Influence of shape memory alloy brace design parameters on seismic performance of self‐centering steel frame buildings

• Published in: Structural control and health monitoring Vol. 27; no. 1
• Main Authors: Shi, Fei, Ozbulut, Osman E., Zhou, Yun
• Format: Journal Article
• Language: English
• Published: Pavia John Wiley & Sons, Inc 01.01.2020
• Subjects: Acceleration; Aseismic buildings; brace failure; Case studies; Collapse; collapse performance; Deformation; Design; Design parameters; Drift; Earthquakes; Failure analysis; Frame structures; incremental dynamic analysis; Nonlinear analysis; Nonlinear response; Performance assessment; Reinforcement (structures); Seismic activity; Seismic analysis; Seismic hazard; Seismic response; shape memory alloy; Shape memory alloys; SMA bracing system; Steel; Steel frames; Steel structures; Stiffness
• ISSN: 1545-2255; 1545-2263
• DOI: 10.1002/stc.2462

Summary This paper investigates the seismic and collapse performance of shape memory alloy (SMA) braced steel frame structures considering the effects of various brace design parameters and ultimate state of SMAs. An SMA‐braced steel frame building is designed to have comparable strength and stiffness with a steel‐moment resisting frame selected as case study building. Then, the stiffness and ultimate deformation capacity of the SMA braces in the initially designed reference SMA‐braced frame are systematically varied. First, the static pushover analysis and incremental dynamic analysis are employed to illustrate the significance of SMA brace failure consideration in seismic performance assessment of steel frames with SMA elements. Then, the influence of SMA brace initial stiffness and ultimate deformation capacity on the seismic and collapse performance of SMA braced frames are studied through pushover analyses, nonlinear response history analyses, and incremental dynamic analysis. The results show that the SMA brace initial stiffness does not affect the interstory drift and floor absolute acceleration response at design and maximum considered earthquake level seismic hazard or collapse capacity of the frame. However, it has considerable influence on post‐event functionality of the frame. It is also found that the SMA brace ultimate deformation capacity should be at least 80% of maximum interstory drift demand at maximum considered earthquake level for satisfactory seismic performance, whereas larger values provide higher collapse capacity for the SMA‐braced frame.