Endurance time method in the linear seismic analysis of shell structures

Endurance Time (ET) method is a response history based analysis procedure that can be used for estimating the seismic response of structures at different excitation levels in each response history. This seismic analysis method utilizes specific intensifying acceleration functions to analyze seismic behaviors. One of the potential applications of the ET method is in the seismic assessment of shell structures. In this study, a procedure for linear seismic analysis of shell structures is proposed and applications of this method is investigated for several cases of shell structures. These structures are analyzed under three ET acceleration functions in one direction and the results are compared to time history analysis considering seven actual earthquake records. Moreover, the results of the ET method are compared to response spectrum analysis method. The outcomes of the study reveal that the ET method predicts the linear seismic performance of shell structures with acceptable precision and significant reduction in analysis time. Furthermore, it is conluded that scattering of results of three ET analysis is very low and one analysis can be used instead of three. Finally, the comparison between THA and RSM results verify that response spectuarm method is a conservative method which occasionally encounters problems to evaluate bending stresses of shell structures.