BEHAVIOR OF REDUCED LINK SECTIONS IN ECCENTRICALLY BRACED FRAMES (EBFS)

摘要

Eccentrically braced frames (EBFs) are one of the most desirable seismic load resisting systems. In these systems, link beams have been accepted as a fuse that can limit plastic behavior in themselves. Although the architectural condition sometimes causes that structural engineers are obliged to use long links, former studies have shown unreliable behavior of these types of link beams. In this paper, the behavior of link beams is studied by finite element simulation. At first, the fundamental necessity for ultimate capacity estimation of the link beams has been explained. The results of simulation of link beams have been compared with an experimental study and good agreement is achieved. In order to improve the behavior of long links, the effect of use of reduced beam section (RBS) on link beams has been studied. It concluded that use of reduced beam section can control the plastic zone and cause reduction of the plastic region without any decline in ultimate capacity of long links, but it makes a slight decrease of plastic rotation capacity of short links.