Otimização topológica de estruturas termoelásticas tridimensionais

This work presents an optimization technique based on structural topology optimization methods, TOM, designed to solve problems of thermoelasticity 3D. The presented approach is based on the adjoint method of sensitivity analysis unified design and is intended to loosely coupled thermomechanical problems. The technique makes use of analytical expressions of sensitivities, enabling a reduction in the computational cost through the use of a coupled field adjoint equation, defined in terms the of temperature and displacement fields. The TOM used is based on the material aproach. Thus, to make the domain is composed of a continuous distribution of material, enabling the use of classical models in nonlinear programming optimization problem, the microstructure is considered as a porous medium and its constitutive equation is a function only of the homogenized relative density of the material. In this approach, the actual properties of materials with intermediate densities are penalized based on an artificial microstructure model based on the SIMP (Solid Isotropic Material with Penalty). To circumvent problems chessboard and reduce dependence on layout in relation to the final optimal initial mesh, caused by problems of numerical instability, restrictions on components of the gradient of relative densities were applied. The optimization problem is solved by applying the augmented Lagrangian method, the solution being obtained by applying the finite element method of Galerkin, the process of approximation using the finite element Tetra4. This element has the ability to interpolate both the relative density and the displacement components and temperature. As for the definition of the problem, the heat load is assumed in steady state, i.e., the effects of conduction and convection of heat does not vary with time. The mechanical load is assumed static and distributed

Método de Otimização Topológica em Estruturas Tridimensionais

The topology optimization problem characterize and determine the optimum distribution of material into the domain. In other words, after the definition of the boundary conditions in a pre-established domain, the problem is how to distribute the material to solve the minimization problem. The objective of this work is to propose a competitive formulation for optimum structural topologies determination in 3D problems and able to provide high-resolution layouts. The procedure combines the Galerkin Finite Elements Method with the optimization method, looking for the best material distribution along the fixed domain of project. The layout topology optimization method is based on the material approach, proposed by Bendsoe & Kikuchi (1988), and considers a homogenized constitutive equation that depends only on the relative density of the material. The finite element used for the approach is a four nodes tetrahedron with a selective integration scheme, which interpolate not only the components of the displacement field but also the relative density field. The proposed procedure consists in the solution of a sequence of layout optimization problems applied to compliance minimization problems and mass minimization problems under local stress constraint. The microstructure used in this procedure was the SIMP (Solid Isotropic Material with Penalty). The approach reduces considerably the computational cost, showing to be efficient and robust. The results provided a well defined structural layout, with a sharpness distribution of the material and a boundary condition definition. The layout quality was proporcional to the medium size of the element and a considerable reduction of the project variables was observed due to the tetrahedrycal element

Desenvolvimento da célula base de microestruturas periódicas de compósitos sob otimização topológica

This thesis develops a new technique for composite microstructures projects by the Topology Optimization process, in order to maximize rigidity, making use of Deformation Energy Method and using a refining scheme h-adaptative to obtain a better defining the topological contours of the microstructure. This is done by distributing materials optimally in a region of pre-established project named as Cell Base. In this paper, the Finite Element Method is used to describe the field and for government equation solution. The mesh is refined iteratively refining so that the Finite Element Mesh is made on all the elements which represent solid materials, and all empty elements containing at least one node in a solid material region. The Finite Element Method chosen for the model is the linear triangular three nodes. As for the resolution of the nonlinear programming problem with constraints we were used Augmented Lagrangian method, and a minimization algorithm based on the direction of the Quasi-Newton type and Armijo-Wolfe conditions assisting in the lowering process. The Cell Base that represents the composite is found from the equivalence between a fictional material and a preescribe material, distributed optimally in the project area. The use of the strain energy method is justified for providing a lower computational cost due to a simpler formulation than traditional homogenization method. The results are presented prescription with change, in displacement with change, in volume restriction and from various initial values of relative densities.

Análise de estruturas de superfície delgadas axissimétricas via método dos elementos finitos com utilização de elemento retilíneo

The present work deals with the linear analysis of bi-dimensional axisymmetric structures, through development and implementation of a Finite Element Method code. The structures are initially studied alone and afterwards compatibilized into coupled structures, that is, assemblages, including tanks and pressure vessels. Examples are analysed and, in order to prove accuracy, the results were compared with those furnished by the analytical solutions

Avaliação da estrutura de tecidos técnicos como elemento reforçante em compósitos poliméricos sistema poliéster isoftálico

Materials known as technical textiles can be defined as structures designed and developed to meet specific functional requirements of various industry sectors, which is the case in automotive and aerospace industries, and other specific applications. Therefore, the purpose of this work presents the development and manufacture of polymer composite with isophthalic polyester resin. The reinforcement of the composite structure is a technical textile fabric made from high performance fibers, aramid (Kevlar 49) and glass fiber E. The fabrics are manufactured by the same method, with the aim of improving the tensile strength of the resulting polymer composite material. The fabrics, we developed some low grammage technical textile structures in laboratory scale and differentiated-composition type aramid (100%), hybrid 1 aramid fiber / glass (65/35%) and hybrid 2 aramid fiber / glass (85/15% ) for use as a reinforcing element in composite materials with unsaturated isophthalic polyester matrix. The polymer composites produced were tested in uniaxial tensile fracture surface and it´s evaluated by SEM. The purpose of this work characterize the performance of polymer composites prepared, identifying changes and based on resistance to strain corresponding to the mechanical behavior. The objectives are to verify the capability of using this reinforcement structure, along with the use of high performance fibers and resin in terms of workability and mechanical strength; verify the adherence of the fiber to the matrix and the fracture surface by electron microscopy scanning and determination of tensile strength by tensile test. The results indicate that, in a comparative study to the response of uniaxial tensile test for tensile strength of the composites and the efficiency of the low percentage of reinforcement element, being a technical textile fabric structure that features characteristic of lightness and low weight added in polymer composites

A argumentação como elemento discursivo na mídia digital: um estudo sobre o blog fatos e dados

This thesis studies the use of argumentation as a discursive element in digital media, particularly blogs. We analyzed the Blog "Fatos e Dados" [Facts and Data], created by Petrobras in the context of allegations of corruption that culminated in the installation of a Parliamentary Commission of Inquiry to investigate the company within the Congress. We intend to understand the influence that the discursive elements triggered by argumentation exercise in blogs and about themes scheduling. To this end, we work with notions of argumentation in dialogue with questions of language and discourse from the work of Charaudeau (2006), Citelli (2007), Perelman & Olbrechts-Tyteca (2005), Foucault (2007, 2008a), Bakhtin (2006) and Breton (2003). We also observe our subject from the perspective of social representations, where we seek to clarify concepts such as public image and the use of representations as argumentative elements, considering the work of Moscovici (2007). We also consider reflections about hypertext and the context of cyberculture, with authors such as Levy (1993, 1999, 2003), Castells (2003) and Chartier (1999 and 2002), and issues of discourse analysis, especially in Orlandi (1988, 1989, 1996 and 2001), as well as Foucault (2008b). We analyzed 118 posts published in the first 30 days of existence of the blog "Fatos e Dados" (between 2 June and 1 July 2009), and analyzed in detail the top ten. A corporate blog aims to defend the points of view and public image of the organization, and, therefore, uses elements of social representations to build their arguments. It goes beyond the blog, as the main news criteria, including the posts we reviewed, the credibility of Petrobras as the source of information. In the posts analyzed, the news values of innovation and relevance also arise. The controversy between the Blog and the press resulted from an inadequacy and lack of preparation of media to deal with a corporate blog that was able to explore the characteristics of liberation of the emission pole in cyberculture. The Blog is a discursive manifestation in a concrete historical situation, whose understanding and attribution of meaning takes place from the social relations between subjects that, most of the time, place themselves in discursive and ideological dispute between each other - this dispute also affects the movements of reading and reading production. We conclude that intersubjective relationships that occur in blogs change, in the form of argumentative techniques used, the notions of news criteria, interfering with scheduling of news and organization of information in digital media outlets. It is also clear the influence that the discursive elements triggered by argumentation exercise in digital media, trying to resize and reframe frames of reality conveyed by it in relation to the subject-readers. Blogs have become part of the scenario information with the emergence of the Internet and are able to interfere in a more effective way to organize the scheduling of media from the conscious utilization of argumentative elements in their posts

Simetria de invariância de escala discreta, log-periodicidade e singularidades em tempo finito

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Culinária do Seridó: um elemento da identidade territorial

This work aims to analyze the local cuisine as an element of territorial identity from Seridó Rio Grande do Norte State in the contemporaneousness - XXI century, where it takes place one motion, seemly contradictory, yet dialogical, in the way of eating locally is modified by food diversity and yet is lauded as an element of resistance, that is, of identification. Based on the perspective that groups go over time outlining on the territory their eating cultural characteristics, we have noticed that the spatiality from the local cuisine has happened during the territorial structuring process, being susceptible to the social, economical and technological changes, that hover over this space. On the unfolding days it was created a whole semiology around the cookery , incorporating to its territory of living, symbols, images, knowledge, tastes, feelings and smells that legitimate a way of being, better saying, of eating. But not all of the plates that congregate these aspects, only the oldest, the most emblematic. Within the diverse intercrossing of culture at Seridó region, they are the ones that maintain the vinculum from the group with its culture and with its territory, reminding what they are, or at least what they were, conferring them a legitimacy before those to whom they relate. The cookery from the Seridó region, this way is a cultural geo-symbol that turn this space significant and visible, for ordering the inside characteristics from the group before the new socio-cultural models present in the territory

A linguagem audiovisual do cinema como elemento integrador da arte e ciência na formação cultural dos professores de ciências e matemática

This work aims to study about the importance of cinema for cultural and professional training of teachers of Natural Sciences and Mathematics. The educational potential of cinema is emphasizing by different authors, which also reveal the teachers' training gap in this issue (media). In this study, we defend the audiovisual language of cinema as an integrating element of Arts and Science for cultural and professional training of teachers. This subject has been developed by different authors, in which the emphasis has been the importance of intelligent dialogue with the world. Specifically, the training of science teachers and mathematics, by the approach of Cinema in its formation, It envisions the possibility of minimizing the dichotomy between humanistic and scientific training, already much discussed by some researchers. Educational products contribute to an effective experience and reflection on the cultural and educational role of the Seventh Art. Considering the Cinema as a possible "bridge" between the two cultures (scientific culture and humanistic culture) and promoting ownership of audiovisual language in teacher training It was accomplished the I Exhibition - Cultural Spring: Cinema and Science Education in UFRN. The production of the booklet "Topics of History, Language and Art of Cinema for Science and Mathematics Teachers," and its application in a short course in the XXI National Symposium on Physics Teaching also aimed to contribute to the approximation of Science and Art in training teachers.

Projeto SB Brasil 2010: elemento estratégico na construção de um modelo de vigilância em saúde bucal

O projeto começou a ser pensado no âmbito do Comitê Técnico Assessor (CTA) em Vigilância em Saúde Bucal do Ministério da Saúde desde abril de 2009. Foi submetido à consulta pública durante o mês de junho de 2009, resultando em uma participação significativa de diversos setores em seu processo de construção. Desde então, foi formado um Grupo Gestor que, por intermédio de oito Centros Colaboradores localizados nas diversas regiões do país, tem conduzido o projeto a partir de oficinas de trabalho nos estados e treinamento das equipes de campo.

Projeto SB Brasil 2010: elemento estratégico na construção de um modelo de vigilância em saúde bucal

O projeto começou a ser pensado no âmbito do Comitê Técnico Assessor (CTA) em Vigilância em Saúde Bucal do Ministério da Saúde desde abril de 2009. Foi submetido à consulta pública durante o mês de junho de 2009, resultando em uma participação significativa de diversos setores em seu processo de construção. Desde então, foi formado um Grupo Gestor que, por intermédio de oito Centros Colaboradores localizados nas diversas regiões do país, tem conduzido o projeto a partir de oficinas de trabalho nos estados e treinamento das equipes de campo.