چكيده به لاتين
This study investigates the effect of seismic sequence on special and ordinary multistory X concentrically braced frame. Three frames with 4, 7 and 10 stories representing low, medium and high rise structures, with a proper range of periods are analyzed by nonlinear time history method under as-recorded records with and without seismic sequence phenomena.
Seismic scenarios of earthquakes recorded at similar stations and directions have been selected. Structures are initially designed with seismic design codes and then controled under seismic sequence effects.
Structural responses such as final structural displacement, ductility demand ratio, Park-Ang damage index, drift and residual displacement under seismic sequence phenomenon are calculated.
The results indicate that records with PGA ratio of consecutive records to single’s less than 0.5 do not have any significant effect on the response. As PGA ratio increased, the effect of seismic sequence on the frames is more considerable. The effect of the seismic sequence phenomenon on the ordinary concentrically braced frame will be greater than special concentrically braced frame. Also, the effect of this phenomenon on low frames is impressive compared to high-rise frames.
Keywords: Recorded seismic sequence, Concentrically Braced Frame, Nonlinear Time Histories Analysis, Park-Ang Damage index.