Inelastic displacement ratios of fully self-centering controlled rocking systems subjected to near-source pulse-like ground motions

Rahgozar, Navid; Moghadam, Abdolreza S.; Aziminejad, Armin

doi:10.1016/j.engstruct.2015.11.030

Cited by 51 publications

(14 citation statements)

References 45 publications

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“…increase the inelastic displacement demand of structures with medium periods. More recently, Rahgozar et al [33] determined the IDRs for the selfcentering controlled rocking systems subjected to far-field and near-field pulse-like ground motions. It is found that the influences of pulse period, predominant period of ground motion, and modeling parameters on the IDRs are significant, whereas the effects of source-to-site distance, earthquake magnitude, and site classes are not much significant.…”

Section: The Peak Idrsmentioning

confidence: 99%

“…Most of the existing studies (except Rahgozar et al [33] ) are focused on the conventional structures exhibiting the bilinear elastoplastic hysteretic behavior (with zero or positive postyield stiffness). Therefore, they may not provide an accurate estimate of the IDR values for rocking systems exhibiting the self-centering type FS behavior.…”

Section: The Peak Idrsmentioning

confidence: 99%

“…For example, the use of relatively more detailed studies focusing explicitly on the evaluation of the IDRs for rocking systems (e.g., Rahgozer et al [33] ) may further improve the response predictions in future. The idea can also be developed further by extending its applicability to various other structural systems exhibiting different hysteretic responses.…”

Section: Figure 12mentioning

confidence: 99%

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Prediction of nonlinear seismic demands of high‐rise rocking wall structures using a simplified modal pushover analysis procedure

Najam

Qureshi

Warnitchai

et al. 2018

Structural Design Tall Build

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Summary This study presents a simplified analysis procedure for the convenient estimation of nonlinear seismic demands of high‐rise rocking wall structures. For this purpose, the displacement modification approach used in the nonlinear static procedure of ASCE/SEI 41‐13 is adopted. However, in the current study, this approach is extended to every significant vibration mode of the structure whereas the displacement modifying coefficients for different modes are calculated using the typical flag‐shaped hysteresis behavior of rocking walls. The parameters of this hysteresis behavior are selected to represent rocking walls with a practical range of energy dissipation capacity and postgap‐opening stiffness. The computed peak inelastic‐to‐elastic displacement ratios are presented as mean spectra, which can be used for the convenient estimation of pushover target displacement for every significant vibration mode. The accuracy of proposed procedure is examined using the seismic demands obtained from the nonlinear response history analysis of a 20‐story case study rocking wall structure. Furthermore, a modal decomposition technique is used to determine the individual modal seismic demands. The proposed procedure is found to predict both the combined and the individual modal demands with a reasonable accuracy and can serve as a convenient analysis option for the design and performance evaluation of high‐rise rocking wall systems.

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Section: The Peak Idrsmentioning

confidence: 99%

Section: The Peak Idrsmentioning

confidence: 99%

Section: Figure 12mentioning

confidence: 99%

See 1 more Smart Citation

Prediction of nonlinear seismic demands of high‐rise rocking wall structures using a simplified modal pushover analysis procedure

Najam

Qureshi

Warnitchai

et al. 2018

Structural Design Tall Build

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“…Since historical evidence shows that near-field pulse-like ground motions caused sever damages to nearby structures, in addition to the farfield ground motions, they are also considered. In recent years, inelastic displacement ratio of controlled rocking system subjected to near-fault (Rahgozar et al 2015) and the benefit of combining the post-tensioning and supplemental viscous damping in the near-source has been investigated (Tzimas et al 2016). The expected flag-shaped hysteretic curve of a CR-CSBF system, the load-reversal behavior of the fuse and hysteretic curve of PT elements is shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

Optimization of relative-span ratio in rocking steel braced dual-frames

Ghasemi

Nezamabadi

Moghadam

et al. 2020

Bull Earthquake Eng

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Controlled rocking concentrically steel braced frame (CR-CSBF) is an earthquake-resisting system that is effectively capable of reducing structural damage after earthquakes and causes resilience in the structure. Post-tensioning (PT) strands and fuse members are two important elements in CR-CBSFs to provide frame self-centering and energy dissipation, respectively. This study firstly purposes to evaluate the nonlinear response history analysis with five different relative-span ratios (A/B = 1.5, 2.0, 2.5, 3.0, 3.5). Various amounts of four parameters consist of the yield strength and modulus of elasticity of the fuse, the initial force of the PT cable, and the gravity load on the rocking column are also considered as design valuable factors in the analysis. Additionally, it is considered to involve the influence of frame height with 3-, 6-and 9-story and earthquake different characteristics. The second aim of the study is to investigate about optimizing the seismic response of CR-CSBFs, in order to determine the optimal A/B for each height of structures. In addition to previous valuable research, this study has taken a more innovational approach and aims to complement them. A statistical multi-objective optimization methodology is used to distinguish the design of the spanning ratio required to minimize the peak story drift ratio (PSD), peak roof displacement (PRD), peak roof acceleration (PRA) and peak base shear (PBS), which are considered seismic response demand factors. The results demonstrate that the optimal relative-span ratio or A/B for the three-story controlled rocking concentrically steel braced dual-frame is equal to 1.5, and for the six-and nine-story frames is equal to 3.5.

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“…Many researches on strengthening of moment resisting frames [14][15][16] and different procedures through base isolation [17][18][19] or energy dissipation systems [20][21][22][23] have been investigated for improving the seismic performance. Gerami and Abdollahzade [24] studied on Iranian design spectrum of IS 2800-05 and showed that spectral acceleration values of records having forward-directivity effects were at least two times of the corresponding values of IS 2800-05 at periods longer than 1 s.…”

Section: Introductionmentioning

confidence: 99%

Near-Fault Effects on RC Buildings’ Demand in Linear and Nonlinear Analyses

2017

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Abstract. Strong ground motions of near-fault earthquakes are mostly generated by forward-directivity effects. Forward-directivity effects develop energetic pulses particularly in horizontal velocity history of fault-normal component. The narrow-band nature of the pulses results in revealing at least two peaks on the response spectra and also increasing seismic demand especially for mid-rise and high-rise buildings.Iranian seismic code (IS 2800-14) presents the coefficient N, for considering near-fault effects. It seems that the N is not efficient for designing in near-fault zone. The accurate near-fault demands can be determined by using nonlinear response history analyses. In the present paper, two 3-D reinforced concrete framed structures (RC buildings) are designed according to ACI 2014 and IS 2800-14. Then, the demands are estimated by employing linear response history analysis (LRHA) and also nonlinear response history analysis (NRHA) under an ensemble of 11 near-fault ground motions. The results reveal that the design spectrum of IS 2800-14 is incompatible with near-fault spectra and underestimates demands in the long periods range. Further, implementation of LRHA using response modification factor (R u ) and deflection amplification factor (C d ) leads to insufficient inter-story drift ratios. Finally, the 2 influence of enhancing ductility is studied by determining ductility reduction factors for near-fault records.

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Inelastic displacement ratios of fully self-centering controlled rocking systems subjected to near-source pulse-like ground motions

Cited by 51 publications

References 45 publications

Prediction of nonlinear seismic demands of high‐rise rocking wall structures using a simplified modal pushover analysis procedure

Prediction of nonlinear seismic demands of high‐rise rocking wall structures using a simplified modal pushover analysis procedure

Optimization of relative-span ratio in rocking steel braced dual-frames

Near-Fault Effects on RC Buildings’ Demand in Linear and Nonlinear Analyses

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