Abstract Cellular beams are an attractive engineering solution due to their high strength to weight ratio, allowing for a design even lighter and more cost efficient in steel structures. These beams possess enhanced strength and stiffness compared to regular I-section beams of similar weight, due to their higher second moment of area. However, their variable cross-sections along the length introduce different modes of failure, making further research necessary, since there is a lack of standardized processes for their design. This paper investigates the design and verification procedures proposed by Ward (1990), Annex N (1998), Veríssimo et al. (2013), Fares et al. (2016), and Grilo et al. (2018) through a parametric study of cellular beams with varying geometries. To assess the buckling characteristics of cellular beams, shell finite element models are employed, which were previously validated, using experimental tests conducted by other researchers. The results obtained from a Python code implementing these design methods are then compared with Finite Element Method (FEM) analysis results for 80 beams. It can be concluded that the design methods provide conservative results for beams with intermediate or long spans. On the other hand, for beams with short spans, these methods may yield values that compromise safety. Finally, based on the FEM analysis results, a Hybrid Design Method (HDM) is proposed, which incorporates the verification procedures analyzed. This proposed method presents a better failure mode detection and limited load capacity when applied to cellular beams made from regular Brazilian I-section beams. ratio structures Isection I section area However crosssections cross sections necessary 1990, 1990 , (1990) 1998, 1998 (1998) al 2013, 2013 (2013) 2016, 2016 (2016) 2018 (2018 geometries employed validated researchers (FEM 8 spans hand safety Finally HDM (HDM analyzed 199 (1990 (1998 201 (2013 (2016 (201 19 (199 20 (20 1 (19 2 (2 (1 (

resumo: O emprego de vigas mistas de aço e concreto permite que sejam exploradas as melhores características mecânicas desses materiais, resultando em soluções estruturais mais econômicas. Vários pesquisadores estudaram o comportamento de vigas mistas a partir de diferentes estratégias de modelagem numérica, algumas das quais são apresentadas neste artigo. Dentro desse contexto, propõe-se a construção de um modelo numérico tridimensional com o software ANSYS, versão 19.2, utilizando elementos finitos atuais e modelos de materiais compatíveis com eles. Para a simulação do comportamento do concreto, foram utilizados dois modelos, o primeiro denominado DP-CONCRETE, disponibilizado nas versões mais recentes do ANSYS; e o segundo customizado com a interface USERMAT, e que tem por base o critério de Ottosen. Os resultados obtidos para as vigas analisadas apresentaram boa correlação com os resultados experimentais e com resultados numéricos de trabalhos anteriores.

abstract: The use of steel-concrete composite beams allows the best properties of these materials to be explored, resulting in more economical solutions. Many researchers have studied the behavior of composite beams from different strategies of numerical modeling, and some of these are presented in this article. In this context, the present work proposes the construction of a tridimensional numerical model using ANSYS software, version 19.2, with current-technology elements and compatible material models. For the simulation of concrete behavior, two models have been used: the first, denominated DP-CONCRETE, is a native ANSYS model, available in the more recent versions of this software; and the second, denominated USERMAT, is a customizable model that was developed based on Ottosen criterion. The results obtained with these models for the analyzed beams presented a good correlation with the experimental results and with numerical results from previous works.

Abstract Composite alveolar beams consist in the union of two structural systems largely employed in civil construction sector: the steel-concrete composite beams and the alveolar steel beams. Thus, its use allows their advantages to be enhanced, enabling to design even larger spans and to achieve more economical and sustainable solutions. Considering that Brazilian and international standards do not directly specify criteria for the analysis and design of these beams, in this paper it is presented the development and validation of an updated finite element model, using ANSYS software, capable of simulating different failure modes that may occur, such as web-post buckling, Vierendeel mechanism and flexural mechanism. The obtained results presented a good correlation with experimental results from previous works. After the model validation, the effect of the openings on the composite beam was investigated and discussed, and it was concluded that the web-post buckling may limit the structural gains on load capacity, so it is important to adopt opening patterns that enhance the resistance of the beam to this mode of failure.