Seismic Response of Multistory Buildings with Self-Centering Energy Dissipative Steel Braces

TLDR

The study investigates the seismic response of 2‑ to 16‑story steel‑framed buildings equipped with self‑centering energy‑dissipative braces. The authors modeled these buildings in Los Angeles, compared them with identical structures using buckling‑restrained braces, and performed incremental static and nonlinear dynamic analyses under ground‑motion ensembles at three hazard levels. SCED frames exhibited lower peak story drifts, reduced damage concentration, and smaller residual deformations than BRB frames, but showed higher floor acceleration peaks, and the results suggest that higher design seismic loads may be required for low‑rise SCED and BRB buildings to enhance collapse prevention.

Abstract

This paper examines the seismic response of 2-, 4-, 8-, 12-, and 16-story steel framed buildings with self-centering energy dissipative (SCED) bracing members. The structures are assumed to be located in Los Angeles, California. Identical buildings equipped with buckling restrained braces (BRB) are also studied for comparison purposes. Incremental static analysis and nonlinear dynamic analysis under ground motion ensembles corresponding to three hazard levels were performed. The SCED frames generally experienced smaller peak story drifts, less damage concentration over the building height, and smaller residual lateral deformations compared to the BRB system. Higher floor acceleration peaks were observed in the SCED frames due to the sharper transitions between elastic and inelastic response assumed in the analysis. The study also indicated that higher design seismic loads may be needed for low-rise SCED and BRB frames in order to improve their collapse prevention performance.