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

Document Type : Article


Department of Civil Engineering, Sharif University of Technology, Tehran, Iran


Endurance Time (ET) method is a time history-based analysis procedure that applies special intensifying acceleration functions for estimating the seismic performance of structures at different excitation levels in every single analysis, and therefore, remarkably reduces the computational time, effort, and cost. For some structures with complicated models, such as dams, performing multiple seismic analyses are impractical. In such cases, it is recommended that researchers pay conscious attention to choose appropriate and compatible Endurance Time excitation functions (ETEF) considering the basic properties of their structure. However, in this study, it is observed that selecting and using various ETEFs for analyzing an intermediate concrete moment frame structure subjected to individual earthquake ground motions will lead us to obtain false and unreliable responses. In other words, different ETEF series have significantly different accuracies (over 26 percent error) in predicting the responses of the mentioned structure subjected to individual earthquake ground motions. This problem mainly arises due to the turbulent nature of the spectrum of a single ground motion which is in contrast to the smoothed shape of spectra of the ETEFs. One solution to avoid this problem might be to produce a specific ETEF.


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