Nonlinear seismic assessment of steel moment frames using timehistory, incremental dynamic, and endurance time analysis methods

A recent method in the seismic assessment of structures is Endurance Time Analysis (ETA). ETA is a timehistory-based dynamic pushover procedure, in which structures are subjected to gradually intensifying acceleration functions called Endurance Time Acceleration Functions (ETAFs), and their performances are evaluated based on the equivalent intensity level that they can endure while satisfying required performance goals. In this paper, the accuracy of the ETA in the seismic assessment of steel moment resisting frames is compared with the Time History Analysis (THA) and Incremental Dynamic Analysis (IDA) methods. For this purpose, a set of mid-rise and high-rise frames were selected as a case study. Three sets of second generation ETAFs were used as input in the ETA method, and seven scaled ground motions were used for THA and IDA. It was found that ETA can estimate THA results in an equivalent target time, and also the general trend of IDA curves, with acceptable accuracy, while ETA requires considerably less computational effort in comparison with THA, and, especially, the IDA method.