Orientador: Haroldo de Mayo Bernardes / Banca: Antonio Anderson da Silva Segantini / Banca: Selmo Chapira Kuperman / Resumo: Diante dos vários casos registrados de anomalias surgidas em concretos de diferentes estruturas devidas às reações deletérias do tipo álcali-agregado (RAA), pesquisadores de todo o mundo têm buscado conhecer melhor o problema, entender seu mecanismo e caracterizar estruturas já afetadas. Realizou-se no presente trabalho um estudo de caso sobre a Tomada d'água (TA) da UHE Jaguari, visando estimar a expansibilidade do concreto dessa estrutura e a reatividade de agregados provenientes da região. Para isto, foram analisados testemunhos extraídos da TA por meio de ensaios de expansão, análises químicas e microestruturais, e um concreto com traço reconstituído em laboratório, reproduzindo o traço utilizado na construção da TA, avaliando a resistência mecânica, a propriedade elástica e a permeabilidade. Realizouse um estudo em separado dos agregados coletados da região (enrocamento da barragem, pedreira comercial e testemunho de sondagem da rocha de fundação da TA) por se tratar de materiais que provavelmente têm a mesma procedência que o empregado na barragem. Foram realizadas análises químicas, usando técnicas como difração de raios X e infravermelho, bem como análises do potencial expansivo, por meio de barras de argamassa e prismas de concreto, conforme as normas NBR 15577-4 e NBR 15577-6, respectivamente. Este conjunto de informações constitui uma contribuição para que venha a ser feita uma avaliação da real situação da estrutura no tocante à RAA, estabelecendo parâmetros iniciais para estimar em qual estágio de expansão a estrutura se encontra. / Abstract: Ahead of some registered cases of anomalies appeared in concrete of different structures due to the deleterious reactions of the alkali-aggregate reaction (AAR) type, researchers of all over the world have studied this problem, to understand its mechanism and to characterize structures which were already affected. In the present work, a characterization of the concrete used in this dam and a study of residual expansion obtained from extracted cores was performed. The case study was the intake of Jaguari Hydra Power plant, because it presents cracks that are characteristic of alkali-aggregate reaction. Tests were made on the same core of Jaguari Hydra Power Plant and in concrete from laboratory, using a local aggregate in order to evaluate: the strength, the elastic property, the permeability and the expansibility; as well as, chemical and micro structural analysis. Another study was made with aggregate collected from the rockfill of the dam, because this aggregate probably has the same origin that the one which were used in the dam construction and collected from soundings of the foundation rock of intake structure of Jaguari Power plant. This study contemplated chemical analysis, using techniques such as X-ray diffraction and infra-red ray, as well as analysis of the expansive potential in mortar bars and concrete prisms, through method NBR 15577-4 e NBR 15577-6, respectively. All this information will be useful to establish initial parameters and estimate what is the stage of the structure expansion due to alkali-aggregate reaction. / Mestre

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os recentes desastres ocorridos no país, como o rompimento da adutora em Campo Grande e os desastres relacionados às enchentes urbanas, mostram a necessidade de desenvolvimento de pesquisas científicas que auxiliem na compreensão e no dimensionamento das estruturas projetadas para atender a demanda da população. Os métodos analíticos e experimentais mais utilizados possuem algumas limitações de ordem teórica ou prática. Por outro lado, os métodos numéricos, capazes de simular etapas construtivas e envolver materiais com diferentes modelos constitutivos numa mesma análise, buscam atender às necessidades práticas dos projetos de geotecnia e, ao mesmo tempo, complementam os modelos analíticos e experimentais. Nesse trabalho foram realizadas comparações entre resultados obtidos em ensaios experimentais e resultados extraídos do modelo computacional, buscando aumentar a compreensão sobre a interação solo-estrutura em relação à distribuição de tensões mobilizadas e aos deslocamentos e deformações provocados. A simulação numérica foi feita com a utilização do PLAXIS/3D, software de análise geotécnica baseado no método dos elementos finitos. Os ensaios foram confeccionados na Escola de Engenharia de São Carlos/USP por Costa (2005) e envolveram dutos enterrados submetidos à perda de apoio ou elevação localizada. O estudo experimental foi realizado através de modelos físicos compostos por um maciço de areia pura, contendo um tubo repousando sobre um alçapão no centro do vão. Os modelos físicos foram equipados com instrumental capaz de medir as deflexões e as deformações específicas ao longo do duto, além das tensões totais no maciço de solo circundante e na base do equipamento. / Recent disasters that occurred in this country, like the failure of a pipeline in Campo Grande and others disasters related to urban flooding, show us the need for developing scientific researches that help us to understand the behavior of these structures and to design them to serve the population. Analytical and experimental methods have some theoretical and practical limitations. On the other hand, numerical methods are capable to simulate staged constructions and to analyze together materials with different constitutive models, supplying practical necessities of geotechnical projects and complementing analytical and experimental models. In this dissertation comparisons between experimental results and numerical results have been made, trying to increase the comprehension about the interaction of soil and pipe with respect to mobilized stress distribution, displacements and strains. The numerical modeling was performed on PLAXIS 3D software, based on Finit Elements Method. The experimental test was made by Costa (2005) at São Carlos Engineering School/USP and involved buried pipes undergoing loss of support or elevation in a localized region along its length. Tests have been performed with physical models comprising dry and pure dry sand and a tube resting on a rigid trapdoor base located at the center of its length. The models were equipped with devices for measuring deflections and strains in the pipe, and total stresses in soil mass and in the lower boundary of the model.

No description available.

The literature review shows that gender inequality in computer use exists today. The inequality begins at birth with society giving boys and girl's roles that they have to play. One possible solution to gender inequality in computer use is to put a gender equity program in place at public schools. Such a program would have to be woven into teaching practices and school activities to strengthen girls' confidence and their ability to achieve in computers.

The goal of the thesis is wear analysis of cutting inserts used for machining 42CrMo4 steel. Theoretical part of the thesis contains comparison of turning and milling machining processes, machining methods for ball screws made of 42CrMo4 and description of experimental methods of tool wear analysis. Experimental part of thesis contains methodology of cutting inserts wear measurement for chosen machining method. The following testing is focused on cutting insert wear as well as workpiece surface analysis. Thesis is finished with processing of measured data and overall evaluation of achieved results.

The thesis deals with the wear of replaceable inserts during the turning of structural hardened steel. The theoretical part describes a brief characteristic of turning technology, force loading on tools and tools used in turning. Moreover, it contains an analysis of the chemical composition of the machined material, its microstructure and microhardness. Machines and equipment used for the experiment and their specifications. The experimental part of the thesis describes the method of measuring and evaluating of tool wear, followed by the cutting tests themselves, documenting of the result and their evaluation. The conclusion of the thesis is the processing of measured data, the evaluation of achieved results and the proposal of further steps to improve the process.

This diploma thesis is focused on the implementation of the educational role of the experimental station for measuring the effectiveness of gears. The proposed laboratory task "Experimental measurement of the effectiveness of gears" is intended to familiarize students with the basic principles of gears and especially highlight the issue of the effectiveness of gears. In this presented thesis, it is also suggested the possibility of expanding the educational use of the experimental station. This extension deals with vibration diagnostics of frequencies of gears.

Doctorat en sciences psychologiques / info:eu-repo/semantics/nonPublished

No description available.

In der vorliegenden Arbeit wird eine Methodik zur Entwicklung mechanischer Simulationen der Interaktion Sportler-Sportgerät-Umwelt zur Untersuchung der Funktionalität von Sportgeräten konzipiert und vorgestellt. Die mechanische Simulation ist die gegenständliche Nachbildung spezieller Teilaspekte des Sportlers, z.B. der Körperform, der Trägheitseigenschaften, der Masse, der Interaktionskräfte zur Umwelt oder charakteristischer Bewegungsabläufe zum Zweck der Durchführung gezielter Experimente zur Untersuchung des dynamischen Systemverhaltens Sportler-Sportgerät-Umwelt. Dazu werden drei Fallbeispiele aus der Forschungstätigkeit der Arbeitsgruppe HLST an der Technischen Universität Chemnitz mit Methoden zur Verifikation von Simulationsmodellen – dem strukturierten Durchgehen, der Validierung im Dialog und dem Schreibtischtest – analysiert. Die Analyseergebnisse werden in eine Grobstruktur eingebettet, die aus relevanten Vorarbeiten zur Anwendung der Allgemeinen Modelltheorie abgeleitet ist. Die in den jeweiligen Fallbeispielen verwendeten Prozessschritte, Methoden und Werkzeuge werden dargestellt und die Entwicklungsergebnisse erörtert. Im Abschluss jedes Fallbeispiels wird der Entwicklungsprozess anhand von einheitlichen Kriterien bewertet. In einem abschließenden Schritt erfolgt die Zusammenführung der im Stand der Technik dargelegten Grundlagen und der in den drei Fallbeispielen gewonnenen Informationen zu einer strukturieren und kommentierten Methodik. / In this dissertation a methodology is conceived that aims to structure the development process of test arrangements that mechanically simulate the interaction of athlete, sports equipment and environment. Mechanical simulation in this context is defined as the physical replication of specific properties of the athlete (e.g. the shape of the human body, body weight, joint kinematics, inertia, external forces in specific movements) in order to conduct experiments to investigate the dynamic behavior of the system athlete-equipment-environment. Therefore, three case studies of mechanical simulation models that have been developed at Technische Universität Chemnitz are analyzed by applying the validation and verification methods “structured walkthrough”, “face validity” and “desk checking”. The results of that analysis are embedded into a framework that is derived by literature review on applied model theory. For each of the three development processes the procedure model is identified and main tools and methods are discussed. Every case study is finally assessed by using standardized evaluation criterions. Finally, the main findings of the analysis of the case studies as well as knowledge obtained by reviewing the state of the art in model theory and simulation methods are used to build up a structured and commentated guideline.