Abstract This research presents a study of the behavior of built-up compressed steel members composed of concentric hot rolled circular hollow sections. The use of these members is an innovative solution of practical interest for situations in which a single member does not reach the required compressive strength. Some technically and economically viable design and fabrication solutions to built-up members composed of concentric hot rolled circular hollow sections are presented. For the validation of numerical results, models of singular hollow sections are made and compared to the EN 1993-1-1, and the results obtained with numerical models were satisfactory. The compression resistance of these numerical models differs less than 9% from the EN 1993-1-1 values. Once the numerical modeling was validated, the study of built-up members was made, considering the tubes always united at the extremities by end plates, and along the length by fixed interconnections or sliding interconnections or, furthermore, without interconnections. For these three different conditions, several numerical models using FEM via Abaqus software were simulated to obtain and compare the compression resistance. The results show that these built-up sections with fixed and sliding interconnections have very similar behavior to the results obtained with European Standard procedure, when considering equivalent areas and inertias for the built-up section. Also, it shows that this observation does not apply to the sections without interconnections. Comparative graphs of compression resistance curves were generated, as also some graphs that show the distribution of the compressive force between each member of the built-up section. Finally, a formulation for the design of built-up sections without interconnections along the tubes was proposed to avoid robust computational methods.

Resumo Neste trabalho é estudado o processo de projeto baseado em desempenho por meio do desenvolvimento de modelos paramétricos e algorítmicos, integrando análise estrutural ao design para a geração de estruturas geométricas complexas, com base em parâmetros de produção e montagem. Essa metodologia baseia-se no Modelo Performativo, em que a forma é gerada utilizando-se critérios de desempenho. Nessa abordagem o desenvolvimento de estruturas complexas só é possível pela reversão do processo de concepção da forma, cuja geração está atrelada aos parâmetros de geometria, material e carregamento. Assim, o engenheiro estrutural não participa apenas da fase de avaliação, mas também das fases iniciais do processo, criando um processo de pesquisa e produção de conhecimento comum entre os arquitetos e engenheiros. Para investigar essa abordagem, neste artigo é feita a concepção da estrutura de uma torre de energia eólica.

Abstract This paper presents a study based on the performance design process by using parametric and algorithmic models development. This study integrates the structural analysis and the design to generate complex geometric structures, based on manufacture and assembly parameters. The used methodology is based on the Performative Model, in which the structure shape is generated using performance criteria. In this perspective, the complex structures development is only possible by reverting de shape conception process, in which its generation is linked to the geometric, material and load parameters. Therefore, the structural engineer not only participates in the evaluation phase, but also in the early stages, creating an exploration and production process of common knowledge among architects and engineers. For the purpose of investigating this approach, this work presents the design of a conceptual lattice wind tower.