Stochastic optimisation of buckling restrained braced frames under seismic loading

Jiaqi Xu, Gaston A. Fermandois, Billie F. Spencer, Xilin Lu

Research output: Contribution to journalArticlepeer-review

Abstract

A stochastic optimisation procedure is proposed for the design of low- and mid-rise buckling restrained braced frames subject to seismic loading. The seismic excitation is represented as a zero-mean nonstationary filtered white noise. The Bouc–Wen model is chosen to represent the hysteretic behaviour of the buckling restrained braces. The equivalent linearisation method is employed to determine the second-order statistics of structural responses from the non-linear system. Three seismic intensity levels are considered in this study, which are associated to earthquakes with different probability of occurrence during the building’s lifecycle. It was observed that the optimal design that minimises the maximum ductility demand produces a more uniform distribution of energy dissipation and avoids soft-storey mechanisms; therefore, this design objective is considered to be a more reasonable optimisation objective for the design of buckling restrained braced frames. For higher rise structures, buckling restrained braces may experience over-dimensioning in the top stories, which means that dissipation will not occur. Thus, an upper bound constraint for the stiffness design of the buckling restrained braces is taken into account.

Original languageEnglish (US)
Pages (from-to)1386-1401
Number of pages16
JournalStructure and Infrastructure Engineering
Volume14
Issue number10
DOIs
StatePublished - Oct 3 2018

Keywords

  • Structural optimisation
  • buckling restrained braced frames
  • hysteretic behaviour
  • seismic response
  • stochastic seismic loading

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Safety, Risk, Reliability and Quality
  • Geotechnical Engineering and Engineering Geology
  • Ocean Engineering
  • Mechanical Engineering

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