Behavior of longitudinal plate-to-rectangular hollow structural section K-connections subjected to cyclic loading

This study investigated the behavior of longitudinal plate-to-rectangular hollow section (RHS) K-connections to which concrete-filled composite branch members were jointed. At the connections, longitudinal plates with or without chord face stiffener were welded to the RHS chord member and the branch members were connected to the longitudinal plates by bolting (slip-critical connection). Cyclic tests were performed for three longitudinal plate-to-RHS K-connection specimens. The tests showed that the connection behavior was dominated by the plastification of the thin chord face and by the slip and hole-bearing resistance of the bolted joint. Chord face plastification was prevented or delayed by using the stiffened longitudinal plate. The strengths of the plate-to-RHS K-connections with or without the chord face stiffener, depending on the governing limit states, were estimated in accordance with current design codes, and the results were compared with the test results.