An appraisal of the Vierendeel mechanism capacity of cellular beams with sinusoidal openings

• Published in: Journal of constructional steel research Vol. 198; p. 107539
• Main Authors: França, Gabriela M., Weidlich, Christovam M., Sotelino, Elisa D., Cardoso, Daniel C.T.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2022
• Subjects: Castellated beams; Plastic hinges; Sinusoidal openings; Vierendeel mechanism; Castellated beams; Plastic hinges; Vierendeel mechanism; Sinusoidal openings
• ISSN: 0143-974X; 1873-5983
• DOI: 10.1016/j.jcsr.2022.107539

The aim of this research is to investigate the performance of castellated beams with sinusoidal openings against Vierendeel mechanism (VM). Material nonlinear finite element (FE) analyses were conducted in two beams subjected to four-point bending with geometries selected to exhibit the desired plastification mode. Results of simulations revealed failure mode associated with the formation of four predominant plastic hinges along with shear yielding of the web-post necked region. Differently from the usual castellated beams with hexagonal or cellular openings, the critical hinges did not form at the ‘corners’ around a single opening, but at the innermost and outermost ‘corners’ at shear span. A significant stress redistribution could also be observed during the plastification process. The observation of a unique diagonal stress pattern along the web of the analyzed beams inspired the development of a simple two-dimensional model to predict the performance. A simplified nonlinear procedure was successfully developed to assess the evolution of plastification process with loading, with good agreement with the FE model and with an experimental result reported elsewhere in literature. Finally, it is shown that the current design guidelines for castellated beams (hexagonal and cellular) are not readily applicable to beams with sinusoidal openings for assessment of VM capacity. •Development of Vierendeel mechanism in beams with sinusoidal openings is investigated.•FE analyses reveal that hinges form at the extreme ‘corners’ at shear span.•The unique diagonal stress pattern inspired the development of a simple two-dimensional model.•Proposed nonlinear analyses are used to explain the migration of stresses and development of plastic hinges.•Current design guidelines for castellated beams are not readily applicable to beams with sinusoidal openings.