Application of damage spectra as seismic intensity measures in Endurance Time method for steel moment-resisting frames

Abstract

Abstract. In seismic resistant design of moment frames, the structure behavior under earthquakes has to be examined considering various damage criteria. Damage indices can be estimated by Endurance Time (ET) method with minimum computational e ort. The quality of this estimation can be improved in di erent ways. In this paper, the graphs of a certain damage index versus natural period of the structure, called damage spectra, are produced applying intensifying ET records and scaled Ground Motions (GM). Then, the excitation duration of ET acceleration functions (target time) is modi ed in order to reach acceptable consistency between ET and GM damage spectra. Moreover, various damage indices of a steel moment frame at two hazard levels are evaluated via nonlinear time-history analyses of the structure under scaled earthquakes and ET records. It is observed that the frame damage estimation can be improved by modifying the target time of ET records based on damage spectra. In addition, in most cases, there are negligible discrepancies between values of frame damage indices corresponding to ground motions and ET acceleration functions with the damage-based target time.

Effects of Six Earthquake Scaling Methods on Drift Demand Distribution of Buckling Restrained Braced Frames: A Comparative Study with Endurance Time Method

“…Mainly, the Endurance Time Method represents a promising approach to seismic investigation, providing valuable information for the design and retrofitting of structures to improve their seismic performance. Its unique ability to identify critical points in a structure's response can help engineers and researchers develop more effective seismic-resistant systems (Estekanchi et al,2007;Basim and Estekanchi, 2015;Maleki-Amin and Estekanchi, 2017).…”

Evaluating Performance of Concrete Special Moment Resisting Frames with Different Seismic Coefficients Using Endurance Time Method

“…Their results reported that input motions of the ET method, generated based on a design response spectrum can be used to assess frames at different seismic hazard levels correctly. Maleki-Amin and Estekanchi [14] evaluated various damage indices of a steel moment frame at two hazard levels via nonlinear time-history analyses of the structure under scaled earthquakes and ET records. They observed that in steel moment-resisting frames, the frame damage estimation can be improved by modifying the target time of ET records based on damage spectra.…”