Study Of The Compression Behavior Of Built-Up Members Composed Of Concentric Hot Rolled Circular Hollow Sections
Lucas Figueiredo Grilo1; Ricardo Hallal Fakury1; Francisco Carlos Rodrigues2; Ana Lydia Reis de Castro e Silva2; Afonso Henrique Mascarenhas de Araújo3
1 Programa de Pós-Graduação em Engenharia de Estruturas, Universidade Federal de Minas Gerais; 2 Programa de Pós-Graduação em Engenharia de Estruturas; 3 Divisão de Tubos Estruturais, Vallourec do Brasil
doi:10.20906/CPS/COB-2015-0494
Resumo
This paper presents a study of the compression behavior of built-up members composed of concentric hot rolled circular hollow sections. The use of these composed bars is an innovative solution of practical interest for situations in which a single bar does not reach the required compressive strength. This work presents a review the elastic buckling behavior of isolated bars, the influence of geometric and physical imperfection and the plastic hinge formation when the bar instability occurs. The current compressive strength formulation according to Brazilian Standard is presented. Some technically and economically viable design and fabrication solutions to built-up members composed of concentric hot rolled circular hollow sections are presented. For validation of numerical results, models of singular hollow sections are made and compared to the ABNT NBR 16239 (2013) Standard results. A mesh sensibility test is made, and the sizes of the elements are defined. The results obtained with numerical models are satisfactory. The numerical analysis shows that, for the processed models, the connection type between the inner and outer tubes does not affect substantially the compressive strength of the composed bar.
Palavras-chave: Buckling Curve; Axial Compression; Circular Hollow Sections; Steel Structures; Built-up Members