Unified buckling length coefficient for sway and non-sway structures

Traditionally, a distinction has been made between sway and non-sway behavior in determining the buckling length of the columns of any structure. Both behaviors are treated using a common assumption: for the beams and columns that connect at one node, the remote ends have the same rotation. This assumption is employed for the calculation of the buckling length using a new formulation that explicitly considers the stiffness providing lateral restraint. Two interesting results come out of this new formulation: (1) The traditional classification between sway and non-sway structures can be abandoned, now that a single formulation for the buckling coefficient is available that considers the stiffness of the bracing system, and (2) a tool for the design of the bracing systems, that allows the effect of the stiffness of the bracing system on the buckling coefficients of the columns of a structure. Several examples are presented.

► A new theoretical approach for the calculation of the buckling length of framed structures is presented.
► The new formulation unifies the buckling length formulation for sway and non-sway structures.
► In what follows the sway and non-sway classification is no longer needed.
► The new formulation provides a tool for the design of the bracing systems.