Ratio of Hysteretic and Input Energy Spectra for Nonlinear Structures under Seismic Sequences

In the last few years, several mainshock–aftershock sequences have demonstrated their effects on structures; especially after occurrence of an earthquake with high magnitude, number aftershocks tends to increase. For this reason, studies been oriented estimate influence structural response, most them in terms peak or residual displacement; however, energy plays important role for long-duration earthquakes. paper, bilinear SDOF systems different post-yielding stiffness are subjected seismic sequences, considering levels intensity aim compute constant-ductility spectra input (EI), hysteretic (EH) and ratio between (EH/EI). The results suggest that although demands tend increase as aftershock increases, it is observed very similar selected levels; hence, analytical equations predict proposed. can be used toward earthquake-resistant energy-based design buildings.