Some remarks concerning the buckling reduction factors

A possible design model is proposed for the stability check of steel structural members (columns, beams and beam - columns). It is suggested to base the verification on the design yield strength f(y)/gamma(M1) instead of the nominal yield strength f(y) (as specified by EC3). This model is a simplified but intuitive one, which is physically conceivable. It is expected that by an adequate calibration of the imperfection parameter alpha (more exactly of its geometrical component alpha(g)2), a satisfactory agreement can be obtained between the proposed model and the experimental data. Another aspect which deserves consideration is that the overall buckling load can be reduced owing to local buckling, not only in the case of Class 4 cross sections, but also for Class 3. A simplified procedure is suggested for taking into account the lower bearing capacity of members having Class 3 cross sections, caused by their lower ductility as compared to the cases when the cross sections belong to Classes 1 or 2.