DESIGNING ECCENTRICALLY BRACED STEEL FRAMES WITH DIFFERENT LINK LENGTHS ALONG THE FRAME HEIGHT

摘要

12 eccentrically braced steel frames are designed according to LRFD (1999) and ASCE 7-05. Capacity-based design principles are based on AISC Seismic Provisions (2005). Some of the model frames have different link lengths along the height. Inelastic dynamic analyses of each of model frames are performed under 20 SAC ground motions with DRAIN-2DX. Each earthquake record for each frame is scaled by a coded program by modifying the DRAIN input files in an automated manner until one of the links reaches the code-based limit rotation angle, and the resultant scale factors are used for assessment of the frames' inelastic behaviours. Effects of the different link lengths along the frame height on the frames' seismic behaviours and weights are investigated. Push-over analyses of the designed frames are also performed with DRAIN-2DX in order to compare their displacement ductilities.