Análise numérica de ligações "K" compostas por perfis tubulares comdiagonais circulares com alta relação entre diâmetro e espessura

• Ano de defesa: 2016
• Autor(a) principal: Luana Perpétuo Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: afastamento; Ligações do tipo "K" com; Estruturas tubulares treliçadas; Estruturas de aço; Engenharia de estruturas; Aço tubular Estruturas
• Link de acesso: http://hdl.handle.net/1843/BUBD-AAZPZM

The trusses with tubular steel profiles often have overlap K type joints. The Brazilian Standard ABNT NBR 16239:2013, which specifically addresses steelwork design with hollow sections, presents a formulation for the design of these joints, but requires that the ratio between the diameter and the thickness of the compressed and tensioned braces do not exceed 0,05 E/fy (E is the modulus of elasticity and fy the yield strength of the steel) and 50, respectively. In this work, from numerical analysis by FEM using the ABAQUS program, the requirements of ABNT NBR 16239:2013 were evaluated for the possibility of applying in situations where the ratio between the diameter and the thickness of the braces is located between 0,05 E/fy and 0,11 E/fy. The second limit is equal to the maximum value of another Brazilian Standard, ABNT NBR 8800:2008, which deals with general design of steel structures, in order to have assurance that no local buckling occur of compressed bars. The numerical modeling involved a study of mesh refinement, in order to generate models with adequate number of elements and low processing time. In the analysis was considered geometrical and material non-linearity and large displacements and the numerical model will be calibrated based on results of scientific literature. In the end, it was concluded that the formulation of the ABNT NBR 16239:2013 cannot be applied safely in this expanded limit, because it does not take into account adequately the thickness of the diagonals in plastic failure of the chord face, greatness that affects the results significantly