The analysis of some practical methods for limit state verification in coupled instability—comparison with the experimental evidence

The paper analyzes the concept of evaluation by calculus of the stability limit state for members subjected to combined bending and axial compression.

The calculus procedure stipulated in Eurocode 3, Design of Steel Structures, 1990¹ is presented for the case in which flexural-torsional buckling is a potential failure mode (compression and bending about the major axis of the section).

The verification function, stipulated in the Eurocode is analyzed by comparison with some experimental results.

The analysis is one of the Steel Structures Department's (Civil Engineering Institute, Bucharest) concerns regarding the improvement of Romanian Code STAS 10108/0–78 ‘Metal Structures’.