Characterization of Ductility and Inelastic Displacement Demand in Base-Isolated Structures Considering Cyclic Degradation

Yaghmaei‐Sabegh, Saman; Safari, Sina; Abdolmohammad-Ghayouri, Karim

doi:10.1080/13632469.2017.1326415

Cited by 15 publications

(9 citation statements)

References 35 publications

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“…The first yielding in the superstructure pushover curve is assumed as a point of excursion into the nonlinear range (secondary slope of bilinear idealization). It has been clearly observed in previous studies that predicting the inelastic demand of structures is relatively correlated with the frequency content of earthquake excitation . Thus, earthquake records are carefully selected to highlight most features of NF and FF ground motions.…”

Section: Objective and Methodology Of Researchmentioning

confidence: 99%

“…With the aim of developing specific equations to estimate the inelastic displacement ratio (C 1 ) for BI structures, an efficient methodology is employed by using a 2DOF simplified model. While providing facilities of extensive parametric studies, [27][28][29][30][31][32][33][34][35][36] this model has been extensively used to investigate the performance of BI structures in recent years. Several parameters affect the inelastic responses of BI structures during seismic events.…”

Section: Objective and Methodology Of Researchmentioning

confidence: 99%

“…It has been clearly observed in previous studies that predicting the inelastic demand of structures is relatively correlated with the frequency content of earthquake excitation. 21,22,28 Thus, earthquake records are carefully selected to highlight most features of NF and FF ground motions. A p /V p ratio as a reliable parameter is used to characterize the frequency content of selected records.…”

Section: Objective and Methodology Of Researchmentioning

confidence: 99%

“…It is commonly agreed that BI structures experience higher ductility demand compared with counterpart FB buildings with a specific strength reduction ratio . Sayani and Ryan generated constant ductility spectra for FB and BI buildings and compared the performance objectives of the 2 systems.…”

Section: Introductionmentioning

confidence: 99%

“…1,4 It is commonly agreed that BI structures experience higher ductility demand compared with counterpart FB buildings with a specific strength reduction ratio. [27][28][29][30][31][32] Sayani and Ryan 33 generated constant ductility spectra for FB and BI buildings and compared the performance objectives of the 2 systems. They outlined that a general methodology could be extended to potentially fill a critical gap in the performance-based design of BI structures.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Estimation of inelastic displacement ratio for base‐isolated structures

Yaghmaei‐Sabegh

Safari

Ghayouri

2017

Earthq Engng Struct Dyn

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Summary This study develops a straightforward approximate method to estimate inelastic displacement ratio, C1 for base‐isolated structures subjected to near‐fault and far‐fault ground motions. Taking into account the inelastic behavior of isolator and superstructure, a 2 degrees of freedom model is employed. A total of 90 earthquake ground motions are selected and classified into different clusters according to the frequency content features of records represented by the peak ground acceleration to peak ground velocity ratio, Ap/Vp. A parametric study is conducted, and effective factors in C1 (i.e., fundamental vibration period of the superstructure, Ts; postyield stiffness ratio of the superstructure, αs; strength reduction ratio, R; vibration period of the isolator, Tb; strength of the isolator, Q; ratio of superstructure mass to total mass of the system, γm) are recognized. The results indicate that the practical range of C1 values could be expected for base‐isolated structures. Subsequently, effective parameters are included in simple predictive equations. Finally, the accuracy of the proposed approximate equations is evaluated and verified through error measurement, and comparisons are made in the analyses.

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Section: Objective and Methodology Of Researchmentioning

confidence: 99%

Section: Objective and Methodology Of Researchmentioning

confidence: 99%

Section: Objective and Methodology Of Researchmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Estimation of inelastic displacement ratio for base‐isolated structures

Yaghmaei‐Sabegh

Safari

Ghayouri

2017

Earthq Engng Struct Dyn

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Influence of ground motion characteristics on the heating effect of lead‐rubber bearings in base‐isolated structures

Xue,

Lu,

Yang

et al. 2024

Structural Design Tall Build

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Under earthquake excitations, the lead core inside the lead‐rubber bearing (LRB) generates heat, causing the mechanical degradation of LRBs. However, the heating effect is not commonly considered in the seismic analysis and design of base‐isolated structures with LRBs, which may underestimate the seismic response of structures, especially under ground motions with certain specific characteristics. This paper aims to reveal the influence of ground motion characteristics on the heating effect and provide useful references for the seismic analysis and design. In this study, the validated LRB model considering heating effect was employed in a base‐isolated building calibrated by testing data. Ground motion characteristics including amplitude, duration, and frequency content were separated by spectrally equivalent and different records. The results indicate that the rate and peak of the lead core temperature rise are strongly correlated to ground motion characteristics. Seismic responses ignoring the heating effect are underestimated, and this underestimate varies as the amplitude, duration, and frequency content change and reaches up to 60% in the studied case. Note that seismic responses of the isolation system are more affected by heating effects than the superstructure, and the duration shows a more significant influence on the stiffness degradation of LRBs than the frequency content. It is strongly recommended that the required duration of ground motions should be raised and the low stories of the superstructure should be reinforced for isolated structures with LRBs. The significant duration indicator DS5–95 is more reasonable than DS5–75 in the analysis of the heating effect.

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Constant ductility inelastic displacement ratio spectra of shape memory alloy-friction self-centering structures based on a hybrid model

Zhang

Shen²,

Wang³

2022

Bull Earthquake Eng

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Previous researches on the constant ductility inelastic displacement ratio spectra (𝐶 μ ) of self-centering structures have been conducted based on the typical flag-shaped self-centering (FS) model. However, the arising shape-memory-alloy-friction self-centering structures (SMAFSs) own their specialized force-displacement relationship different from the typical FS model. In this research, a hybrid force-displacement model composed of the typical FS model and Coulomb friction model is employed and an efficient calculating procedure is proposed to statistically investigate the 𝐶 μ of SMAFSs. Comparison with the 𝐶 μ of the typical FS system with similar selfcentering capacity shows that the 𝐶 μ of the SMAFS is significantly different from that of the typical FS system, which explains the necessity of employing the hybrid model for SMAFSs and the effects of the friction. The effects of seismic parameters and structural parameters on the 𝐶 μ of SMAFSs are investigated. Furthermore, the formula for estimating the 𝐶 μ of SMAFSs is proposed through statistical regression. This proposed formula could estimate the 𝐶 μ of SMAFSs and describe the effects of structural parameters more accurately. The research could provide a basis of estimating the 𝐶 μ of SMAFSs to obtain reliable seismic design results of the structures.

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Characterization of Ductility and Inelastic Displacement Demand in Base-Isolated Structures Considering Cyclic Degradation

Cited by 15 publications

References 35 publications

Estimation of inelastic displacement ratio for base‐isolated structures

Estimation of inelastic displacement ratio for base‐isolated structures

Influence of ground motion characteristics on the heating effect of lead‐rubber bearings in base‐isolated structures

Constant ductility inelastic displacement ratio spectra of shape memory alloy-friction self-centering structures based on a hybrid model

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