Influence of the Type of Bracing System on Dynamic Response of Steel Frames

This paper presents an overview of comparing the dynamic response of steel braced frames subjected to seismic loadings. To perform this study, four types of bracing systems including X-bracing, Diagonal bracing, chevron-inverted V and chevron-inverted V type EBF, with 3, 6, 9 and 12- story frames are modeled and designed in accordance with AISC-ASD 89 code. To compare the dynamic characteristics of considered structural systems, nonlinear static analysis was conducted. The parameters which are evaluated and compared in these models are consisted of economical viewpoint with evaluating the weight of the structures based on steel used, the maximum roof displacement, behavior factor, ductility and the energy absorption. Results indicate that response modification factors (R) have different values depending on the brace configuration type and the building height. However, EBFs possess the highest amount of R factors, it seems in order to obtain the light weight structure, as well as the high energy absorption capacity, the best solution among compared bracing systems, is to apply the Inverted-chevron V bracing systems in steel frames. Obtained results are presented in relative diagrams and tables.

Keywords:

braced frames , push over analysis , ductility , energy absorption capacity