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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2 resultados
Resultados da Pesquisa
Item Thermohydraulic flow problem in unsaturated porous media : FDM computational model.(2020) Souza, Karla Baêta e; Nogueira, Christianne de LyraThe moisture and heat fluxes in undeformable unsaturated porous media involve the movement of water, air, and heat that are induced by thermal and pressure gradients to which the porous medium is subjected under environmental conditions. Herein, the flow of the liquid phase is governed by the advective flow due to the hydraulic gradient and by the convective heat transfer due to the thermal gradient. The flow of the gas phase is governed by the advective flow due to the pressure gradient and the nonadvective flow of dry air and water vapor diffusion. The heat transport can be carried out by conduction, convection, and advection due to the pressure gradient. The mathematical model includes the air mass conservation, water mass conservation, and thermal energy conservation equations. This paper presents a detailed computational model based on the finite difference method (FDM) for one-dimensional analysis of the flow problem of heat and moisture in undeformable unsaturated porous media. Verification examples involving unsaturated flow analysis in isothermal and nonisothermal conditions are presented, highlighting the importance of having a relatively simple computational model to analyze a very complex physical problem.Item Nonlinear equilibrium and stability analysis of axially loaded piles under bilateral contact constraints.(2015) Silveira, Ricardo Azoubel da Mota; Maciel, Felipe Vieira; Silva, Andréa Regina Dias da; Machado, Fernando Carlos Scheffer; Nogueira, Christianne de LyraThis paper presents a nonlinear stability analysis of piles under bilateral contact constraints imposed by a geological medium (soil or rock). To solve this contact problem, the paper proposes a general numerical methodology, based on the finite element meth-od (FEM). In this context, a geometrically nonlinear beam-column element is used to model the pile while the geological medium can be idealized as discrete (spring) or continuum (Winkler and Pas-ternak) foundation elements. Foundation elements are supposed to react under tension and compression, so during the deformation process the structural elements are subjected to bilateral contact constraints. The errors along the equilibrium paths are minimized and the convoluted nonlinear equilibrium paths are made tracea-ble through the use of an updated Lagrangian formulation and a Newton-Raphson scheme working with the generalized displace-ment technique. The study offers stability analyses of three prob-lems involving piles under bilateral contact constraints. The anal-yses show that in the evaluation of critical loads a great influence is wielded by the instability modes. Also, the structural system stiffness can be highly influenced by the representative model of the soil.