A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Effect of beam yielding on chevron braced frames
Abstract Special concentrically braced frames (SCBFs) are commonly used as lateral-load-resisting systems in seismic regions. Chevron (or inverted V-braced) SCBFs are used to accommodate architectural openings, such as doors, windows, mechanical openings and elevators. However, current AISC provisions for SCBFs require beams of chevron SCBFs to be designed to resist large vertical and axial demands resulting from unbalanced brace forces due to post-buckling compressive strength deterioration and full tensile yielding of the braces. As a result, very large beams are required to support the braces, and chevron SCBFs are seldom built today. Recent research showed that limiting beam response to elastic behavior may reduce the overall deformation capacity of chevron SCBFs and some beam yielding may be beneficial. A research study was initiated to investigate the advantages of and limits for beam yielding. Six large-scale, single-story chevron SCBFs were designed, built, and tested to investigate current SCBF requirements and the impact of reducing the beam strength below current requirements to permit beam yielding. Nonlinear continuum analyses were performed using the Abaqus finite-element analysis program to extend the experimental research. The research shows that chevron SCBFs with moderate beam yielding may have improved seismic performance compared to other SCBF configurations. Yielding of the beam increases its deflection, but the increased beam deflection increases inelastic deformation capacity of the braces prior to brace fracture. The maximum lateral resistance and overstrength of the frame is reduced, but the resulting resistance remains larger than the design target and is retained through relatively large story drifts.
Highlights Testing of special concentrically braced frames with varied beam strength Continuum finite-element analysis used to investigate other beam strengths Beam yielding decreases brace tensile demands and enhances system ductility Adequate nonlinear response with about one-third of current required beam strength
Effect of beam yielding on chevron braced frames
Abstract Special concentrically braced frames (SCBFs) are commonly used as lateral-load-resisting systems in seismic regions. Chevron (or inverted V-braced) SCBFs are used to accommodate architectural openings, such as doors, windows, mechanical openings and elevators. However, current AISC provisions for SCBFs require beams of chevron SCBFs to be designed to resist large vertical and axial demands resulting from unbalanced brace forces due to post-buckling compressive strength deterioration and full tensile yielding of the braces. As a result, very large beams are required to support the braces, and chevron SCBFs are seldom built today. Recent research showed that limiting beam response to elastic behavior may reduce the overall deformation capacity of chevron SCBFs and some beam yielding may be beneficial. A research study was initiated to investigate the advantages of and limits for beam yielding. Six large-scale, single-story chevron SCBFs were designed, built, and tested to investigate current SCBF requirements and the impact of reducing the beam strength below current requirements to permit beam yielding. Nonlinear continuum analyses were performed using the Abaqus finite-element analysis program to extend the experimental research. The research shows that chevron SCBFs with moderate beam yielding may have improved seismic performance compared to other SCBF configurations. Yielding of the beam increases its deflection, but the increased beam deflection increases inelastic deformation capacity of the braces prior to brace fracture. The maximum lateral resistance and overstrength of the frame is reduced, but the resulting resistance remains larger than the design target and is retained through relatively large story drifts.
Highlights Testing of special concentrically braced frames with varied beam strength Continuum finite-element analysis used to investigate other beam strengths Beam yielding decreases brace tensile demands and enhances system ductility Adequate nonlinear response with about one-third of current required beam strength
Effect of beam yielding on chevron braced frames
Roeder, Charles W. (author) / Sen, Andrew D. (author) / Terpstra, Clare (author) / Ibarra, Sara M. (author) / Liu, Ruyue (author) / Lehman, Dawn E. (author) / Berman, Jeffrey W. (author)
Journal of Constructional Steel Research ; 159 ; 428-441
2019-04-26
14 pages
Article (Journal)
Electronic Resource
English
Response modification factors of chevron-braced frames
| Elsevier | 2004
Response modification factors of chevron-braced frames
Online Contents | 2005