34 resultados para Análise de elemento finito

em Universidade Federal do Rio Grande do Norte(UFRN)


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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

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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

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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.

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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

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COSTA, Roberta Kaliny de Souza ; ENDERS, Bertha Cruz ; MENEZES, Rejane Maria Paiva de . Trabalho em equipe em saúde: uma análise contextual. Ciência, Cuidado e Saúde, v. 7, p. 530-536, 2008.

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VARELA, M.L. et al. Otimização de uma metodologia para análise mineralógica racional de argilominerais. Cerâmica, São Paulo, n. 51, p. 387-391, 2005.

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The building envelope is the principal mean of interaction between indoors and environment, with direct influence on thermal and energy performance of the building. By intervening in the envelope, with the proposal of specific architectural elements, it is possible to promote the use of passive strategies of conditioning, such as natural ventilation. The cross ventilation is recommended by the NBR 15220-3 as the bioclimatic main strategy for the hot and humid climate of Natal/RN, offering among other benefits, the thermal comfort of occupants. The analysis tools of natural ventilation, on the other hand, cover a variety of techniques, from the simplified calculation methods to computer fluid dynamics, whose limitations are discussed in several papers, but without detailing the problems encountered. In this sense, the present study aims to evaluate the potential of wind catchers, envelope elements used to increase natural ventilation in the building, through CFD simplified simulation. Moreover, it seeks to quantify the limitations encountered during the analysis. For this, the procedure adopted to evaluate the elements implementation and efficiency was the CFD simulation, abbreviation for Computer Fluid Dynamics, with the software DesignBuilder CFD. It was defined a base case, where wind catchers were added with various settings, to compare them with each other and appreciate the differences in flows and air speeds encountered. Initially there has been done sensitivity tests for familiarization with the software and observe simulation patterns, mapping the settings used and simulation time for each case simulated. The results show the limitations encountered during the simulation process, as well as an overview of the efficiency and potential of wind catchers, with the increase of ventilation with the use of catchers, differences in air flow patterns and significant increase in air speeds indoors, besides changes found due to different element geometries. It is considered that the software used can help designers during preliminary analysis in the early stages of design

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The research that led to this dissertation adopted a set of scenic/ideological aspects inherent to the productions of the Culture Industry as its object of research. The intellectual output of Theodor W. Adorno and Max Horkheimer underscored the approaches on this subject, since it provides the same set of scenic/ideological features to be explored because, according to the authors, scenes produced by the culture industry are linked to the dominant ideology, since they act in favor of maintaining the status quo. The first objective was the definition this set of features inherent to the scene produced by the culture industry, through the exploration of literature produced by Adorno and Horkheimer, so it was possible to define a set composed of nine elements: Construction of characters as characteristic types; Stereotypes; Naturalization of Stereotyped language; Simplistic playwriting; Reuse dramatic formula; Love and sexuality as themes of plots; Utilization of tragic element; Objetive representation; Approximation of fiction and reality. The second goal was the analysis of scene produced by the culture industry nowadays, so that it was possible to verify if any scenic/ideological aspects indicated by Adorno and Horkheimer in the mid-twentieth century were present among the productions from this beginning of the twenty-first century. Through the analysis of three soap operas produced in Brazil in 2012, it was found that the nine scenic/ideological aspects as indicated by Adorno and Horkheimer appeared in the observed productions. Additionally, a new scenic/ideological feature, not indicated by Adorno and Horkheimer is present: the merchandising

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This work demonstrates the importance of using tools used in geographic information systems (GIS) and spatial data analysis (SDA) for the study of infectious diseases. Analysis methods were used to describe more fully the spatial distribution of a particular disease by incorporating the geographical element in the analysis. In Chapter 1, we report the historical evolution of these techniques in the field of human health and use Hansen s disease (leprosy) in Rio Grande do Norte as an example. In Chapter 2, we introduced a few basic theoretical concepts on the methodology and classified the types of spatial data commonly treated. Chapters 3 and 4 defined and demonstrated the use of the two most important techniques for analysis of health data, which are data point processes and data area. We modelled the case distribution of Hansen s disease in the city of Mossoró - RN. In the analysis, we used R scripts and made available routines and analitical procedures developed by the author. This approach can be easily used by researchers in several areas. As practical results, major risk areas in Mossoró leprosy were detected, and its association with the socioeconomic profile of the population at risk was found. Moreover, it is clearly shown that his approach could be of great help to be used continuously in data analysis and processing, allowing the development of new strategies to work might increase the use of such techniques in data analysis in health care

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Trabalho sobre a concretização dos direitos fundamentais pela jurisdição constitucional, mostrando a importância da interpretação da Constituição para a obtenção da eficácia de tais direitos. Desenvolve-se a pesquisa a partir da explicação histórica sobre o constitucionalismo moderno, que implantou o Estado Liberal de Direito e as constituições escritas, e no qual encontra a jurisdição constitucional o seu embasamento cultural e a sua justificação histórica. Verifica-se que a origem da jurisdição constitucional assenta-se no controle da constitucionalidade das leis e atos normativos do poder público, fundado no princípio da supremacia da Constituição. Destaca-se o realce dado pela teoria material da Constituição à normatividade dos princípios constitucionais, tecendo considerações em torno da classificação das normas constitucionais em regras e princípios. Remarca o trabalho que o controle da constitucionalidade pode ser formal ou material, apresentando esta última modalidade uma conotação acentuadamente política, já que, por ele, a aferição da compatibilidade da norma infraconstitucional é feita com o conteúdo material da Constituição. A função primacial da jurisdição constitucional é tutelar os direitos fundamentais, especialmente os das minorias sociais. Tal função sobreleva-se até mesmo contra textos legislativos produzidos por maiorias eventuais, pois o princípio da supremacia da Constituição prevalece sobre a regra da maioria vigente nos regimes democráticos. Comprova-se que a concepção substancialista, adotada para definir os contornos funcionais da jurisdição constitucional, propõe uma maior intervenção desta na apreciação dos casos que lhe são submetidos. Salienta-se que, no Estado Democrático de Direito, derivado da aglutinação do Estado Liberal com o Estado Social e acrescida de um elemento novo voltado à transformação da realidade social, a jurisdição constitucional passa a levar em conta, com mais atenção e destaque, os princípios constitucionais e a sincronia do ordenamento constitucional com a sociedade por ele ordenada. Realça também o estudo que a atuação da jurisdição constitucional, segundo a ideologia democrática defendida pelo Estado Democrático de Direito, tem logrado obter uma sociedade mais justa, e que a comprovação histórica é francamente favorável ao seu ativismo judicial. Os direitos fundamentais dificilmente se dissociam da democracia, que lhes garante a eficácia pela limitação e visibilidade do exercício do poder, traços políticos que constituem a nota típica dos regimes democráticos. Mesmo que os direitos fundamentais tenham tido um caráter pré-estatal como preconizado pelo jusnaturalismo, são eles normas, e não valores, pois tão logo sejam positivados pela Constituição eles se tornam direitos vigentes. Assevera a pesquisa que os métodos concretistas de interpretação constitucional mostram-se mais adequados à obtenção da eficácia da Constituição, pela importância que os elementos objetivos, relacionados com o contexto material da norma, assumem no seu processo de aplicação e interpretação. Conclui-se ser essencial que os operadores e estudiosos do Direito se conscientizem de que a interpretação constitucional deve assumir uma feição principiológica e concretista, de modo a ser obtida a máxima eficácia possível das normas constitucionais, especialmente as de direitos fundamentais, acentuando-se mais a necessidade de um Tribunal Constitucional, cuja criação no Brasil constitui ainda tema polêmico entre os doutrinadores

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As substâncias entorpecentes acompanham a humanidade desde o início da civilização. No entanto, várias delas foram consideradas proscritas ao longo do tempo. Seu combate foi inaugurado na comunidade internacional a partir do começo do século XX. No início, tinha o condão eminentemente moral, porquanto a proibição encerrava, por princípio, a proteção da ética ameaçada pelo padrão desviado do consumo de estupefacientes. Na década de 1970, a guerra contra as drogas, expressão cunhada nesse período, evoluiu para se tornar o meio pelo qual o consumo seria mitigado. Dez anos mais tarde, ante à impossibilidade de sucumbir o narcotráfico, passou a ser um fim em si mesma o novo argumento para os esforços militares dos Estados Unidos da América. A criminalização das substâncias entorpecentes consideradas ilícitas é fundamento jurídico da guerra contra as drogas. Esse modelo proibicionista encontra argumento no direito penal do inimigo, segundo o qual o Estado pode, em situações que exponham a coletividade a grave perigo, negar à determinada categoria de criminosos (os inimigos) as garantias inerentes ao direito penal, cabendo-lhes apenas a coação estatal. Mesmo tendo consumido trilhões de dólares, encarcerado aos milhões e custado a vida de milhares de pessoas, pode-se dizer que a guerra contra as drogas não reduziu a oferta e o consumo de substâncias entorpecentes consideradas ilícitas, nem mitigou os danos delas decorrentes pelo contrário, tornou-se um problema de segurança pública. Assim, impõe-se a verificação da constitucionalidade da norma penal que fundamenta a guerra contra as drogas, sob ponderação do princípio da proporcionalidade. Referido postulado cobra que a norma seja adequada, cumprindo a finalidade pretendida, necessária, não havendo meio menos gravoso à obtenção do mesmo fim, e proporcional, estrito senso, que a sanção imposta ao indivíduo seja equivalente ao dano que se quis prevenir. Em matéria penal há de se incluir um outro elemento, a ponderar se as consequências da proibição em matéria penal, por si só, são mais graves que os consectários dos fatos que se pretendem proibir - exige-se que a lei seja socialmente menos ofensiva. A norma penal que fundamenta a guerra contra as drogas não se mostrou hábil a mitigar os danos sociais delas decorrentes sendo, por isso, inadequada. Existem meios alternativos à criminalização mais eficientes à esse objetivo, pelo que se faz desnecessária. Na medida em que estupefacientes mais nocivos à coletividade são considerados lícitos, a criminalização de drogas menos danosas se mostra desproporcional. E, uma vez que dela resultam graves danos à sociedade, não atende ao critério da menor ofensividade social. É, portanto, inconstitucional

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The conceptions of the judicial function, the process and the factors of legitimacy of the norm of decision are changed according to the model of State (liberal, social democratic and constitutional). The right of access to justice, likewise, follows the ideals present in constitutional movements experienced in different historical moments. The deficit of legitimacy of the judiciary is recurring subject of study in the doctrine, especially in the face of democratic standards that permeate the current paradigm of state. Under the process law, the essential element for the distinction of the states based on the rule of law (formal and material) and the democratic constitutional state lies in the democratic guarantee of participation to the litigants in the process of elaborating the norm of decision. The concern about the participatory democracy and the concretion of fundamental rights has as presupposition the conception of popular sovereignty. Keeping this effort in mind, the civil procedure cannot be oblivious to such considerations, especially when it justifies its constitutional conformation from the institutionalization of discourse within the procedural field (democratic principle) and of the democratization of access to justice, leading to the necessary contestation of the theory of instrumentality of the process. The democratic prospects of civil procedure and the concern about the legitimacy of the rule of decision cannot be moved away from the analysis of the judicial function and the elements that influence the legal suit s progress. The computerization of the judicial process entails extensive modification in the way the judicial function is developed, in view of automation of activities held, of the eliminating of bureaucratic tasks, manual and repetitive, and of streamlining the procedure. The objective of this study is to analyze the dogmatic changes and resulting practices from the implementation of the Judicial Electronic Process (JEP), prepared by the National Council of Justice, under the parameters of procedural discourse and democratic access to justice. Two hypotheses are raised, which, based on a bibliographic-documentary, applied and exploratory research, are contested dialectically. The expansion of publicity of procedural acts and the facilitating of communication and practice of such acts are elements that contribute to the effective participation of the recipients of the norm of decision in its making process and, therefore, the democratic principle in the procedural field. Ensuring access (to the parts) to the case files and reasonable duration of the process along with the preservation of its founding principles (contradictory, legal defense and isonomy) are essential to ensure democratic access to justice within the virtual system

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This paper aims to review traditional concepts inherent to the general theory of the state and human rights, relating to the legal situation of foreign, understood as the subject of rights, especially when the is case of compulsory legal imposition of exit from national territory. After the serious violations during the Second World War and the importance acquired by the International Law of Human Rights, values as dignity, justice and equality are enshrined in the legal system and its respect required beyond the boundaries of any country. The creation of an international community, which is governed by rules that its members are subordinated, without distinction, as well as state - based on volunteerism, become inspired by one principled nature of these new concepts required of Global Society, as well as the adoption, influenced by neoconstitutionalism, to the model of State Constitutional rule of law, are opposed to the idea of state sovereignty connected to a superiority, absolute and unlimited power which recognizes no other above it, not even the basic principles or axioms that must govern the relationships internally. So looks for a concept of state that includes all the requirements of a democratic society, that have the people as the power holder, understanding that state element has undergone a relativization, because had to adapt to the contemporary values applicable to the individual, inserting in its concept, the indispensable obligation to protect the inalienable rights of citizens, regardless of with whom he have legal and political bond of nationality. It happens that, to consecrate these privileges to individuals, which, because they contain reference to values with supranational characteristics, are very abstract and are in constant collision course with internal rules, making it difficult to reconcile, it will use hermeneutics of human rights, due mainly to international courts, correlated with constitutional exegesis, in particular, legal principiologia, using, among others, the principles of reasonableness and proportionality, the systematic interpretation of the Constitution and international legal standards. Thus, it seek to enshrine the common foundation of all law , the link between the systems, namely, the dignity of human beings. Finally, it will see if Brazilian jurisdiction, through case studies, is tuned in line with these new paradigms, and in line with the International Bill of Human Rights, the Federal Constitution, the values and principles she hired

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The right against self-incrimination is a fundamental right that works in the criminal prosecution, and therefore deserves a study supported by the general theory of criminal procedure. The right has a vague origin, and despite the various historical accounts only arises when there is a criminal procedure structured that aims to limit the State´s duty-power to punish. The only system of criminal procedure experienced that reconciles with seal self-incrimination is the accusatory model. The inquisitorial model is based on the construction of a truth and obtaining the confession at any cost, and is therefore incompatible with the right in study. The consecration of the right arises with the importance that fundamental rights have come to occupy in the Democratic Constitutional States. In the Brazilian experience before 1988 was only possible to recognize that self-incrimination represented a procedural burden for accused persons. Despite thorough debate in the Constituent Assembly, the right remains consecrated in a textual formula that´s closer to the implementation made by the Supreme Court of the United States, known as "Miranda warnings", than the text of the Fifth Amendment to the U.S. Constitution that established originally the right against self-incrimination with a constitutional status. However, the imprecise text does not prevent the consecration of the principle as a fundamental right in Brazilian law. The right against self-incrimination is a right that should be observed in the Criminal Procedure and relates to several of his canons, such as the the presumption of not guilty, the accusatory model, the distribution of the burden of proof, and especially the right of defense. Because it a fundamental right, the prohibition of self-incrimination deserves a proper study to her constitutional nature. For the definition of protected persons is important to build a material concept of accused, which is different of the formal concept over who is denounced on the prosecution. In the objective area of protection, there are two objects of protection of the norm: the instinct of self-preservation of the subject and the ability to self-determination. Configuring essentially a evidence rule in criminal procedure, the analysis of the case should be based on standards set previously to indicate respect for the right. These standard include the right to information of the accused, the right to counsel and respect the voluntary participation. The study of violations cases, concentrated on the element of voluntariness, starting from the definition of what is or is not a coercion violative of self-determination. The right faces new challenges that deserve attention, especially the fight against terrorism and organized crime that force the development of tools, resources and technologies about proves, methods increasingly invasive and hidden, and allow the use of information not only for criminal prosecution, but also for the establishment of an intelligence strategy in the development of national and public security

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The bidimensional periodic structures called frequency selective surfaces have been well investigated because of their filtering properties. Similar to the filters that work at the traditional radiofrequency band, such structures can behave as band-stop or pass-band filters, depending on the elements of the array (patch or aperture, respectively) and can be used for a variety of applications, such as: radomes, dichroic reflectors, waveguide filters, artificial magnetic conductors, microwave absorbers etc. To provide high-performance filtering properties at microwave bands, electromagnetic engineers have investigated various types of periodic structures: reconfigurable frequency selective screens, multilayered selective filters, as well as periodic arrays printed on anisotropic dielectric substrates and composed by fractal elements. In general, there is no closed form solution directly from a given desired frequency response to a corresponding device; thus, the analysis of its scattering characteristics requires the application of rigorous full-wave techniques. Besides that, due to the computational complexity of using a full-wave simulator to evaluate the frequency selective surface scattering variables, many electromagnetic engineers still use trial-and-error process until to achieve a given design criterion. As this procedure is very laborious and human dependent, optimization techniques are required to design practical periodic structures with desired filter specifications. Some authors have been employed neural networks and natural optimization algorithms, such as the genetic algorithms and the particle swarm optimization for the frequency selective surface design and optimization. This work has as objective the accomplishment of a rigorous study about the electromagnetic behavior of the periodic structures, enabling the design of efficient devices applied to microwave band. For this, artificial neural networks are used together with natural optimization techniques, allowing the accurate and efficient investigation of various types of frequency selective surfaces, in a simple and fast manner, becoming a powerful tool for the design and optimization of such structures