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 graduallyintensifying acceleration functions called endurance time acceleration functions (etafs), and theirperformances are evaluated based on the equivalent intensity level that they can endure while satisfyingrequired performance goals. in this paper, the accuracy of the eta in the seismic assessment of steelmoment resisting frames is compared with the time history analysis (tha) and incremental dynamicanalysis (ida) methods. for this purpose, a set of mid-rise and high-rise frames were selected as a casestudy. three sets of second generation etafs were used as input in the eta method, and seven scaledground motions were used for tha and ida. it was found that eta can estimate tha results in anequivalent target time, and also the general trend of ida curves, with acceptable accuracy, while etarequires considerably less computational effort in comparison with tha, and, especially, the ida method.