A Target Displacement for Static Pushover Analysis to Estimate Seismic Demand of Eccentrically Braced Frames

A main challenge for performance-based seismic engineering is to develop simple, practical and precise methods for analyzing designed buildings and assessing existing structures to satisfy considerable performance objectives. Pushover analysis is a simplified nonlinear analysis technique that can be implemented for estimating the dynamic demands imposed on a structure under earthquake excitations. In this method, structure is subjected to specified load pattern to reach a target displacement. The present study provides a target displacement for estimating the seismic demand of eccentrically braced frame system (EBFs). A parametric study is conducted on a group of 30 EBFs under a set of 15 far-field and near-field accelerograms. The results of nonlinear dynamic analyses of EBFs have been post-processed by nonlinear regression analysis and a relation is proposed for target displacement. In order to verify the capability of the proposed procedure, three EBFs are assessed by the present method in which the results show that the proposed method is capable of reproducing the peak dynamic responses with relatively good accuracy. Additionally, the comparison of obtained results with those of other conventional target displacement methods such as N2 method, and displacement coefficient method confirms the efficiency of the suggested one.