Evaluating Design Methods for Cellular Steel Beams Through Parametric Modelling

Resumo

Under some design conditions, cellular beams can be a better structural solution than I-section beams due to their enhanced strength-to-weight ratio, allowing for more lightweight and cost-effective constructions. However, their varying cross-sections lead to additional failure mechanisms, which require further research due to the lack of specific standardized design procedures covering this topic in Brazil. This paper evaluates five different design methods, as proposed by Annex N (1998), Veríssimo et al. (2013), Fares et al. (2016) and Grilo et al. (2018). Using a parametric approach, this paper investigates the geometric variations in cellular beams with the mentioned design methods, in comparison to shell finite element models already validated in a previous work of Benincá and Morsch (2020). The results reveal that while the design methods are generally conservative for longer spans, they might underperform in terms of safety for shorter spans. The Ward (1990) method was the most effective in identifying failure modes based on Formation of Vierendeel Mechanism (FMV) and Web-Post Buckling (WPB). In contrast, the adaptation of the Veríssimo et al. (2013) method, combined with the WPB check from the Grilo et al. (2018) method, was more sensitive in evaluating the WPB failure load. Finally, the findings confirm that cellular beams offer more significant benefits when used across longer spans.