Estimating the response of concrete moment frames subjected to individual ground motions using endurance time excitation functions tted to average acceleration response spectra

Endurance Time (ET) method is an efficient time history-based analysis procedure that applies special acceleration functions for estimating the seismic performance of structures at different excitation levels in every single analysis. For some structures with complex models, such as dams, it is impractical to conduct multiple seismic analyses due to the high computational cost. In such cases, for obtaining accurate structural responses, it is recommended that researchers pay conscious attention to choose compatible Endurance Time Excitation Functions (ETEFs) regarding the basic properties of their structures, such as the soil type of the site, the selected design spectrum, and the type of the analysis. However, in this study, it is observed that using various ETEFs to analyze a concrete moment frame subjected to a single earthquake ground motion will cause us to obtain unreliable responses. In other words, different ETEF series have signicantly different accuracies (26% error) in predicting the responses of the mentioned structure which is subjected to individual earthquake ground motions. This problem is mainly caused by the turbulent nature of a single ground motion spectrum, which is in contrast to the smooth shape of the ETEF spectrum. One solution to avoid this problem could be to produce a specic ETEF.