Abstract: “Using inappropriate system overstrength factors may lead to weak seismic performance or uneconomic results. Regulations suggest the suitable system overstrength factors for various seismic force-resisting systems. This is while a lot of parameters might affect on this factor. In this paper, the effects of various parameters such as the type of the moment frame, Seismic Design Category (SDC) and height of the building on overstrength factors of steel Moment Resisting Frames (MRF) are investigated. Hence, 12 buildings with perimeter steel MRF are designed three-dimensionally based on ASCE/SEI 7-10, AISC-LRFD 360-05 and AISC 341-05 regulations. Then, 24 two-dimensional MRFs of these buildings are simulated in OpenSees software and by conducting the Nonlinear Static Analysis (NSA); pushover curves of these structures are obtained. Finally, having these curves, relevant overstrength factors are gained. The results demonstrate that although altering the mentioned parameters, changes the over”

Keywords: Nonlinear Static Analysis, Overstrength Factor, Pushover Curves, Steel Moment Resisting Frames