Análise estrutural de colunas cruciformes formadas por cantoneiras de abas iguais em aço inoxidável submetidas à compressão axial

• Autor(a) principal: Torres, Flávio Lacerda
• Data de Publicação: 2022
• Outros Autores: [e-mail]
• 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/1/19338
• topic: Civil engineering; Steel - Structures; Metallic columns; Structural analysis (Engineering); Stainless steel; Engenharia civil; Aço – Estruturas; Colunas metálicas; Análise estrutural (Engenharia); Aço inoxidável; ENGENHARIAS::ENGENHARIA CIVIL::ESTRUTURAS

The wide range of possibilities for applications with the most varied purposes makes stainless steel suitable for use both structurally and architecturally. However, the non-linear characteristics of stainless steel demand different rules regarding its dimensioning, especially in the phenomena related to the instability of columns under axial compression. Stainless steel angle brackets are used as a structural component due to the ease in making connections between elements and the versatility in combining them, forming other sections with greater load capacity in response to requests. Based both on the demands mentioned above and on the scarcity of research related to the behavior of double angles with cross-section, the motivation to carry out the present work emerged. Cruciform columns were evaluated, formed by double angles with equal flaps hot-rolled in 304 austenitic stainless steel, with lengths of 900mm, 1400mm and 2200mm and cross sections of 50,8x4,76mm, 50,8x6,35mm and 50,8x7,93mm. Column dimensions were chosen based on elastic stability analysis using GBTul software. The design of numerical models and analyzes were performed with the aid of ANSYS 2019 R3 software. From the results provided by the analysis of elastic buckling of the columns, signature curves were created for columns with cross sections, formed by both simple and double cruciform angles (with and without interconnections). Signature curves provided important information about elastic buckling critical loads, column buckling modes, and column length where the transition between buckling modes occurs. Based on the buckling modes obtained, the initial geometric imperfections in the columns were introduced and their non-linear analyzes were carried out. With the results obtained in the numerical analyses, it was possible to observe the behavior of the columns against the introduction of interconnections between the double angles. It was observed that, in addition to the increase in the column's resistant capacity, the buckling mode to which the column is susceptible influenced the determination of the distance between interconnections, necessary to promote the column's joint work. When comparing the results obtained with the normative prescriptions of Eurocode 3, Part 1-1 [25] and of the AISC [24], it was possible to observe that some predicted normative values are too conservative. In addition, both standards do not point to the influence of the column buckling mode regarding the maximum distance between the interconnections to promote the column's joint work. Finally, a methodology was proposed to determine the optimal distance between the interconnections of double cruciform columns with a cross section formed by angle bars with equal edges, based on the buckling modes of the columns, capable of promoting joint work in the column.