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Indexed by:期刊论文

Date of Publication:2017-09-01

Journal:ADVANCED STEEL CONSTRUCTION

Included Journals:SCIE、EI

Volume:13

Issue:3

Page Number:273-292

ISSN No.:1816-112X

Key Words:Concentrically-braced frames; collapse limit state; incremental dynamic analysis; ductility demand spectrum; collapse ductility spectrum

Abstract:Steel concentrically-braced frames (CBFs) as seismic lateral force resisting systems have been widely used in seismic regions. The incremental dynamic analysis (IDA) is adopted to construct the collapse ductility spectrum for the CBF considering the P-Delta effect and sudden loss in strength and stiffness, which is physically more meaningful than existing baseline criteria. The design performance plot is constructed by newly combining the collapse ductility spectrum with ductility demand spectrum on the same figure, from which the threshold period and design ductility region for the frame are determined. A parametric study is conducted for the CBF over the full range of periods and parameters. The results show that the reserve capacity of the CBF contributes appreciably to collapse prevention, and the presented approach is more suitable for assessing the collapse of CBFs with dynamic instability. For moderate seismic regions, the threshold periods of the CBF determined by both the collapse ductility spectrum and existing baseline criteria are quite close. However, for high seismic regions, using the global drift angle limit may yield non-conservative results, since it fails to address the dynamic instability of CBFs with short periods.