EM - Escola de Minas

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6

Notícias

A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.

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Resultados da Pesquisa

Agora exibindo 1 - 2 de 2
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    Optimized reinforcement distribution in reinforced concrete structures under plane stress state.
    (2022) Silva, Amilton Rodrigues da; Ladeira, Artur Hallack
    The strut-and-tie model is widely used for analysis and design of reinforced concrete structures. To apply this model, it is necessary to defne strut-and-tie systems that represent the fow of stresses generated in the analyzed structure. In many situations, this strut-and-tie model is defned through an evolutionary structural optimization (ESO) considering linear isotropic material. The results obtained from this model are not always satisfactory Query ID="Q1" Text="Please confrm the inserted city name and country name in afliations 1 and 2 are correct and amend if necessary." because of the nonlinear behavior of the concrete, mainly because of the great diference in the behavior under tension and compression. Because of this, an evolutionary algorithm is developed in this article to defne the optimized reinforcement distribution in reinforced concrete structures under plane stress state, considering the nonlinearity of the materials. This algorithm adopts the same principle as the ESO algorithm; however, it does not eliminate the mesh element that discretizes the analyzed domain, but it eliminates the reinforcement of the elements that do not meet an efciency criterion. A three-node triangular fnite element is used for nonlinear analysis of the reinforced concrete structure under plane stress state. The structure domain is discretized by this element, which can be of four types: with reinforcement in two fxed orthogonal directions, only in one direction, or without reinforcement. During the evolutionary process of the algorithm using a rejection criterion based on the level of reinforcement strain, the elements with reinforcement are changed to elements without reinforcement or with reinforcement in only one direction. Three practical applications were evaluated to verify the efciency of the algorithm proposed in this article. Two of them had their results compared with results provided in the literature, verifying the efciency of the proposed algorithm.
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    Multi-objective topology optimization using the Boundary Element Method.
    (2019) Simonetti, Hélio Luiz; Almeida, Valério da Silva; Neves, Francisco de Assis das; Greco, Marcelo
    This article aims to explore the application of an evolutionary optimization technique for multi-objective optimization problems using as criteria the minimization of von Mises maximum stress and minimization of the maximum growth of internal structural strain energy. To evaluate the overall effect on the optimal design configuration, due to the removal of inefficient material from the structure by using these two optimization criteria, a goal weighting scheme is adopted, whereby the weight factors emphasize and balance the stress and strain energy criteria. Also considered in this study was the method of the exponentially weighted criterion for multi-objective optimization and the Pareto optimal concept. Thus, a contribution is made to the study of these two methods in the structural optimization procedure using a linear analysis by the Boundary Element Method. Four examples are presented to demonstrate the ability of the proposed method to solve structural design problems using multi-objective optimization.