Effect of out-of-plane stiffness and strength on buckling strength of hss brace with single-shear bolted joints

A typical bracing connection for hollow-structural-section (HSS) braces comprises a flat plate welded to the brace, a gusset plate, and a single-shear bolted joint between the flat plate and gusset plate. Where such bracing connection is adopted, the rotational stiffness and strength of the bracing connection must be taken into account to evaluate the brace strength in compression. This paper proposes analysis models for this problem, derives buckling strength formulae, and verifies the formulae with monotonie loading tests. Validated finite element models are used to conduct an extensive parametric study to verify the formulae over a wide range of geometrical properties. The proposed formulae predicted the buckling modes for 110 of 118 cases and estimated the brace strength within a coefficient of variation of 3.7% and error margin of 10% for the range of properties examined.