Coupled buckling design of steel laced columns

Abstract

A new design method developed by the authors that gives an opportunity to account for the interaction of different modes of buckling is presented. Eurocode 3 model is used as the reference model. In the reference model, an equivalent geometric imperfection comprising of an initial bow being equal to the length divided by 500 is used. The model is based on the design criterion referred to the individual chord components. It allows to avoid the application of a complicated procedure based on an explicitly given imperfection parameter. It is achieved by a treatment of the chord local buckling mode between lacing connections in the same way as the plate buckling of chord sectional elements. The buckling design of the compound member can therefore be carried out in the same way as for a single element provided that the shear stiffness of lacing members is properly taken care of.

Keywords: Laced column, coupled buckling, design concept, implicit imperfection parameter model