Dissertações de mestrado

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Navegando Dissertações de mestrado por Autor "Alves, Elcio Cassimiro"

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    ANÁLISE DE IMPACTOS AMBIENTAIS E TOPOLOGIA EM PROJETO ÓTIMO DE TRELIÇAS MISTAS DE AÇO E CONCRETO VITÓRIA 2022
    (Universidade Federal do Espírito Santo, 2022-08-26) Klein, Diego; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509; https://orcid.org/0000-0003-4180-5203; http://lattes.cnpq.br/; Calenzani, Adenilcia Fernanda Groberio; https://orcid.org/0000000209369950; http://lattes.cnpq.br/9959808218883879; Ferreira, Walnorio Graca; https://orcid.org/0000-0002-2079-6048; http://lattes.cnpq.br/9453786966994911; Melo, Antonio Macario Cartaxo de; https://orcid.org/; http://lattes.cnpq.br/2798137522735300
    The civil construction sector is one of the main responsible for the emission of CO2 into the atmosphere, mainly with regard to the manufacture of construction materials, which is why the search for structural solutions with less environmental impact has been a constant object of research in the area. In Brazil, the use of composite steel and concrete structures has grown significantly in recent decades due to factors such as resource rationalization, structure weight reduction and faster construction. In addition, given the competitiveness that the structural model of flat truss presents in relation to medium and large spans, it is necessary to expand the scope of research related to the design, verification and optimization of composite steel and concrete trusses. Thus, in this work, it was proposed the optimization of CO2 emission, via Genetic Algorithm (GA) and the Particle Dispersion Algorithm (PSO), of mixed steel and concrete trusses with tubular steel profiles considering topology variation (layout of the truss panels) and whether or not to fill the upper flange profile with concrete. The analyzes were carried out for the three most common truss models: Pratt, Howe and Warren. The dimensions of the profiles, the compressive strength of the slab concrete and the concrete filling the upper flange, the number of panels, the height of the truss and the choice of slab shape were considered as design variables. Numerical examples were evaluated to verify which are the elements that most impact the final CO2 emission of the structure, in addition to evaluating the effectiveness of the algorithms to obtain the optimal solution and the impacts on the final optimization when considering the concrete filling in the upper flange tube. . An analysis of the structure's collapse modes was carried out in order to verify which are the governing constraints of the problem. The results indicate that there is a reduction in the final emissions of the structure when the upper flange tube is filled in. Although it increases the final emission of the concrete, there is a considerable reduction of steel in the upper flange profile.
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    Otimização da geometria de telha-fôrma de aço colaborante para lajes mistas de aço e concreto
    (Universidade Federal do Espírito Santo, 2023-02-14) Loureiro, Mayane Cordeiro; Calenzani, Adenilcia Fernanda Groberio; https://orcid.org/0000000209369950; http://lattes.cnpq.br/9959808218883879; https://orcid.org/0000-0001-6330-9900; http://lattes.cnpq.br/8931090707093532; Lima, Luciano Rodrigues Ornelas de; Sousa Junior, João Batista Marques de; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
    The use of steel formwork incorporated into composite steel-concrete slabs stands out for contributing to sustainable development in civil construction. However, this construction system still has limited usage in Brazil, which may be due to the restricted availability of formwork geometries in the national market. As such, this study aims to determine the optimal steel geometry that results in the lowest steel consumption during manufacture of the composite slabs, taking into consideration the initial construction phase, in which the formwork is under the highest load demand. The Direct Strength Method (DSM) and the traditional Effective Width Method (EWM) are applied for designing the steel formwork during the construction phase, where the coldformed steel profile resists the applied forces independently. For DSM, the critical buckling moments are determined using the elastic stability analysis program CUFSM, via Finite Strip Methods. The solution of the optimization problem was implemented in MATLAB® using Particle Swarm Optimization and considering two design variables: the thickness and the bend angle of the formwork web. In addition, the proposed formulation was evaluated in the implementation phase of DSM and EWM. Numerical analyses are carried out on four different steel geometries currently available in the Brazilian market. The main results showed that the developed computational program was successful in finding optimal solutions for said geometries, as the optimization reduced steel consumption by an average of 21.6%. Thickness had a greater effect on the steel savings, and this variable decreases in the optimal solution, while the height and bend angle increase.