Strain‐hardening dependent cross‐sectional slenderness limits for the elastic resistance of steel beams

It is important that cross‐sections are correctly classified, as this determines their utilisation. The focus of this paper lies on the analysis of the transition point between cross‐sectional classes 3 and 4 for I‐shaped and hollow cross‐sections. In particular, it studies how various degrees of strain hardening and ratios between ultimate and yield strength influence this transition point, which defines whether the elastic moment resistance of a section can be exploited. Numerical simulations with geometrically and materially nonlinear analysis with imperfections (GMNIA) were carried out. The results of the numerical simulations were analysed and consequently, limit slenderness values could be determined and correlations to the hardening behaviour could be found and integrated into corresponding formulas.