Evaluation of seismic performance factors for dual steel SMF-SCBF systems using FEMA P695 methodology

Abstract

The present study evaluates the seismic performance factors of typical buildings with dual lateral force resisting system (LFRS) consisting of special moment frames (SMFs) combined with special concentrically braced frames (SCBFs) using FEMA P695 methodology. For this purpose, six building archetypes with 2-, 4-, 8-, 12-, 16- and 20-stories, in two short- and long-period performance groups were analyzed by the response spectrum method and designed based on the requirements of ASCE 7–16 and AISC 341–16. Validated nonlinear models were developed for each building in the OpenSees software platform. Then, the static and dynamic behavior of each building was investigated up to the collapse stage by nonlinear static analyses and nonlinear time history analyses under 44 far-field ground motions of FEMA P695. In this investigation, the peak and residual drift ratios, hysteresis behavior of the stories during the earthquake, collapse fragility curves, and seismic performance parameters (R, Ω, and Cd) were obtained and discussed. The results of nonlinear analyses demonstrated that code-compliant long period dual SMF-SCBFs (16 stories or higher) performed poorly and can be severely damaged in strong earthquakes.