Development of repairability index for steel moment frames with post-tensioned self-centering connections

Abstract

With regard to the effects of self-centering structural performance in reducing damages in the event of an earthquake, in this study an attempt is made at developing a repairability index for post-tensioned self-centering steel moment connections. Based on the 18 structural models studied, a building in which the maximum connection rotation does not exceed the allowable rotation of the immediate occupancy level is considered repairable. Accordingly, the output data of Incremental Dynamic Analyses have been depicted in OpenSees under 22 sets of near and far-field strong ground motion accelerograms based on connection relative rotation and spectral acceleration the Repairability Index of Self-Centering Frame (RISCF) will be obtained. For input of spectral acceleration of the first mode of the structure in the repairability equation, if this amount is smaller than 1, the aim of repairability is met. In order to qualitatively evaluate angle damages, the Angle Failure Probability of Self-centering Frame (AFPSCF) will be depicted with regard to the fragility curve, if the number is less than 1, the building can return to its previous performance level with angle replacement after the event of an earthquake.