu³

2021

J. vibroeng.

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An earthquake is a natural disaster with a high destructive force. According to previous history, a great many power grid facilities are damaged during the earthquake, and the damage to electrical equipment in substations are often very serious. This article takes the isolating switch in the substation as an experimental object. Firstly, the friction pendulum for vibration isolation is designed and manufactured according to the numerical simulation, and then the seismic test and vibration isolation test of the high voltage isolating switch are designed. The input waveforms and input acceleration intensities of the seismic test were designed experimentally. The test data of the isolating switch under the seismic condition and the vibration isolation condition with the friction pendulum vibration isolation system installed are mainly investigated. The measured acceleration of the top of the isolating switch bracket is used to compare and analyze the vibration isolation performance of the friction pendulum. Then, it can be seen that the friction pendulum system has the vibration isolation effects on the isolating switch. Especially, the isolation effects of friction pendulum are better when the acceleration intensity become higher. In order to obtain a better curvature radius and friction coefficient of the friction pendulum, based on the results of this test, the systematically numerical simulation tests for optimization on the friction pendulum vibration isolation system are conducted. The simulated top displacement of the isolating switch and the stress change of the root of the porcelain bottle were obtained. By comparing the vibration isolating performance of the friction pendulum under different parameters, numerical simulations show that the vibration isolation performance of the friction pendulum is better when the radius of curvature is 1200 mm and the friction coefficient is 0.04. The numerical results demonstrate that reasonable design of friction pendulum parameters can play a significant role in isolating vibration for power equipment.

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Seismic fragility of structures isolated by single concave sliding devices for different soil conditions

Cited by 10 publications

References 39 publications

Robust design of a multi-floor isolation system

Robust design of a multi-floor isolation system

The inter‐history iteration method for seismic response analysis of seismically isolated structures and its secondary development based on ABAQUS

Friction pendulum test and parameter optimization for the vibration reduction of a 100 kv isolating switch

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