HSS Truss Connections with Three Branches

Hollow structural section (HSS) three-branch (or KT) connections frequently occur in modified Warren trusses, but the design of these planar welded connections is beyond the scope of Chapter K of the 2010 AISC Specification for Structural Steel Buildings. Such connections are also not covered by other contemporary HSS design guides and standards. This paper reviews the many potential member and loading arrangements, for both gapped and overlapped KT connections, and offers some design guidance. A worked example for an overlapped square HSS KT connection is then given, in both LRFD and ASD formats, in accordance with the 2010 AISC Specification for Structural Steel Buildings.