Investigation on the seismic fragility of steel eccentrically braced frames with vertical link using slotted bolt connection

Document Type : Original Article

Authors

1 MSc, Civil Engineering Department, Yazd University, Yazd, Iran

2 Assistant Professor, Civil Engineering Department, Yazd University, Yazd, Iran

10.22065/jsce.2024.422638.3253

Abstract

Passive control devices dissipate a significant amount of earthquake input energy and thus reduce the seismic demand for structural members. They are widely used in civil engineering due to their relatively low cost of installation, maintenance and simplicity. A slotted bolt connection type friction damper has the ability to provide more flexible performance due to frictional sliding during dynamic and static cyclic loads compared to the yielding dampers. The purpose of this research is to investigate the probabilistic approach and the seismic fragility of structures with slotted bolt connection using vertical link and compare it with the case without slotted bolt connection. In this study, by performing an incremental dynamic analysis with the help of 22 pairs of far-field earthquake records based on FEMA P-695, three types of 4, 8 and 12-story steel structures modeled in the OpenSEES software are investigated. Seismic fragility in different damage states, collapse margin ratios of the structure and also the possibility of collapse of the eccentrically bracing structure with the slotted bolted connection and without it have been discussed. The conducted research shows that the story velocity and base shear responses of the structure decreases when using slotted bolt connection. The results also indicate that the used friction damper leads to the improvement of seismic fragility and the increase of the collapse margin ratios, which can be mentioned as a 20% increase in the 12-story structure. In addition, the probability of structural failure has decreased by 35% on average compared to the eccentrically bracing structure without damper.

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Articles in Press, Accepted Manuscript
Available Online from 08 April 2024
  • Receive Date: 10 November 2023
  • Revise Date: 31 January 2024
  • Accept Date: 08 April 2024