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Объектом исследования является технологический процесс штамповки детали болт по ГОСТ 7798-70 на предприятии ООО «Арморика». Выполнено исследование влияния температуры нагрева заготовок на технологические факторы штамповки поковок фланца на пресс КГШП, а именно усилие штамповки, анализ напряженно – деформированного состояния штамповки поковки фланца, оценка проработки структуры металла. Выполнена разработка технологического процесса штамповки болта, расчет усилия пресса, компьютерное моделирование процесса горячей объемной штамповки болта с заданной в технологическом процессе температурой, технологичного, анализ влияния нагрева заготовок на технологические факторы, литературный обзор. / The object of the study is the technological process of stamping the bolt part according to GOST 7798-70 at the Armorica LLC enterprise. The study of the effect of the heating temperature of the workpieces on the technological factors of stamping flange forgings on the KGSHP press, namely the punching force, analysis of the stress–strain state of stamping flange forgings, evaluation of the study of the metal structure. The development of the technological process of bolt stamping, calculation of the press force, computer modeling of the process of hot volumetric stamping of a bolt with a temperature set in the technological process, technological, analysis of the effect of heating workpieces on technological factors, a literary review.

Die Präsentation stellt kurz die Grundlagen der Berechnung von Schraubenverbindungen in Anlehnung an die VDI-Richtlinie 2230 Teil 1 dar. Auch die vier FEM-Modellklassen, die die VDI 2230 Teil 2 (Entwurf) zur Berechnung von Mehrschraubenverbindungen vorschlägt, werden behandelt, und die in Creo Simulate vorhandenen Softwarefeatures zu deren Umsetzung vorgestellt. Es folgt eine Darstellung, was bei der Linearisierung von Schraubenverbindungen zur vereinfachten Berechnung zu beachten ist, und wieso bei der Berechnung im FEM-System dann nicht notwendigerweise eine Vorspannung benötigt wird. Ausführlich wird das neue Schraubenfeature in Creo Simulate betrachtet, das eine weitgehend automatisierte Modellierung und Berechnung von Standardverschraubungen erlaubt. Weitere Features, wie die neuen Vorspannelemente, werden erläutert, sowie auch die Grenzen der Software aufgezeigt. Abschließend werden zwei anspruchsvolle Anwendungsbeispiele vorgestellt: Eine zentrisch belastete Verschraubung mit Berücksichtigung von Elasto-Plastizität und einer komplexen Lasthistorie (Anziehen durch Anzugsmoment, Setzeffekte, Entfall des Torsionsmomentes durch das Anziehen, Betriebskraft) sowie eine exzentrisch belastete Verschraubung, die wegen eines relativ dünnen Flansches starke Biegezusatzbeanspruchungen erfährt. / The presentation shows the foundations of bolt analysis according to VDI-guideline 2230 part 1. In addition, the four FEM model classes proposed in VDI 2230 part 2 (draft) are described, as well as the features available in Creo Simulate to realize these model classes. Next, the presentation shows the requirements for linearizing bolted connections, and why in a FEM analysis with a linearized connection no preload is necessary. The new fastener feature introduced in Creo Simulate is explained in detail. This feature allows the automated modeling and analysis of bolted connections having standard geometry. Further software features, like pretension elements, as well as the current software limitations are shown. Finally, two advanced application examples are shown: A centrically loaded bolted connection taking into account elasto-plasticity and a complex load history (tightening torque, embedding, removal of tightening stress, operational load), and an eccentrically loaded flange connection, which is subjected to high additional bending loads because the flange is relatively thin.

Le boulonnage et le câblage à ancrage réparti sont deux techniques de renforcement du terrain couramment utilisées dans l'industrie minière et dans le génie civil. Au fil de cette recherche, on s'intéresse à la réponse de ces éléments sous des sollicitations axiales de traction, en régime statique. Dans ces conditions, l'expérience montre que la rupture se produit le plus fréquemment à l'interface barre-scellement via un processus de décohésion qui commence dès que la force sur la barre atteint une valeur limite. L'objectif est de mieux comprendre le comportement de cette interface, avant et après rupture. Premièrement, on revoit l'état de l'art afin de comprendre le travail effectué et les aspects non maîtrisés à ce jour. Deuxièmement, on décrit des outils analytiques qui permettent de comprendre la réponse d'un boulon ou d'un câble à ancrage réparti soumis à une force de traction. Ensuite, on présente les études expérimentales menées en laboratoire et in situ. Des essais d'arrachement ont été effectués pour déterminer les principaux facteurs qui régissent la réponse de l'interface. Finalement, on analyse les résultats des essais effectués en laboratoire sur les boulons. Après l'obtention des variables nécessaires, on propose un modèle semi-empirique d'interface, qui devra être validé par des essais complémentaires. Cette perspective et d'autres améliorations sont également présentées. / Rockbolting and cablebolting are two ground reinforcement techniques broadly used in civil and mining engineering. This research focuses on the behaviour of fully grouted bolts subjected to tensile axial loads, in static conditions. Under these circumstances, experience throughout the world proves that failure usually takes place at the bolt-grout interface via a decoupling process that starts if the load on the bolt exceeds a critical value. The objective is to gain more insight into the behaviour of this interface, before and after failure. First, the state-of-the-art is presented to understand the existing advances and to identify the lacking aspects. Secondly, analytical tools that help understand the response of a fully grouted bolt subjected to a tensile load are described. Then, the field and laboratory experimental campaigns are exposed. Pull-out tests have been conducted to determine the most influencing parameters on the interface behaviour. Finally, the laboratory results on rockbolts are analyzed. Once the necessary variables are obtained, a semi-empirical interface behaviour model is proposed. The further evaluation of this model and other improvements are suggested as perspectives of evolution.

No mercado mundial existe uma visível tendência de tornar as obras mais industrializadas e racionalizadas com o objetivo de reduzir os desperdícios, acelerar a velocidade de execução das obras e garantir maior qualidade às mesmas. A adoção de elementos estruturais com certo grau de industrialização pode trazer benefícios em relação aos custos, à mão de obra, ao tempo de execução e ao impacto ambiental. Neste contexto, as estruturas mistas de aço e concreto satisfazem essa necessidade, pois tanto os elementos de aço quanto os elementos de concreto podem ser pré-fabricados, ficando apenas as etapas de içamento e montagem a serem realizadas na obra, reduzindo o uso de fôrmas e escoramentos. Os pisos mistos de aço e concreto de pequena altura caracterizam-se pelo embutimento da laje de concreto na altura do perfil de aço, sendo a principal vantagem, em relação ao piso misto convencional, a redução da altura total do composto. Portanto, este trabalho tem como objetivo analisar o comportamento de pisos mistos de aço e concreto de pequena altura com laje alveolar em concreto protendido por meio de ensaios de cisalhamento direto (push-out test) e de flexão. Na solução proposta, a transferência de esforços entre o perfil de aço e a laje alveolar foi feita por meio de conectores tipo pino com cabeça e concreto moldado no local. Os resultados demonstraram-se promissores em termos de comportamento do piso misto de pequena altura, aumentando significativamente a rigidez do sistema em relação à viga de aço isolada. Em complemento, foi desenvolvida uma simulação numérica dos modelos físicos ensaiados utilizando o pacote computacional DIANA®, fundamentado no método dos elementos finitos, na qual o modelo numérico representou adequadamente o comportamento dos pisos mistos de pequena altura, permitindo análises paramétricas. / On the world market, there is a visible tendency to turn buildings construction more industrialized and rationalized in order to reduce waste, accelerate the construction speed and ensure higher quality to them. The adoption of structural elements with a degree of industrialization can bring benefits regarding costs, labor, construction time and environmental impact. In this context, steel and concrete composite structures satisfy this need, since steel and concrete elements can be prefabricated, with only lifting and mounting steps to be performed on site, reducing use of formwork and shoring. A type of slim floor system consists in precast concrete hollow core slabs supported on the lower flange of steel beams. The major advantage of this solution, compared to conventional composite beam, is reducing the overall height of the floor. Therefore, this study aims to analyze the behavior of slim floor with prestressed concrete hollow core slabs through push-out and bending tests. In the proposed solution, the transfer of forces between steel beam and hollow core slabs was made by stud bolts and cast on site concrete. The obtained results proved to be promising in terms of slim floor behavior, significantly increasing the system stiffness regarding the isolated steel beam. In addition, a numerical modeling of the studied slim floor system was developed, using finite element based software DIANA®, in which the numerical model adequately represented the behavior of the composite beam, allowing parametric analysis.

The I-35W Bridge over the Mississippi River in Minneapolis, MN had a catastrophic failure in the main span of the deck truss in 2007. This collapse has brought significant attention on the gusset plate connections in steel truss bridges throughout the U.S. Steel truss bridge gusset plate design has not received much focus in the past 40 years, and there is a lack of consensus within the design profession on the procedures to evaluate, design, and rate these critical elements. In the short term, based on the best available information on the gusset plate design, the Federal Highway Administration (FHWA) has issued preliminary guidance. Although some experimental research has been conducted on the ultimate strength of gusset plates, much of this work has been directed toward the performance of tension members and their connections. There has been limited experimental work on the compression capacity and stability of gusset plates, but most of this work is relevant primarily to bracing connections common in building structures. This research focuses on comprehensive experimental and analytical studies on steel truss bridge gusset plate behavior. The studies include comparisons of advanced analytical models with the responses from large-scale experimental tests using discrete and innovative full-field measurements. The calibrated finite element analysis models are then utilized to study a variety of gusset plate configurations. Improved mechanistic idealizations that better capture the observed behavior in the experiments and analytical studies are proposed as the result of this work. The design checks recommended in this thesis present a comprehensive methodology for determining the ultimate gusset plate resistance. This research provides a large database of original results that will be useful for future similar studies. In addition, this research provides modeling procedures that permit the study of steel truss bridge connections and their adjacent framing members using truss bridge sub-assemblies. Based on the comprehensive analytical studies, simple and accurate design calculation procedures to assess the nominal ultimate strength of steel truss gusset plate connections are recommended for steel truss bridge gusset plate connections.

This submission comes in two parts; the written dissertation, Contemporary art: the key issues, and the exhibition Melbourne - Moderne. When taken together they present a discourse on the conditions facing contemporary art practice and one artist’s response to these conditions in the context of Melbourne 2003-2007. (For complete abstract open document)

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-10-16T17:40:13Z No. of bitstreams: 1 GILSON ACIOLE RODRIGUES – DISSERTAÇÃO (PPGFísica) 2016.pdf: 1524954 bytes, checksum: 9054f2fa535b67f3184b1f692caa7c88 (MD5) / Made available in DSpace on 2018-10-16T17:40:13Z (GMT). No. of bitstreams: 1 GILSON ACIOLE RODRIGUES – DISSERTAÇÃO (PPGFísica) 2016.pdf: 1524954 bytes, checksum: 9054f2fa535b67f3184b1f692caa7c88 (MD5) Previous issue date: 2016-09-28 / Capes / A influência dos deslocamentos parafuso em sistemas quânticos tem recebido considerável atenção nos últimos anos. Alguns trabalhos são baseados na teoria geométrica de defeitos em semicondutores e desenvolvidos por Katanaev Volovich. Nesta abordagem, o semicondutor com um deslocamento parafuso é descrito por uma variedade de Riemann-Cartan onde o deslocamento parafuso está associado ao vetor Burgers. Neste limite do contínuo, um deslocamento parafuso afeta um sistema quântico como um tubo de fluxo magnético isolado, causando fenômenos de interferência tipo Aharonov-Bohm (AB). O espectro de energia de elétrons em torno deste tipo de defeito mostra uma configuração semelhante a do sistema AB. Neste trabalho, investigamos a influência de um deslocamento parafuso sobre os níveis de energia e as funções de onda de um elétron confinado em um potencial pseudo-harmônico bidimensional (2D) sob a influência de um campo magnético externo para o ponto quântico e campo Aharonov-Bohm para um pseudo-ponto quântico. As soluções exatas para autovalores de energia e funções de onda são computadas em função do campo magnético uniforme, fluxo Aharonov-Bohm, número quântico magnético e do parâmetro que caracteriza o deslocamento parafuso, o vetor Burgers. Foram investigadas as modificações devido à deslocação parafuso no coeficiente de absorção de luz e na frequência de absorção limiar. Descobrimos que conforme o vetor Burgers aumenta, as curvas de frequência são impusionadas para cima em direção ao crescimento do mesmo. Um aspecto interessante que observamos é que o fluxo Aharonov-Bohm pode ser ajustado de forma a cancelar o efeito do deslocamento parafuso. / The influence of screw dislocations in quantum systems has received considerable attention in recent years. Some works are based on the geometric theory of defects in semiconductors and developed by Katanaev Volovich. In this approach the semiconductor with a screw dislocation is described by a variety of Riemann-Cartan where the screw dislocation is associated with the Burgers vector. This limit of the continuum, a screw displacement affects a quantum system as an isolated magnetic flux tube, causing phenomena of interference type Aharonov-Bohm (AB). The electron energy spectrum around this type of defect shows a configuration similar to the AB system. In this work, we investigated the influence of a screw dislocation on the energy levels and the wavefunctions of an electron confined in a two-dimensional pseudoharmonic quantum dot under the influence of an external magnetic field inside a dot and Aharonov-Bohm field inside a pseudodot. The exact solutions for energy eigenvalues and wavefunctions are computed as functions of applied uniform magnetic field strength, Aharonov-Bohm flux, magnetic quantum number and the parameter characterizing the screw dislocation, the Burgers vector. We investigate the modifications due to the screw dislocation on the light interband absorption coefficient and absorption threshold frequency. We found that as the Burgers vector increases, the curves of frequency are pushed up towards of the growth of it. One interesting aspect which we have observed is that the Aharonov-Bohm flux can be tuned in order to cancel the screw effect of the model.

No mercado mundial existe uma visível tendência de tornar as obras mais industrializadas e racionalizadas com o objetivo de reduzir os desperdícios, acelerar a velocidade de execução das obras e garantir maior qualidade às mesmas. A adoção de elementos estruturais com certo grau de industrialização pode trazer benefícios em relação aos custos, à mão de obra, ao tempo de execução e ao impacto ambiental. Neste contexto, as estruturas mistas de aço e concreto satisfazem essa necessidade, pois tanto os elementos de aço quanto os elementos de concreto podem ser pré-fabricados, ficando apenas as etapas de içamento e montagem a serem realizadas na obra, reduzindo o uso de fôrmas e escoramentos. Os pisos mistos de aço e concreto de pequena altura caracterizam-se pelo embutimento da laje de concreto na altura do perfil de aço, sendo a principal vantagem, em relação ao piso misto convencional, a redução da altura total do composto. Portanto, este trabalho tem como objetivo analisar o comportamento de pisos mistos de aço e concreto de pequena altura com laje alveolar em concreto protendido por meio de ensaios de cisalhamento direto (push-out test) e de flexão. Na solução proposta, a transferência de esforços entre o perfil de aço e a laje alveolar foi feita por meio de conectores tipo pino com cabeça e concreto moldado no local. Os resultados demonstraram-se promissores em termos de comportamento do piso misto de pequena altura, aumentando significativamente a rigidez do sistema em relação à viga de aço isolada. Em complemento, foi desenvolvida uma simulação numérica dos modelos físicos ensaiados utilizando o pacote computacional DIANA®, fundamentado no método dos elementos finitos, na qual o modelo numérico representou adequadamente o comportamento dos pisos mistos de pequena altura, permitindo análises paramétricas. / On the world market, there is a visible tendency to turn buildings construction more industrialized and rationalized in order to reduce waste, accelerate the construction speed and ensure higher quality to them. The adoption of structural elements with a degree of industrialization can bring benefits regarding costs, labor, construction time and environmental impact. In this context, steel and concrete composite structures satisfy this need, since steel and concrete elements can be prefabricated, with only lifting and mounting steps to be performed on site, reducing use of formwork and shoring. A type of slim floor system consists in precast concrete hollow core slabs supported on the lower flange of steel beams. The major advantage of this solution, compared to conventional composite beam, is reducing the overall height of the floor. Therefore, this study aims to analyze the behavior of slim floor with prestressed concrete hollow core slabs through push-out and bending tests. In the proposed solution, the transfer of forces between steel beam and hollow core slabs was made by stud bolts and cast on site concrete. The obtained results proved to be promising in terms of slim floor behavior, significantly increasing the system stiffness regarding the isolated steel beam. In addition, a numerical modeling of the studied slim floor system was developed, using finite element based software DIANA®, in which the numerical model adequately represented the behavior of the composite beam, allowing parametric analysis.