Seismic performance evaluation of steel moment resisting frames with WUF-B connections

Abstract

The purpose of this study is to evaluate the seismic performance of the moment resisting steel frames having Welded Unreinforced Flange-Bolted web (WUF-B) connections. The connections are designed and detailed in compliance with FEMA 350 recommended seismic design criteria. To conduct the seismic performance evaluation this study developed an analytical model for the pre-and post-Northridge connections based on test results. Three different frames are considered which have three-, nine-and twenty-story. Incremental Dynamic Analysis (IDA is conducted to estimate limit state capacities The performance of the frames having either pre-or post-Northridge connections is compared with the corresponding frame with ductile connections which do not experience connection fracture. The analytical results showed that buildings with post-Northridge WUF-B connections provide superior strength and interstory drift ratio capacity than buildings with pre-Northridge WUF-B connections.