Evaluation of approximate methods for estimating residual drift demands in BRBFs

Asgarkhani, Neda; Yakhchalian, Mansoor; Mohebi, Benyamin

doi:10.1016/j.engstruct.2020.110849

Cited by 43 publications

(9 citation statements)

References 33 publications

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“…The yielding core length was assumed equal to 0.7 times the work point to work point length of the brace. The cross-section areas of the non-yielding segments were assumed equal to 5.0 times that of the brace core (Yakhchalian et al 2020;Asgarkhani et al 2020;Yakhchalian et al 2021). In addition, three elasticBeamColumn elements with negligible cross-section area and very high moment of inertia were added in parallel to the three corotTruss elements to prevent assumed for the beams and columns and ties; whereas for BRBs E0 = 0.12 and m = -0.458 were employed, according to the study by Uriz and Mahin (2008).…”

Section: Structures Considered and Modelingmentioning

confidence: 99%

Probabilistic seismic performance assessment of rocking buckling restrained braced frames

Soltani

Yakhchalian

Tavakoli

et al. 2023

Preprint

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One of the new lateral force resisting systems introduced to improve seismic performance of structures is rocking buckling restrained braced frame (RBRBF). This lateral force resisting system in each bay includes buckling restrained braces (BRBs) on one side and conventional braces on the other side, and vertical links between the upper ends of braces located in adjacent stories. In this system, conventional braces and adjacent columns are designed to remain elastic until near seismic collapse. In this paper, RBRBFs are designed according to a displacement-based design approach. Maximum interstory drift ratio (MIDR) and maximum residual interstory drift ratio (MRIDR) are among the most critical engineering demand parameters (EDPs) used for assessing the safety of structures after an earthquake. The primary aim of this study is to investigate the effects of utilizing RBRBFs on MIDR and MRIDR responses compared with buckling restrained braced frames (BRBFs). For this purpose, 4-, 8-, and 12-story structures with RBRBF and BRBF systems are considered, and their collapse capacity values and residual drift capacity values given different levels of MRIDR are computed using incremental dynamics analyses (IDAs). After computing the capacity values, the mean annual frequencies (MAFs) of collapse (λCol) and exceeding different MRIDR levels (λRD) are obtained. The results demonstrate that all RBRBFs have better collapse and residual drift performance than BRBFs. Based on these results, the use of RBRBFs dramatically reduces BRBF weaknesses including the concentration of damage in a single story and low post-yield stiffness.

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Section: Structures Considered and Modelingmentioning

confidence: 99%

Probabilistic seismic performance assessment of rocking buckling restrained braced frames

Soltani

Yakhchalian

Tavakoli

et al. 2023

Preprint

Self Cite

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“…The effectiveness of BRBFs has been proven in the technical literature by numerous experimental tests 9–13 and numerical simulations on steel 14–19 and concrete 20–22 buildings. Nevertheless, it has been widely acknowledged that BRBFs have low post‐yield stiffness, and their use may result in significant residual inter‐story drifts 23–26 . This is an undesirable feature of BRBFs that compromises their repairability and residual capacity after strong seismic events.…”

Section: Introductionmentioning

confidence: 99%

“…Nevertheless, it has been widely acknowledged that BRBFs have low post-yield stiffness, and their use may result in significant residual inter-story drifts. [23][24][25][26] This is an undesirable feature of BRBFs that compromises their repairability and residual capacity after strong seismic events. Various solutions have been suggested to overcome this shortcoming, the most important of which are: (1) using moment-resisting connections within BRBFs to create a dual system, [27][28][29][30][31] (2) development of BRBs with reduced core length, [32][33][34] and (3) employing self-centering technology in BRBFs.…”

Section: Introductionmentioning

confidence: 99%

Life cycle cost‐based optimization framework for seismic design and target safety quantification of dual steel buildings with buckling‐restrained braces

Amiri

Estekanchi

2023

Earthq Engng Struct Dyn

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This study proposes an efficient risk‐targeted framework for integrated optimal seismic design and quantifying target safety of Special Moment‐Resisting Frames (SMRFs) with Buckling‐Restrained Braces (BRBs) in the typical dual steel buildings. This framework provides an automated design procedure formulated as a constrained single‐objective optimization problem to achieve the minimum Life Cycle Cost (LCC) within the Particle Swarm Optimization (PSO) algorithm and can be the basis of current seismic codes for target safety calibration. LCC includes initial construction cost and lifetime seismic losses such as repair cost, repair time, and casualties. FEMA P‐58 methodology is employed for the LCC analysis of the building under possible earthquakes during its lifetime, which is able to take into account potential uncertainties in the hazard‐response‐damage‐loss relationship. An appropriate cost model is developed to estimate the initial and repair cost of the studied BRBs. Minimum requirements of ASCE and AISC codes are considered as design constraints. Nonlinear response history analysis through the Endurance Time (ET) method is utilized to estimate the structural responses versus seismic intensity. Three 4‐, 8‐, and 12‐story steel buildings with dual seismic force‐resisting system consisting of SMRF and BRB (called steel SMRF‐BRB) are selected as the case study. Each building is optimally designed with two approaches: (1) LCC‐based design within the proposed framework and (2) code‐based design to minimize initial construction cost. Comparison of optimized buildings with the two design approaches in terms of structural responses and seismic consequences demonstrates that fulfilling the minimum code requirements at a given seismic hazard level is not sufficient to minimize lifetime seismic losses of steel SMRF‐BRBs. This is because the optimal designs obtained from the code‐based approach are associated with damage concentration, irreparability, and high collapse probability, especially in seismic events more severe than the design level. The proposed LCC‐based approach provides useful information for improving the lifetime seismic performance of steel SMRF‐BRBs.

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“…BRBs dissipate energy by buckling and yielding in a controlled manner, reducing the force transmitted to the structure and enhancing its seismic performance [6]. Asgarkhani et al [7] used BRBs in reducing the damage caused by earthquakes in steel structures to ensure their safety and reliability after an earthquake. Yakhchalian et al [8,9] numerically modeled BRBs to assess the accuracy of the methods in predicting deflection amplification factor, which plays a key role on their actual behavior and capacity.…”

Section: Introductionmentioning

confidence: 99%

“…The use of FVDs and BRBs in retrofitting damaged buildings under seismic MA sequences is especially important as these devices can absorb energy and reduce the force transmitted to the structure during both the mainshock and aftershocks. Steel structures that use FVDs and BRBs have been shown to have significantly improved seismic performance compared to those without these devices [3,7]. The use of FVDs and BRBs reduces the stress and deformation on the structural members, preventing damage or collapse during seismic activity.…”

Section: Introductionmentioning

confidence: 99%

Retrofitting Damaged Buildings Under Seismic ‎mainshock-Aftershock Sequence

Mohebi,

Kazemi,

Asgarkhani

2023

Proceedings of the 8th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COM

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Mainshock-aftershock sequences are a common occurrence in areas with high seismic activity, and they can significantly increase the damage sustained by a building after the initial seismic event. During severe mainshock earthquake, there is a permanent deformation in the floor levels of the building that increases the risk of further damage and potential collapse in the aftershock earthquake. This research aims to introduce a computational method for retrofitting damaged buildings under seismic mainshock-aftershock sequences using Fluid Viscous Dampers (FVDs) and Buckling-Restrained Braces (BRBs). This retrofitting approach aims to mitigate further damage that may be caused by subsequent aftershocks. The use of computational methods enables engineers to accurately simulate the behavior of damaged structures under various seismic loads, which helps in the design and optimization of retrofitting techniques. Due to ability of FVDs and BRBs, two steel structures having four and six-story floor levels were selected to implement the computational method of retrofitting. The results of analysis confirmed that the mainshock-aftershock sequences can highly affect the performance of damaged buildings, and the proposed method can accurately model the damaged buildings with different pre-defined damage states.

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Evaluation of approximate methods for estimating residual drift demands in BRBFs

Cited by 43 publications

References 33 publications

Probabilistic seismic performance assessment of rocking buckling restrained braced frames

Probabilistic seismic performance assessment of rocking buckling restrained braced frames

Life cycle cost‐based optimization framework for seismic design and target safety quantification of dual steel buildings with buckling‐restrained braces

Retrofitting Damaged Buildings Under Seismic ‎mainshock-Aftershock Sequence

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