Web-post buckling resistance calculation of perforated high-strength steel beams with elliptically-based web openings for EC3

There has been an increase in the use of high-strength steel, as it provides lightweight structural members by satisfying environmental and economic issues. This paper aims to implement high-strength steels in the web-post buckling resistance equation, which was based on the truss model according to EUROCODE 3, presented previously by the authors. For this task, a finite element model is developed and employing geometrically and materially nonlinear analysis with imperfections. A parametric study is carried out, considering the key geometric parameters that influence the web-post buckling resistance. Three high-strength steel grades are studied (S460, S690 and S960) and in total, 13,500 finite element models are processed. A new factor for adapting high strength steels to the equation proposed previously was presented. The statistical parameters calculated, via the ratio between the numerical and analytical models, considering the regression, mean, standard deviation and variance, were 0.9817, 0.985, 8.29% and 0.69%, respectively. In conclusion, a reliability analysis was presented based on Annex D EN 1990 (2002).