en Structure-Steel Structure-Steel Technical Note Technical Note <p>Inelastic deformation of structural components is generally acceptable in seismic design. In such behavior, the strength of structures increases while plastic hinges are formed in members frequently. The strength revealed during the formation of plastic hinges is called "overstrength". Overstrength is one of the important parameters in the seismic design of structures. The present study tries to evaluate the overstrength of the concentrically steel braced frames (CBFs), considering reserved strength, because of members post-buckling. As such, a static nonlinear (pushover) analysis has been performed on the model buildings with single and double bracing bays, different stories and brace configurations (chevron V, invert Vand X-bracing). It has been realized that the number of bracing bays and the height of buildings have a low effect on reserve strength due to brace post-buckling. However, these parameters have a profound effect on the overstrength factor. These results indicate that the overstrength values for CBFs, proposed in seismic design codes, need to be modified.</p> Concentrically steel braced frames, Overstrength factor, Post-buckling strength, Response modification factor 57 62 http://ijce.iust.ac.ir/browse.php?a_code=A-10-233-1&slc_lang=en&sid=1 M. Mahmoudi m.mahmoudi@srttu.edu 1800319475328460010096 1800319475328460010096 Yes Shahid Rajaee Teacher Training University M. Zaree mahdizarebalani@gmail.com 1800319475328460010097 1800319475328460010097 No Shahid Rajaee Teacher Training University