A modified ECBL approach for cold-formed steel rack section members

The calibration of appropriate buckling curves for interactive local/distortional-global buckling of thin-walled cold-formed steel members is a task well covered by the Erosion of Critical Bifurcation Load (ECBL) approach. In this context, here a modified formulation of the ECBL approach, based on a new definition of the mode interaction point, is presented. The Generalized Beam Theory is used to find the mode interaction points and the related imperfections. Pallet rack uprights in compression are studied to show the potentialities of the modified ECBL approach and mark the differences with the classical one. The buckling curves coming from the modified ECBL approach are also compared with experimental results and with the buckling curves evaluated following the EN15512:2009.