Assessment of behavior factor of eccentrically braced frame with vertical link in cyclic loading

Abstract

Use of various Eccentrically Braced Frames for designing or retrofitting buildings and bridges is increasing daily. Thus, much research has been done or is being done in this area. In this study, a new type of these frame with vertical link is investigated. At first, Eccentrically Braced Frame with double vertical link (V-EBF) is introduced and then the parameters affecting links’ length selection are proposed to obtain shear behavior and finally its design method will be explained. To investigate the seismic behavior of this system, nonlinear analyses (material and geometry) under a one-way cyclic load have been used. Then, after ensuring the proper behavior of these frames, the effect of number of floors is also studied. In order to understand the behavior of these structures using non-linear static and dynamic analysis of building’s behavior factor, eccentric and exocentric systems were calculated and compared with each other. To investigate the seismic behavior of this system, non-linear analyses under one-way cyclic load are used. Then, after ensuring the proper behavior of these frames, the effect of length and number of stiffeners were studied. The results showed that all frames under shear behavior have adequate ductility and stiffness in addition to stability. But some cases including shorter links and web stiffeners have shown better performance.

Keywords: Eccentrically Braced Frames, vertical joint, seismic behavior, behavior factor