Estudo teórico-experimental do comportamento de barras compostas comprimidas formadas por perfis tubulares circulares concêntricos laminados de aço

• Ano de defesa: 2018
• Autor(a) principal: Glaucimar Lima Dutra
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Análise experimental; Compressão axial; Estruturas de aço; Perfis Tubulares circulares concêntricos; Engenharia de estruturas; Aço Estruturas; Carga axial; Compressores
• Link de acesso: http://hdl.handle.net/1843/BUOS-B3EJH6

This paper presents a theoretical-experimental study on the behavior of built-up members axially compressed formed by concentric hot rolled circular hollow sections. The use of these bars is an innovative solution for situations in which there is project restriction regarding the maximum diameter that can be adopted, or in which a single rolled section does not reach the required compressive strength. This study begins with the presentation of the behavior of compressed bars, approaching the aspects of structural stability, the influence of initial geometrical imperfections and material, the procedures of normative dimensioning and the collapse mechanism. The numerical study developed for concentric hot rolled circular hollow sections, as well as its assemble process and its calculus procedure were presented. During the experimental analysis, there were performed rehearsals of axial compressing strength on compound bars labeled at both their extremities, constituted by two and three concentric hollow sections, with no connection between the sections throughout the length and with sliding and embedded connections, in order to obtain the responses in terms of resistant capacity and assemble facility. In this stage, it was to develop a method to measure the geometrical imperfections of the sections that are part of the assembly. The numerical analysis was performed through simulations via Finite Element Method using the program ABAQUS. In these simulations, for the calibration of numerical models, were considered initial geometrical imperfections and geometrical relations obtained in the experimental models. The formulation proposed for the dimensioning of the concentric circular hollow sections presented conservative valuables. After the calibration validation, a parametric analysis was performed, varying the dimensions of the cross section of the tubes that compose the composed bars and the directions of the initial geometrical imperfections of these tubes, aiming to investigate the influence of these parameters on the behavior of the composed bar and on the valuable of the resistant strength.