| Autor: |
Sause, Richard, Ricles, James, Chancellor, Brent, Tahmasebi, Ebrahim, Tugce Akbas |
| Rok vydání: |
2014 |
| DOI: |
10.4231/d3ft8dk40 |
| Popis: |
Steel special concentrically braced frames (SCBFs) are efficient and economical seismic lateral force resisting systems. However, limited ductility capacity and structural damage as a result of brace buckling at low drift ratios (0.3% ~ 0.5%) is a drawback of SCBFs. The steel self-centering (i.e., post-tensioned, rocking) concentrically-braced frame (SC-CBF) is a new seismic lateral force resisting system that reduces or eliminates the structural damage and residual drift of SCBFs under design basis earthquakes (DBEs) while maintaining a sufficient margin against collapse under very rare maximum considered earthquakes (MCEs). In order to establish equivalent safety against collapse in an earthquake for SC-CBFs comparable to the inherent safety against collapse intended by current seismic codes, global seismic performance factors need to be evaluated. Nonlinear static pushover analysis and incremental dynamic analyses (IDA) are used as tools to assess median collapse capacity and to determine the collapse margin ratio (CMR) according to the recommended methodology by FEMA P695. The CMR and the adjusted CMR (ACMR) are calculated and reported this paper for the SCBF and SC-CBF systems studied. Various definitions of collapse for both SCBF and SC-CBF systems are also explored and compared. The appropriateness of each definition is discussed for both the SCBF and SC-CBF systems and the sensitivity of the CMR to changes in the definition of collapse is investigated. Finally, effect of inherent damping models on collapse capacity and probability of collapse is discussed. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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