Cyclic Testing of Welded HSS-to-HSS Moment Connections for Seismic Applications

Abstract

AbstractHollow structural sections (HSS) are currently underutilized in seismic moment frame systems as possible alternatives to typical wide-flange members. To explore the potential use of HSS moment connections in seismic moment frame systems and evaluate connection detailing requirements, experimental tests of welded unreinforced and reinforced HSS-to-HSS connections are conducted under increasing cyclic rotations to failure. The behavior of the unreinforced connections is limited by their inability to isolate inelasticity to the beam member and panel zone region leading to eventual fracture at lower than anticipated drift levels. However, through plate and external diaphragm plate reinforced HSS-to-HSS moment connections are able to move the location of inelasticity into the HSS beam member resulting in desired beam plastic hinging. Although the unreinforced connections have limited ductility, the reinforced connection detailing leads to stable degradation of the moment capacity at increasing drift le...