TY - JOUR
T1 - Assessment of buckling-restrained braced frame reliability using an experimental limit-state model and stochastic dynamic analysis
AU - Andrews, Blake M.
AU - Song, Junho
AU - Fahnestock, Larry A.
N1 - Funding for the first author was provided by the Dwight David Eisenhower Transportation Fellowship Program, administered by the National Highway Institute, an organization of the Federal Highway Administration (FHWA), under FHWA Grant No. DDEGRD-06-X-00408.
Correspondence to: Larry A. Fahnestock, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, IL, 61801, USA Tel: (217) 265-0211; Fax (217) 265-8040 E-mail: [email protected] †Engineer; ‡Assistant Professor Supported by: Federal Highway Administration Under Grant No. DDEGRD-06-X-00408 Received February 5, 2009; Accepted March 22, 2009
PY - 2009/9
Y1 - 2009/9
N2 - Buckling-restrained braces (BRBs) have recently become popular in the United States for use as primary members of seismic lateral-force-resisting systems. A BRB is a steel brace that does not buckle in compression but instead yields in both tension and compression. Although design guidelines for BRB applications have been developed, systematic procedures for assessing performance and quantifying reliability are still needed. This paper presents an analytical framework for assessing buckling-restrained braced frame (BRBF) reliability when subjected to seismic loads. This framework efficiently quantifies the risk of BRB failure due to low-cycle fatigue fracture of the BRB core. The procedure includes a series of components that: (1) quantify BRB demand in terms of BRB core deformation histories generated through stochastic dynamic analyses; (2) quantify the limit-state of a BRB in terms of its remaining cumulative plastic ductility capacity based on an experimental database; and (3) evaluate the probability of BRB failure, given the quantified demand and capacity, through structural reliability analyses. Parametric studies were conducted to investigate the effects of the seismic load, and characteristics of the BRB and BRBF on the probability of brace failure. In addition, fragility curves (i.e., conditional probabilities of brace failure given ground shaking intensity parameters) were created by the proposed framework. While the framework presented in this paper is applied to the assessment of BRBFs, the modular nature of the framework components allows for application to other structural components and systems.
AB - Buckling-restrained braces (BRBs) have recently become popular in the United States for use as primary members of seismic lateral-force-resisting systems. A BRB is a steel brace that does not buckle in compression but instead yields in both tension and compression. Although design guidelines for BRB applications have been developed, systematic procedures for assessing performance and quantifying reliability are still needed. This paper presents an analytical framework for assessing buckling-restrained braced frame (BRBF) reliability when subjected to seismic loads. This framework efficiently quantifies the risk of BRB failure due to low-cycle fatigue fracture of the BRB core. The procedure includes a series of components that: (1) quantify BRB demand in terms of BRB core deformation histories generated through stochastic dynamic analyses; (2) quantify the limit-state of a BRB in terms of its remaining cumulative plastic ductility capacity based on an experimental database; and (3) evaluate the probability of BRB failure, given the quantified demand and capacity, through structural reliability analyses. Parametric studies were conducted to investigate the effects of the seismic load, and characteristics of the BRB and BRBF on the probability of brace failure. In addition, fragility curves (i.e., conditional probabilities of brace failure given ground shaking intensity parameters) were created by the proposed framework. While the framework presented in this paper is applied to the assessment of BRBFs, the modular nature of the framework components allows for application to other structural components and systems.
KW - Buckling-restrained brace
KW - Cumulative plastic ductility capacity
KW - First-order reliability method
KW - Risk and reliability analysis
KW - Stochastic dynamic analysis
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U2 - 10.1007/s11803-009-9013-8
DO - 10.1007/s11803-009-9013-8
M3 - Article
AN - SCOPUS:70349641182
SN - 1671-3664
VL - 8
SP - 373
EP - 385
JO - Earthquake Engineering and Engineering Vibration
JF - Earthquake Engineering and Engineering Vibration
IS - 3
ER -