Abdolrahim Jalali - Assistant professor, civil engineering faculty, Tabriz University
Yousef Hosseinzadeh - Associate professor, civil engineering faculty, Tabriz University
Nasim Irani Sarand - M. S. in civil engineering, Tabriz University
Akbar Danesh - PhD student of civil engineering, University of Tehran

Chevron braced frames are typical lateral load resisting system which have poor performance due to buckling of the compressive braces and forming soft story mechanism. To improve the seismic behavior of chevron braced frames and overcome these disadvantages of chevron braced frames, zipper braced frames have been proposed. In order to investigate the seismic behavior of zipper braced frames 3, 6, 9 and 12 story zipper braced frames were designed and modeled in ABAQUS. Nonlinear time history analyses showed that seismic performance of chevron braced frames improved by adding zipper columns due to uniform damage distribution over the building height

chevron brace, nonlinear time history analyses, unbalanced force, zipper column