Seismic Performance of Eccentrically Braced Frames with Shear Link

Abstract

The push-over nonlinear evaluation of four eccentrically braced frame performance was conducted to assess the plastic deformation and location of plastic hinges in buildings with six, nine, twelve and fifteen stories. The excessive plastification of out-of-beam members is revealed in the majority of these buildings while the AISC design provision allows the moderate plastification in these members. Therefore, the beams out of link might be in danger of fracture of web and flange. Likewise, this was controversial evidence in Chrischurch earthquakes. In order to modify this problem either using fixed connection of braced members or using the very short shear links which have less end moment force than out-of-link beams moment strength are recommended. By this modification, the response modification coefficients are calculated for these buildings which are almost equal to the provision value. The maximum plastic rotation of shear links recommended by provisions (0.08 radian) is the upper ultimate limit to prevent emerging of out-of-link member`s instability.