ه علمی نشری- پژوهشی« مه ندسی سازه و ساخت» ازه ایران مهندسی ساجمن ن سال سوم، شماره3 ، یز پای1395 143 Research Note: An investigation on the effect of gusset plate connection rigidity on the seismic behavior of special concentrically braced frames Ali Esnaashari 1 , Amin Mohebkhah* 2 1- MSc, Department of Civil Engineering, Malayer Branch, Islamic Azad University, Malayer, Iran 2-Assistant Professor of Structural Engineering, Department of Civil Engineering, Malayer University, Malayer, Iran ARTICLE INFO ABSTRACT Received: 26/03/2016 Accepted: 18/11/2016 Special concentrically braced frames (SCBFs) are commonly used to resist lateral loads in buildings. The bracing system sustains large deformations due to inelastic behavior in bracing members (buckling and yielding in tension). Generally, in the conventional modeling strategy, the effect of gusset plates in providing beam-column connections rigidity and hence, improving the post-buckling performance of these frames is not taken into account. This paper deals with the effect of gusset plate rigidity on the seismic behavior of SCBFs using Roeder’s proposed model in the literature. In this paper, four 3, 6, 9 and 12-story SCBFs were designed and modeled using two distinct methods: conventional method with hinged connections and Roeder’s method with semi-rigid connections. Then, the models behavior was investigated with both pushover analysis and nonlinear time- history analysis using OpenSees software. The results showed that lateral load capacity of the frames modeled with the Roeder’s proposed model are about 10% larger than the conventional method’s capacity. Also, it was found that the semi-rigid model leads to a less drift ratios and more overstrength factors. Keywords: Special concentrically braced frames (SCBFs) Seismic behavior Gusset plate Propose model Nonlinear analysis All rights reserved to Iranian Society of Structural Engineering. DOI: 10.22065/jsce.2016.40261 http://dx.doi.org/10.22065/jsce.2016.40261 *Corresponding author: Amin Mohebkhah. Email address: amoheb@malayeru.ac.ir