Full-depth, precast panel deck systems are becoming more common in bridge installation and repair. The objective of these systems is to achieve the performance of cast-in-place systems while simultaneously saving time and money. The structural behavior of these systems has been the subject of scrutiny in recent research. The Utah Department of Transportation demolished a steel I-girder bridge containing a precast panel deck system and provided two full-scale specimens for this project. Destructive testing was performed at Utah State University on the specimens to investigate three failure modes: flexural, beam shear, and punching shear. Finite-element models were created using ANSYS software to replicate experimental behavior. Overall, it was found that the elastic, post-elastic, and ultimate behavior of the full-scale bridge sections containing precast panel deck systems can be accurately predicted in analytical models. Another aspect of this project was to investigate changes in dynamic behavior as the system was subjected to flexural yield and failure. Point loads were applied and removed in increments, and dynamic testing was conducted at each load level. It was found that significant damage is somewhat noticeable by monitoring the changes in natural frequencies.

The presented master´s thesis deals with realization educational tasks on torsional vibration apparatus. It was designed and tested six educational experiments, to extend student´s knowledge of the static and dynamic properties of rotary systems. On the experimental apparatus it is possible to use inertial discs, adjustable semi-rotary damper with forced vibration crank drive unit. New set of shafts extends the variability of experimental apparatus. Students can realize the measurement of dynamic characteristics and torsional vibration using oscilloscope. New frame for the apparatus which meet all operation requirements was also designed. The solved problematics and all educational tasks are described in new prepared materials for teaching.

No description available.

No description available.

Magnetic bearings support turbomachinery by regulating their forces exerted in relation to the displacement of the machine supported. The regulating control system must be tuned for stable and safe operation of the rotor. The ultimate goal of this study is to determine the effects of changing controller gains on the behavior of the rotor during operation in its normal speed range with a known unbalance load. We also endeavor to confirm the model of the rotor supported the magnetic bearings, as an additional goal. We first investigate the modelling of rotors supported by magnetic bearings, including the model of the control system. We present a finite element model of a magnetic bearing supported rotor, and perform experiments to determine the characteristics of the control system which governs the magnetic forces on the rotor. The experimental control system characteristics confirm the expected characteristics from theory. With this knowledge, we perform simulations and experiments under the same forcing conditions to determine the accuracy of the model in predicting the experimental behavior of an unbalanced rotor. The model exhibits satisfactory ability in predicting the experimental behavior of the rotor under this loading. Our next step is to determine the effects of variation of proportional and integral controller gains on the behavior of the rotor. Both simulations and experiments show that an increase in the proportional controller gain results in an increase in the rotor’s first critical speed. An increase in the integral gain results in a small decrease in the location of the peak response speed in the speed range tested, while leaving the peak amplitude insignificantly changed. Again, simulations and experiments predict this result. We reach the following three conclusions from this study. First, the finite element model of the rotor/bearing system is a viable model for predicting the behavior of the experimental system. Second, tuning of the proportional gain shows a significant effect on the behavior of the rotor during unbalance loading across its speed range, due to considerable change in bearing stiffness caused by the tuning of this gain. Last, tuning of the integral gain has a small effect on the behavior of the rotor due to the change in bearing damping, too small to be considered significant. / Master of Science

Les propriétés que l’on souhaite exprimer sur les applications système d’information ne peuvent se restreindre aux propriétés statiques, dites propriétés d’invariance, qui portent sur des états du système pris au même moment. En effet, certaines propriétés, dites propriétés dynamiques, peuvent faire référence à l’état passé ou futur du système. Les travaux existants sur la vérification de telles propriétés utilisent généralement le model checking dont l’efficacité pour le domaine des systèmes d’information est plutôt réduite à cause de l’explosion combinatoire de l’espace des états. Aussi, les techniques, fondées sur la preuve, requièrent des connaissances assez avancées en termes de raisonnement mathématique et sont donc difficiles à mettre en œuvre d’autant plus que ces dernières ne sont pas outillées. Pour palier ces limites, nous proposons dans cette thèse des méthodes de vérification de propriétés dynamiques basées sur la preuve en utilisant la méthode formelle B. Nous nous intéressons principalement aux propriétés d’atteignabilité et de précédence pour lesquelles nous avons défini des méthodes de génération d’obligations de preuve permettant de les prouver. Une propriété d’atteignabilité permet d’exprimer qu’il existe au moins une exécution du système qui permet d’atteindre un état cible à partir d’un état initial donné. Par contre, la propriété de précédence permet de s’assurer qu’un état donné du système est toujours précédé par un autre état. Afin de rendre ces différentes approches opérationnelles, nous avons développé un outil support qui permet de décharger l’utilisateur de la tâche de génération d’obligations de preuve qui peut être longue et fastidieuse / The properties that we would like to express on data-intensive applications cannot be limited to static properties, called invariance properties, which depend on states taken at the same time. Indeed, some properties, called dynamic properties, may refer to the past or the future states of the system. Existing work on the verification of such properties typically use model checking whose effectiveness for data-intensive applications is rather limited due to the combinatorial explosion of the state space. In addition, the techniques, based on the proof, require fairly advanced knowledge and mathematical reasoning especially that they are not always supported by tools. To overcome these limitations, we propose in this thesis proof-based verification approaches that use the B formal method. We are mainly interested in reachability and precedence properties for which we defined formal rules to generate proof obligations that permit to discharge them. A reachability property expresses that there is at least one execution scenario that permits to reach a target state from a given initial state while a precedence property ensures that a given system state is always preceded by another state. To make these different approaches workable, we have developed a support tool that permits to discharge the users from tedious and error-prone tasks

In this thesis, a process is developed for designing elastomeric vibration isolators in order to provide vibration isolation for sensitive equipment being used in ROKETSAN A.S.&rsquo / s products. For this purpose, first of all, similar isolators are examined in the market. After that, appropriate elastomeric materials are selected and their temperature and frequency dependent dynamic properties are experimentally obtained. Parametric finite element model of the isolator is then constituted in ANSYS APDL using the properties of elastomeric materials and the conceptual design of the isolator. Then, according to design requirements, final design parameters of the vibration isolator are determined at the end of design iterations. In the next step, vibration isolator that was designed is manufactured using the elastomeric material chosen, by a local rubber company. Finally, design process is verified by comparing analysis and test results.

Term of remote-lab is certain types of laboratories which practical experiments are directedfrom a separate area by remote controller devices. This study is part of developing andupgrading advanced vibration remote laboratory. In the new remote lab, users have theability to measure the dynamic characteristics of the test object similar to the current existingremote lab. But in addition to current existing remote lab, they are capable to modifydynamic properties of the test object remotely by attaching vibration test instruments; such asa block of mass, spring-mass or non-linear spring. Doing several accurate experimental testsremotely on the test object are the toughest issues we faced as designers. In creating anddeveloping of this remote-lab, number of different approaches was adopted for producingwell-defined tests. Also, instead of implementing routine devices and techniques for regularvibration laboratories, the new prototypes were designed by finite elements method (FEM)and LABVIEW. For instance, the desirable test object, the attachment mechanism, usefulapplications, and proper software for managing via internet were prepared.

Made available in DSpace on 2015-05-14T13:21:35Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1948155 bytes, checksum: c82ffca61b521bccfe5b164df783aac2 (MD5) Previous issue date: 2014-05-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The study aimed to synthesize, store and monitor the biodiesel from the homogeneous alkaline transesterification of soybean and castor oil via methyl route, as well as evaluating the oxidative induction by the standard EN14112 and the PetroOxy basis over the period of 120 days. We observed the behavior of biodiesel blends inserted in the proportions of 20, 30, 40 and 50% v/v biodiesel from castor biodiesel from soybeans called M20 , M30 , M40 and M50 (in closed containers carbon steel). As physicochemical analyzes, specifications for both biodiesel and blends met the requirements of the limits allowed by the Technical Regulation No. 14/2012 of the National Agency of Petroleum, Natural Gas and Biofuels (ANP), except for the analysis of oxidative stability (M0 , M20 , M30 and M40) , the index of acidity after 60 days (M50) , after 90 days (M40 and M50) after 120 days (M100) and kinematic viscosity (M40 , M50 and M100) that had values outside the limits set by the standard. The fluid-dynamic properties showed similar behavior for methyl biodiesel blends and thus these concentrations of methyl biodiesel acts as a natural castor oil to methyl soybean biodiesel additive. The cetane number (CN) was higher for methyl soybean biodiesel. As the storage time increases the cetane number of towers. These values follow the trend of the Rancimat oxidative stability and PetroOxy methods. By the method EN 14112 has been found that the M50 blend is more resistant to oxidation during storage for 120 days on storage conditions. / O trabalho objetivou sintetizar, armazenar e monitorar os biodiesel proveniente da transesterificação homogênea alcalina do óleo de soja e mamona via rota metílica, bem como avaliar a indução oxidativa pela norma EN14112 e pelo método PetroOxy durante o período de 120 dias. Observou-se o comportamento dos biodiesel inseridos em blendas nas proporções de 20, 30, 40 e 50% v/v de biodiesel de mamona ao biodiesel de soja denominadas de M20, M30, M40 e M50 (em recipientes de aço-carbono fechado). Conforme análises físico-químicas, as especificações para ambos biodiesel e blendas satisfizeram as exigências dos limites permitidos pelo Regulamento Técnico nº 14/2012 da Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP), com exceção das análises de estabilidade oxidativa (M0, M20, M30 e M40), do índice de acidez após 60 dias (M50), após 90 dias (M40 e M50), após 120 dias (M100) e da viscosidade cinemática (M40, M50 e M100) que apresentaram valores fora dos limites estabelecido pela norma. As propriedades fluido-dinâmicas apresentaram comportamentos semelhantes para os biodiesel metílicos e blendas, assim, nestas concentrações o biodiesel metílico de mamona atua como um aditivo natural ao biodiesel metílico de soja. O Número de cetano (NC) apresentou-se maior para o biodiesel metílico de soja. A medida que o tempo de armazenamento aumenta o número de cetano eleva-se. Esses valores seguem a tendência de estabilidade oxidativa dos métodos Rancimat e PetroOxy. Através do método EN 14112 verificou-se que a blenda M50 é mais resistente ao processo de oxidação durante armazenamento de 120 dias sobre condições de estocagem.

Made available in DSpace on 2015-05-14T13:21:48Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1846340 bytes, checksum: 4509ef9787ae7fb094406e4231a153fa (MD5) Previous issue date: 2009-11-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The present paper aimed at synthesizing, storing and monitoring biodiesel from the alkaline homogeneous transesterification of soybean oil and castor oil, using the methanol route, as well as evaluating the oxidative stability, during a 60 day-period, by means of the EN14112 standard. Blends of castor oil biodiesel and soybean oil biodiesel, containing 10, 20 and 30% v/v of castor oil biodiesel, respectively called M10, M20 and M30, were stored within illuminated and closed glass containers and later characterized. The physico-chemical analyses, performed for the two different biodiesel types and their blends, met most the requirements stated by the Technical Rule number 7 from the Brazilian National Agency for Petroleum, Natural Gas and Biofuels. The exceptions were the oxidative induction time (0.60 h) and the kinematic viscosity (13.98 mm2/s), which displayed values outside the limits established by the aforementioned agency. The blends displayed a higher oxidative stability than the pure soybean oil biodiesel, obtained by the methanol route. Thus, the blends with higher amounts of castor oil biodiesel, obtained by the methanol route, presented a higher safety, on the storage standpoint. The fluid-dynamic properties, cloud point, pour point and cold filter plugging point, pointed out similar behaviors for the blends and the pure biodiesels, obtained by the methanol route. Thus, in the studied concentrations, the castor oil methanol biodiesel acts as a natural additive for the soybean methanol biodiesel. By means of the EN 14112 standard, it was observed that the blend M30 is the one that is the most immune to the oxidation process, during the storage period of 60 days. / O presente trabalho buscou sintetizar, armazenar e monitorar os biodiesel proveniente da transesterificação homogênea alcalina do óleo de soja e mamona via rota metílica, por catálise básica, bem como avaliar a estabilidade de indução oxidativa pela norma EN14112 durante o período de 60 dias. Também, foi observado o comportamento dos referidos biodiesel, inseridos em blendas nas proporções variando de 10, 20 e 30% v/v de biodiesel de mamona ao biodiesel de soja, denominadas de M10, M20 e M30 (em recipientes de vidro fechados com luz), respectivamente. Conforme análises físicoquímicas, todas as especificações para ambos biodiesel e blendas satisfizeram as exigências dos limites permitidos pelo Regulamento Técnico nº 7 da Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP). Com exceção do tempo de indução oxidativa (0,60 h) e a viscosidade cinemática (13,98 mm2/s) que apresentaram valores fora dos limites estabelecidos pela norma vigente. As blendas apresentaram maior estabilidade oxidativa em relação ao biodiesel metílico de soja, e, portanto, suas blendas mais concentradas em biodiesel metílico de mamona, apresentam maior segurança em relação ao armazenamento. O estudo das propriedades fluido-dinâmicas demonstrou que tanto os resultados de ponto de nevoa, fluidez e ponto de entupimento de filtro a frio, apresentaram comportamento semelhantes para os biodiesel metílicos e blendas e, portanto nestas concentrações o biodiesel metílico de mamona atua como um aditivo natural ao biodiesel metílico de soja. Através do método EN 14112 verificou-se que a blenda M30 é mais resistente ao processo de oxidação durante armazenamento de 60 dias.