ABSTRACT
The provisions used in the considered codes basically belong to three main methodologies, which are known as: reduced thickness approach; effective width approach; and reduced stress approach. Each code prescribes geometrical conditions to be fulfilled by the stiffening element in order to rely on the effectiveness of the restraint; if these are not satisfied, a reduced restraint must be considered. The overall buckling of a thin-gauge beam is a typical example of coupled buckling, in which the effect of local buckling of the compressed parts of the section is coupled to the global phenomenon, the so-called lateral torsional buckling. The Italian Code considers the restraining effect of a lip when its length is greater than a prescribed minimum value. The interaction between local and global buckling plays a very important role in every member in compression. Every thin-gauge member can be considered as a set of straight and rounded walls.
