Improving the torsional response of asymmetric buildings with self-centering controlled rocking steel braced frame system

2022 ◽  
pp. 136943322110509
Author(s):  
Maryam Hafezi ◽  
Armin Aziminejad ◽  
Mohammad Reza Mansoori ◽  
Mahmood Hosseini ◽  
Abdolreza Sarvghad Moghadam
Keyword(s):  
Center Of Mass ◽  
Asymmetric Structure ◽  
Maximum Displacement ◽  
Braced Frame ◽  
Asymmetric Buildings ◽  
Frame System ◽  
Strength And Stiffness ◽  
Ground Motion Records ◽  
Energy Absorbing ◽  
Steel Braced Frame

Self-centering controlled rocking steel braced-frame (SC-CR-SBF) is proposed as an earthquake-resistant system with low damage. Pre-stressed vertical strands provide a self-centering mechanism in the system and energy absorbing fuses restrict maximum displacement. Presence of asymmetry in structures can highlight the advantages of employing this structural system. Moreover, these days designing and constructing asymmetric and irregular structures is inevitable and as a result of architectural attractiveness and requirements of different functions of buildings, they are of great importance. Consequently, in these types of structures in order to minimize seismic responses, particular measures should be taken into consideration. Proper distribution of strength and stiffness throughout the plan of structures with self-centering systems can play a considerable role in resolving problems associated with asymmetry in these structures. In this study, the asymmetric buildings with 10% and 20% mass eccentricities and having different arrangements of centers were simulated. The models were analyzed under a set of 22 bidirectional far-field ground-motion records and corresponding responses of maximum roof drift, acceleration and rotation of the roof diaphragms of the structures with different arrangements of the center of mass, stiffness and strength were computed and studied. Results show that proper distribution of stiffness and strength throughout the plan of the structures with SC-CR-SBF system reduces the maximum roof drift as well as the rotation of the roof diaphragm. With appropriate arrangement of the centers, maximum drift response of the asymmetric structure decreases as much as roughly 20% and the ratio of the maximum drift response of the asymmetric structure to the response of the similar symmetric structure with the same overall stiffness and strength was 1.1. In other words, maximum drift response of the asymmetric structure with SC-CR-SBF system is acceptably close to the one for the symmetric building.

Ground Motion Intensity Measures for Rocking Building Systems

2017 ◽  
Vol 33 (4) ◽  
pp. 1533-1554 ◽  
Author(s):  
Mehrdad Shokrabadi ◽  
Henry V. Burton
Keyword(s):  
Ground Motion ◽  
Structural Response ◽  
Ground Acceleration ◽  
Intensity Measures ◽  
Braced Frame ◽  
Residual Drift ◽  
Engineering Demand Parameter ◽  
Frame System ◽  
Ground Motion Records ◽  
Steel Braced Frame

This paper investigates the effectiveness of various ground motion intensity measures (IMs) in estimating the structural response of two types of rocking systems: (a) a controlled rocking steel braced frame system with self-centering action and (b) a rocking spine system for reinforced concrete infill frames. The IMs are evaluated based on the dispersion in engineering demand parameter (EDP) predictions (efficiency) and the sensitivity of the conditional distributions of EDPs to the distributions of the magnitudes, distances and spectral shape parameter (ε) of ground motion records (sufficiency). The EDPs include maximum transient and residual story drifts and peak floor accelerations. The spectral acceleration averaged over a range of periods (Sa avg) is most effective for predicting transient and residual drift demands and peak ground acceleration (PGA) is generally the best predictor of peak floor accelerations. The proximity of the frequency range most affecting an EDP to that best reflected in an IM is found to be a good indicator of the performance of that IM.

scholarly journals Design of an earthquake resisting building using precast concrete cross-braced panels and incorporating energy absorbing devices

1979 ◽  
Vol 12 (4) ◽  
pp. 340-345
Author(s):  
C. D. Matthewson ◽  
R. A. Davey
Keyword(s):  
Precast Concrete ◽  
Office Building ◽  
Cost Estimates ◽  
Braced Frame ◽  
System A ◽  
Steel Members ◽  
Dynamic Analyses ◽  
Inherent Strength ◽  
Strength And Stiffness ◽  
Energy Absorbing

The design and the analysis of an irregular six storey office building are described. The building has an unconventional earthquake resisting system: a precast concrete cross-braced perimeter frame incorporating force-limiting devices (termed "inserts") in the form of enclosed axially yielding short steel members. A series of inelastic dynamic analyses indicates that the system very effectively combines the inherent strength and stiffness of the cross-braced frame with the energy-dissipating function of the yielding inserts. Cost estimates indicate that the system is a particularly economic one.

scholarly journals Proposed development of a damage-resisting Eccentrically Braced Frame with rotational active links

2011 ◽  
Vol 44 (2) ◽  
pp. 99-107 ◽  
Author(s):  
Mahbub H. Khan ◽  
G. Charles Clifton
Keyword(s):  
Time History ◽  
Damage Threshold ◽  
Integration Time ◽  
Maximum Displacement ◽  
Braced Frame ◽  
Axial Extension ◽  
Average Maximum ◽  
Strength And Stiffness ◽  
Ductility Capacity ◽  
Active Link

Eccentrically Braced Frames (EBFs) are widely used seismic-resisting systems, as they allow both strength and stiffness to be optimised while providing good ductility capacity. However, in theory they have a low damage threshold in severe earthquakes and post-earthquake repair of conventional EBFs will be difficult and expensive. This paper presents the Numerical Integration Time-History (NITH) analysis of two ten storey EBF buildings; one with a conventional active link and the other with a new form of low damage active link based on rotational sliding bolted plates. The low damage active link can be designed to allow rotation only, or to allow both rotation and axial extension. The conventional active link response in terms of displacement, rotation and inelastic demand was well within the range of the rotational active links under the records considered. The analysis shows that average maximum displacement of the building and rotation of the link for both the rotational and the rotational+extension active links was almost identical. The extension of the rotational active link permitting axial extension was less than 1.5 mm. Axial load demands on the collector beams and braces were similar in the case all three active links. It can be concluded from the analysis that the rotational active link with extension is not required, as the lateral extensions can be accommodated within the rotational plates with nominal clearances in the bolt holes to accommodate the lateral extension.

Research on Seismic Performance of the Steel-Braced Frame

2014 ◽  
Vol 540 ◽  
pp. 197-200
Author(s):  
Chang Jiao Hu ◽  
Xin Wu Wang
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
Braced Frame ◽  
Hysteretic Performance ◽  
Frame System ◽  
Steel Braced Frame

With the purpose of comprehending the seismic performance of steel-braced frame system better and more comprehensivly, the paper overviewed and summarized the hysteretic performance,ductility and energy dissipation performance of the steel-braced frame based on a large number of abroad documents.The force was on the seismic performance of steel-braced frame in different supporting forms and the insufficiency in the research.

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