ABSTRACT
For the member buckling check EN 1993-1-1 Method 2 distinguishes between members which are not susceptible to torsional deformations and members which are susceptible to torsional deformations. During the development of the new buckling formula, a study was necessary to clarify to which group pertain members with rectangular hollow sections (RHS). This paper deals of members with a buckling behaviour, which is at the limit between a failure with or without torsional deformations. This is the case for members with RHS with a high height-to-width ratio (h/b). Thereby, the influence of this ratio on the buckling behaviour of members with RHS is studied. The aim of the study is, to provide limiting values for the dimensions of the cross-section shape, for which lateral-torsional buckling is not relevant. Existing limiting values in codes or proposals are compared. For the investigation, numerical simulations are carried out on the basis of a geometrically and materially nonlinear analysis of the imperfect structure (GMNIA). Finally new limiting values are recommended and a proposal is made, how to proceed with hollow sections, if these values are exceeded.
