Introducing a new seismic efficiency index of post-tensioned self-centering steel moment connections

Assuming that damages to buildings in earthquake are repairable, retrofitting them is not always economically justified. As an alternative solution, buildings can be designed such that damages are limited to only easily repairable elements. One of the structural systems that provide this possibility is the post-tensioned self-centering moment resistant frame. In self-centering structures, after the event of an earthquake, due to an opening in the gap of beam to column connection and with the help of highly resistant strand tension, residual drift is eliminated. In this study, an attempt is made to develop an efficiency index of post-tensioned self-centering steel moment resistant connections through the analyses of dispersion indices. After a time-history and parametric analysis of three models of steel buildings with self-centering connections, a model will be selected for evaluating the efficiency index that has the lowest sensitivity resulting from dispersion analysis in the study population. Then, between the seven introduced indices, efficiency indices will be compared and optimized. Evaluations show that the Efficiency index of self-centering frame (EISCF), calculated based on coefficient of variance, will increase the accuracy and speed of analysis.