Yarı-rijit kompozit soğuk şekillendirilmiş çelik-kauçuklu beton binaların sismik performans değerlendirmesi

Over the past few years, cold-formed steel (CFS) structural elements have been extensively used as a cost-effective and fast way of achieving sustainable buildings thanks to their low embodied carbon. Besides, the increased demand for CFS systems in multi-story construction has led to the development of competent CFS lateral force-resisting systems with moment-resisting connections. These rigid connections are implemented to compensate for the shortcomings of traditional CFS framing systems that use simply supported floor-to-wall connections and hence cannot adequately dissipate large moments present in multi-story structures. With this in mind, this study focuses on the seismic performance evaluation of rubberised concrete-filled cold-formed steel (CFS-RuC) tube frames equipped with a recently developed semi-rigid moment-resisting connection. A numerical study is carried out in ABAQUS to examine the effect of different dimensions for CFS-RuC sections and side plates on the behavior of the semi-rigid connection adopted herein. A validation study of the semi-rigid connection is conducted in SAP2000 to come up with a practical plastic hinge model to use at frame-level analysis. Design of case studies of 2, 5, and 8 story- CFS-RuC buildings is accomplished per the TBEC 2018 and AISI-S100-16 codes. Seismic performance evaluation of the case study buildings at the performance point is investigated through nonlinear static pushover analyses. Alternatively, the seismic behavior of CFS-RuC buildings is probabilistically assessed through fragility curves generated by a fragility tool, SPO2FRAG. Results indicate that these new composite systems possess higher stiffnesses and adequate energy absorption capability in comparison to their bare counterparts. They also displayed a ductile deformation which enabled the fulfillment of the code-prescribed performance level of life safety.