TY - GEN
T1 - Comparison of the seismic performance of multistory and multi-tiered braced frames
AU - Agarwal, A.
AU - Fahnestock, L. A.
N1 - Publisher Copyright:
© NCEE 2018.All rights reserved.
PY - 2018
Y1 - 2018
N2 - Steel braced frames are commonly used as lateral force resisting systems in seismic applications. In the case of tall single-story steel buildings, it is more economical to use multi-tiered braced frames (MT-BFs) in which the braced bay is divided into multiple panels over the height. In contrast to multi-story braced frames (MS-BFs), MT-BFs lack intermediate out-of-plane supports or diaphragms between the base and the roof. While the primary energy dissipation mechanism in both systems is brace inelastic axial response, the unique conditions in MT-BFs have been shown to cause inelastic drift concentration in one tier that can lead to column instability from combined axial and flexural demands. This study uses nonlinear static analysis to quantify the differences in seismic demand and behavior of the two configurations. The results for the 2-tier/story frames clearly demonstrate the need to consider flexural demands in MT-BF column design. Further, while column buckling occurs at lower roof drifts for the MT-BFs, the difference is more pronounced for the 2-tier/story frames than the 3-tier/story frames that have essentially the same response. In general, the results show that the overall demand in columns is higher in MT-BFs, but column instability can still occur in MS-BFs.
AB - Steel braced frames are commonly used as lateral force resisting systems in seismic applications. In the case of tall single-story steel buildings, it is more economical to use multi-tiered braced frames (MT-BFs) in which the braced bay is divided into multiple panels over the height. In contrast to multi-story braced frames (MS-BFs), MT-BFs lack intermediate out-of-plane supports or diaphragms between the base and the roof. While the primary energy dissipation mechanism in both systems is brace inelastic axial response, the unique conditions in MT-BFs have been shown to cause inelastic drift concentration in one tier that can lead to column instability from combined axial and flexural demands. This study uses nonlinear static analysis to quantify the differences in seismic demand and behavior of the two configurations. The results for the 2-tier/story frames clearly demonstrate the need to consider flexural demands in MT-BF column design. Further, while column buckling occurs at lower roof drifts for the MT-BFs, the difference is more pronounced for the 2-tier/story frames than the 3-tier/story frames that have essentially the same response. In general, the results show that the overall demand in columns is higher in MT-BFs, but column instability can still occur in MS-BFs.
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M3 - Conference contribution
AN - SCOPUS:85085590707
T3 - 11th National Conference on Earthquake Engineering 2018, NCEE 2018: Integrating Science, Engineering, and Policy
SP - 1482
EP - 1486
BT - 11th National Conference on Earthquake Engineering 2018, NCEE 2018
PB - Earthquake Engineering Research Institute
T2 - 11th National Conference on Earthquake Engineering 2018: Integrating Science, Engineering, and Policy, NCEE 2018
Y2 - 25 June 2018 through 29 June 2018
ER -