Development of 3-D segment model for the post-peak hysteretic analysis of CFT structures and its application to seismic design

Abstract

It is essential in the seismic design of concrete-filled tubular (CFT) structures to develop some analysis method that can be used to evaluate their superior post-peak energy dissipation capacity appropriately. Herein, a practical 3D segment model is proposed to reflect the complicated post-peak interface action between the locally buckled steel tube and the confined in-filled concrete. The segment model includes 18 parameters identified by an optimization technique, referring to the in-plane hysteretic behavior of the CFT members. The segment model analysis for the CFT structures dramatically reduces the long computation time required by the conventional FE analysis. A new direct seismic safety check method with the segment model is proposed.