Tests of bolted and internal sleeve knee connections in cold-formed RHS

This paper examines different knee connections for portal frames constructed from cold-formed rectangular hollow sections: bolted plate connections, and welded and bolted internal sleeve connections. The specimen joints were tested in both tension and compression (opening and closing moments) to simulate wind uplift or gravity loading. It wits found that the sleeve connections were capable of sustaining the plastic moment for large rotations considered suitable for plastic design. The use of an internal sleeve moved the plastic hinge in the connection away from the connection centreline and reduced the stress on the weld between the RHS. However, at present, the sleeve connection may not be a commercially viable possibility. The bolted plate connection achieved plastic rotations but failed in the heat affected zone in tension.