Seismic Performance Evaluation of Eccentrically Braced Steel Frames with Intermediate Link Lengths

One of the natural disasters that cause many human and financial detriments in various countries is the earthquake phenomenon. In this regards, countries that are more at risk are extra concerned with problem solving procedures and have made progress in this regard. Certainly, one of these countries is Iran, which caused the occurrence of destructive earthquakes such as the earthquake of Buin Zahra, Manjil, Rudbar and Tabas, that led to further studies about establishing criteria for the design of seismic structures. In this way, the first distinctive guideline (2800 standard) planned for designing buildings against earthquakes in 1367. In addition, recently, the evaluation of nonlinear behavior and performance-based method have been introduced in the seismic evaluation of structures, in which research centers and agencies have been active in this field and presented their effort in related guidelines such as ATC and FEMA. In this study, the guidelines rules for assessing the seismic of steel structures with eccentric braced frame (EBF) were evaluated by 4, 8, 12 and 16 models with dual system. These guidelines are designed in accordance with the rules of Iran and the world and by applying several lateral loading patterns. Also, nonlinear static analysis on these models has been used to review and compare the responses with nonlinear dynamics analysis. In this study, some criterions of the mentioned guidelines are studied, which are about seismic evaluation of the eccentric braced frame (EBF) systems, then the results of the research indicate that the response of all structures other than short-term structures is influenced by higher modes.