Mohammad Kheirollahi - Department of Civil Engineering, Sahand University of Technology, Tabriz, Iran, Ph.D. Student of Structural
Ehsan Dadkhah Khiabani - 2Department of Civil Engineering, University of Tabriz, Ph.D. Student of Earthquake Engineering, Tabriz, Iran

The reduction of structural response under dynamic loads has cut serious attentions in recent decades. Steel yielding dampers are used as a devise to control the structural response under wind and quake loads. In this paper, three steel moment frame in 3, 5 and 8stories are analyzing in a nonlinear time history under four different motions. With respect to failure of elements, U-shaped steel yielding dampers have been added by knee braces of the structures. In this paper, in addition to defining nonlinearity of damper, nonlinear specification of beams and columns by assigning plastic hinges on this elements have been considered. The results show transferring nonlinearity of elements to the damper and the failure of the frame will reduce. Dampers will develop frame behavior and reduced lateral displacement and story shear. Also they increase energy dissipation of frame

energy dissipation ، plastic hinges ، nonlinear time history ،