http://repositorio.ufc.br/handle/riufc/425 2026-04-05T13:55:41Z 2026-04-05T13:55:41Z Machado, Wanderson Gonçalves Neves, Francisco de Assis das Sousa Júnior, João Batista Marques de http://repositorio.ufc.br/handle/riufc/69416 2023-12-06T14:09:02Z 2017-01-01T00:00:00Z

Título: Parametric modal dynamic analysis of steel-concrete composite beams with deformable shear connection Autor(es): Machado, Wanderson Gonçalves; Neves, Francisco de Assis das; Sousa Júnior, João Batista Marques de Abstract: Composite structural elements of steel-concrete began to be used only in 1960 after the development of methods and constructive dispositions that ensured the functionality of these two materials together. In order to verify the importance of the participation of the axial mode in the frequency spectrum of the free vibration problem in composite beams with deformable shear connection, several analyses for 4 different boundary conditions and stiffness connection variation were performed. The analysis of the problem was carried out by development and computational implementation of a finite element for composite beams with partial interaction in the longitudinal direction applied to the problem of free vibrations. The solutions to this problem in the literature are scarce, and project recommendations are simplified. The results show that the finite element exhibits an excellent performance compared with the analytical results and as the axial mode has a high modal contribution, despite the boundary condition and stiffness connection. Tipo: Artigo de Periódico

2017-01-01T00:00:00Z Saraiva, Raisse Layane de Paula Barros Neto, José de Paula Maués, Luiz Maurício Furtado http://repositorio.ufc.br/handle/riufc/68326 2023-12-06T14:07:22Z 2021-01-01T00:00:00Z

Título: Proposta de modelo estatístico para hierarquização do resultado de pesquisas de satisfação de clientes Autor(es): Saraiva, Raisse Layane de Paula; Barros Neto, José de Paula; Maués, Luiz Maurício Furtado Abstract: Meeting customer requirements is crucial for any company or industry, since delivering to customers the products they need or desire is their reason for existing. In housing projects, understanding those requirements and translating them into design attributes is a way to achieve customer satisfaction and ensure a competitive edge to the company. In order to do that, different methods focused on the qualitative aspects have been used. However, those methods have proven to be limited with regards to ensuring the quality of building products. With the purpose of proposing a method to build a hierarchy of the requisites resulting from customer satisfaction surveys, based on quantitative aspects, this study analysed a databank formed by customer satisfaction surveys in housing developments with different economic standards. The study applied measures of central tendency and dispersion, reliability tests by means of the Cronbach's Alpha and factor analysis. The results show that the main tool to help meeting the aims is factor analysis, with the constructive aspects related to size, quality, functionality and comfort more likely to provide satisfaction to customers. Tipo: Artigo de Periódico

2021-01-01T00:00:00Z Silva, Leonária Araújo Araújo, Lucas Benício Rodrigues Bezerra, Ana Karoliny Lemos Murta, Arthur Hermont Fonseca Babadopulos, Lucas Feitosa de Albuquerque Lima Medeiros Júnior, Marcelo Silva http://repositorio.ufc.br/handle/riufc/68241 2023-12-06T14:08:57Z 2022-01-01T00:00:00Z

Título: Modelagem preditiva de propriedades mecânicas em concretos reforçados com fibra de aço utilizando redes neurais artificiais Autor(es): Silva, Leonária Araújo; Araújo, Lucas Benício Rodrigues; Bezerra, Ana Karoliny Lemos; Murta, Arthur Hermont Fonseca; Babadopulos, Lucas Feitosa de Albuquerque Lima; Medeiros Júnior, Marcelo Silva Abstract: The aim of this paper was to estimate the mechanical properties essential to the design of concrete structures through a reliable prediction model of the compressive, tensile and flexural strengths of concrete steel fiber reinforced concrete (CFRC) using Artificial Neural Networks (ANN), and also to evaluate the influence of the fiber content on these properties. The study used a database with 57 experimental studies from the literature, implementing a neural network model with 12 input variables, 1 output and 2 hidden layers with 16 neurons. The results obtained were a mean square error (MSE) of 22.63, 0.08 and 0.80, and a mean absolute error (MAE) of 3.64, 0.24 and 0.74, respectively, for the compressive, tensile and flexural strengths. The sensitivity analysis showed that there was a considerable increase in tensile and flexural strengths with the use of fibers, which was expected. The results confirmed the model's ability to reliably reproduce the mechanical properties of the CFRC. Tipo: Artigo de Periódico

2022-01-01T00:00:00Z Cirino, Miguel Adriano Gonçalves Cabral, Antonio Eduardo Bezerra Silva, David Alison Araújo Sampaio, Kalil Nobrega Hissa http://repositorio.ufc.br/handle/riufc/68070 2023-12-06T14:09:05Z 2021-01-01T00:00:00Z

Título: Caracterização e avaliação da atividade pozolânica das cinzas provenientes da queima de carvão mineral das termelétricas do Pecém, Ceará, Brasil Autor(es): Cirino, Miguel Adriano Gonçalves; Cabral, Antonio Eduardo Bezerra; Silva, David Alison Araújo; Sampaio, Kalil Nobrega Hissa Abstract: The trend towards stabilization of coal consumption, observed until 2019, was interrupted due to the Sars-Cov 2 pandemic that affected energy production based on mineral coal, reducing the world demand for this product. The burning of mineral coal for energy production in thermal power plants generates large amounts of waste, such as light ash (fly ash), from electrostatic processes and background ash (botton ash), from desulfurization processes of the chimney gas (Flue Gas Desulfurization - FGD). In many residues, they are stored in open air deposits, becoming a potential risk to the environment and the surrounding ecosystems. In order to improve understanding of the characteristics of these residues, we sought to characterize light ash (CV1) and bottom ash (CV2), residues from the Pecém I and II thermoelectric plants, located in the state of Ceará / Brazil, regarding chemical and physical parameters by means of chemical composition tests by FRX (X-Ray Fluorescence) and EDS (Dispersive Energy Spectroscopy), moisture content, loss to fire, insoluble residue content, specific mass, fineness by air permeability method, granulometric characterization, microstructure evaluation by SEM (Scanning Electron Microscopy), thermogravimentation, determination of the mineralogy phases by XRD (X-Ray Diffraction) and evaluation of pozzolanic activity. It was evidenced that CV1 has characteristics compatible with type C fly ash and pozzolanic activity. For CV2 ash, it was observed that the chemical requirements for pozzolanic activity were not met, also presenting high levels of sulfur trioxide and crystalline phases such as Calcite, from the FGD desulfurization process. In both cases, the ashes can be used in cementitious compounds, as long as they are compatible with the characteristics presented, thus enabling the reduction and accumulation of material in the plants, reducing the risks to the environment. Tipo: Artigo de Periódico

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