Calculation of the local buckling in compression by the section damage method “case of the standardized profiles”

Local buckling in metal sections is such a threat that Eurocode 3 imposes a passage through the classification of the section before any verification of the resistance of the structural elements. This characterization process is not necessary for flexural design (all sections are class 1). While in compression, their areas have different strength classes, several of which are class 4. This work focuses on studying merchant profiles subject to the risk of local buckling in compression. The neglected (ineffective) part of their sections is supposed to be damaged, which allowed us to associate this local instability with the damage parameter. There, it was necessary to appeal to the damage mechanic notions to formulate the evolution of the local instability of the thin wall of a metallic section. This simplifying approach is proposed to directly obtain the effective characteristics of the normalized areas via a damage parameter (Dc) without resorting to the classification of the sections and the effective calculation. The results obtained led us to propose two empirical and predictive models of the damage parameter associated with local buckling. The latter was validated by an analytical calculation and subjected to a statistical analysis of their accuracy.