seismic performance of sturctures with CFST columns and steel beams

the paper presents performance of structures with concrete filled steel tubular CFST columns and steel beams under lateral loads and compares results with equivalent structures with ordinary reinforced concrete columns. To investigate seismic performance of frames with CFST columns 3,5 and 10 multi story moment resisting frames MRF were conducted and firstly static pushover analysis was performed on them then frames were analyzed with nonlinear dynamic method and by using several time histories of earthquakes in CFST column modeling confinement effect of steel tube and affects of steel progressive local buckling are considered. results show that frames with CFST columns have more strength ductility and energy absorption than frames with ordinary RC columns also these frames have better seismic performance.