Numerical simulation of shear-induced web-post buckling in castellated and cellular beams

Alveolar beams are steel structural members with regular web openings, the most common configurations being hexagonal (castellated) and circular (cellular). Due to the presence of sequential openings, these members, when subjected to shear force, may experience shear web post buckling (WPB), the phenomenon investigated in this study. Although several experimental investigations have been conducted over the last six decades, there is still no compilation in the literature of the geometric and mechanical properties and ultimate capacities of beams that failed due to WPB. Furthermore, numerical studies have employed different modeling strategies, either treating the full beam or adopting a single web-post (SWP) model, the latter remains without consensus on modeling methodology and lacks unified analyses of castellated and cellular beams. To address these gaps, a review comprising 69 experimental results was carried out, from which 32 cases (23 castellated and 9 cellular) were selected for the unified calibration of a numerical model representing a SWP. A total of 50 modeling strategies were evaluated, resulting in 1600 numerical models, considering variations in boundary conditions, mesh characteristics, and initial geometric imperfections. Among the evaluated strategies, five presented statistically more consistent performance, with coefficients of variation lower than 10%, and therefore recommended investigations related to the phenomenon. The study contributes by consolidating a unified methodology for the numerical assessment of WPB in castellated and cellular beams and recommends, for future studies, its application to alternative web opening geometries.