Avaliação numérica de estabilidade lateral de vigas casteladas

• Autor(a) principal: Gama, Felipe Ozório Monteiro da
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/11532
• topic: Lateral stability; Lateral torsional buckling; Critical moment; Web opens; Castellated beams; Estabilidade lateral; Flambagem lateral com torção; Momento crítico; Aberturas na alma; Vigas casteladas; CNPQ::ENGENHARIAS::ENGENHARIA CIVIL

Restrictions of space and height are often imposed to residential, commercial, industrial, warehouses and sheds with one, or several floors, due to aspects like regional regulations, technical, economic or aesthetic nature. In order to provide the passage of pipes and ducts with large diameter under steel girders, that normally requires great heights, sometimes leads to floors building highs with an unviable magnitudes. Several structural solutions can be used to overcome these obstacles, where the most popular are the beams with variable inertia (tapered and haunched beams), stub-girders, trusses, and beams with one or more web openings with various geometries. When castellated beams, structural solution studied and discussed in this dissertation, are considered stability issues at the construction stage becomes to attract the structural engineer attention since the lateral bracing are not yet installed. The unbraced span lengths generally reached by these beams are often long enough to cause instability effects. However, the substantial enhancement in the flexural strength of such members, due to the extra height coming from the manufacturing process in relation with the original profile, combined with the economy of material and utility services, ensures to the designers the attractiveness of this solution, especially when applied to large spans. On the other hand, this proportional increase in span lengths enhances the significance of improving the beam lateral instability resistance. The present investigation aims to develop a numerical model, that calibrated with experimental results, enables the development of a parametric analysis. This analysis aimed to determine the structural behavior of the castellated beams and their associated failure mechanisms, considering an elastic-plastic behavior as well the geometric non-linearities. The investigation was also able to evaluate, quantify and determine the influence of geometry variables like span lengths and cross sections dimensions. The methodology used for this study was developed based on a parametric analysis centred on the finite element method.