Characteristics of Second Generation Endurance Time Acceleration Functions

The endurance time (et) method is a time-history based dynamic pushover procedure in which structures are subjected to specially designed, intensifying accelerograms, and their seismic performance is judged based on the time duration needed to satisfy the required design objective. second generation refers to et acceleration functions that are generated by application of optimization techniques in order to produce response spectra compliant linearly intensifying accelerograms. in this paper, the major characteristics of a set of second generation et acceleration functions (eta20a01-3) are investigated.the template response spectra of this set of et acceleration functions corresponds to the design spectra of the iranian national building code (standard 2800) for sti soil (type ii). results show that a good correspondence can be established between the effective ground motion parameters of earthquakes and et acceleration functions at specic target times. therefore, it is expected that et acceleration functions can be used to predict various demand parameters of structures subjected to ground motions whose respons espectra is more or less compatible with the adopted template response spectra. discrepancies between characteristics of et acceleration functions and ground motions have also been discussed.