Comportamento estrutural de seções cruciformes constituídas de cantoneiras de abas iguais de aço inoxidável

• Autor(a) principal: Botelho, Igor Sandez
• Data de Publicação: 2018
• 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/1/11495
• topic: Civil Engineering; Structural analysis (Engineering); Structures of steel; Hot-rolled angles; Starred angle; Stainless steel; Structural behavior; Compression resistance; Eurocode; Experimental analysis; Engenharia civil; Análise estrutural (Engenharia); Estruturas de aço; Cantoneira laminada de seção cruciforme; Aço inoxidável; Resistência à compressão; Análise experimental; CNPQ::ENGENHARIAS::ENGENHARIA CIVIL

Stainless steel has been used in several types of constructions because of its high versatility, having as main characteristics, the high resistance to corrosion (property that distinguishes it more from carbon steel) and high temperatures, besides good mechanical resistance, toughness and fatigue requiring few maintenance requirements. Although many of the mechanical properties are similar to the properties of carbon steel, nonlinear characteristics imply different sizing rules. This nonlinearity mainly affects the response to local and global buckling with some more stringent limits for the classification of the section. With the increasing use of stainless steel in structures, the first standard for sizing elements in stainless steel, Eurocode 3: Part 1-4, which includes hot rolled, welded and cold formed products was published in 2006. Some of the areas that demand research and studies are related to the behavior of stainless steel columns composed of angle brackets subjected to compression forces. This was the motivation for the present dissertation that aimed to study the behavior and the resistance of this type of column. Eight tests were carried out on 304 austenitic stainless steel angles of nominal section L63,5x63,5x4,76 with a longitudinal length of 700 mm, the first two being made in a single angle and the last six made up of two cross-shaped angles, known as starred angles. The tests were carried out with three constructive variations: angles without internal connection between them, angles connected by welding and angles connected by bolted plate. In order to obtain the values of the modulus of elasticity, yield stress, rupture stress and stress versus strain curves, tensile characterization tests were carried out in addition to compression characterization tests. Then, numerical analyzes were performed using the finite element method in ABAQUS 6.14 and later calibrated with the results obtained in the experimental tests. Finally, these results were compared with the calculation methods recommended in Eurocode 3: Part 1-4 and the Continuous Strength Method, a method that has not yet been included in the European standard up to the present moment. The mode of ruin presented by the single-angle columns was that of flexo-torsional buckling. However, for the models formed by two cross angles, there was a predominance of the torsional mode, however, with flexo-torsion angles (but with a slightly pronounced bending mode). As for the numerical models, the results were satisfactory, with load variations lower than 8% in relation to the experimental results, horizontal and vertical displacements, vertical deformations and deformed configurations similar to the tested columns. Regarding the theoretical results calculated by the recommendations of Eurocode 3, Part 1-4, these presented extremely conservative load values when compared to the experimental values. Already the theoretical results calculated through the formulations of the Continuous Strength Method were acceptable.