Experimental investigation of panel zone in rigid beam to box column connection

This research presents the results of an experimental effort conducted on three full-scale rigid connections between I-beam and box-column. Accordingly, it is focused on the elimination of continuity plates from such connections through controlling the thickness of column flange. The appropriate thickness is determined by analytical method and then verified through experimental investigations of three different full-scale connections under AISC protocol of cyclic loading. Pre-qualified connections, presented in AISC (WUF-W) are selected for the test. They have the beam flange width to column flange width ratios of 0.53, 0.6 and 0.8, and beam flange width to beam depth ratios of 0.48, 0.72 and 0.65. According to the obtained results, panel zone remains elastic in all tested samples; and plastic hinges are formed in the beam and near the column flange. Moreover, the samples reach to the 6% story drift before experiencing the permissible strength degradation. Therefore the tested connections have satisfied criteria of special moment resisting frame (SMRF) according to AISC. According to the FEMA requirements for SMRF, no crack should be observed in the connection up to the story drift of 4%. However, in a sample of this experimental research, crack is observed in story drift of 3%.