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Desenvolvimento de técnica de medição e obtenção de dados experimentais envolvidos no ciclo de trabalho dos compressores herméticos alternativos / Development of techniques to measure and extract experimental data of hermetic compressor work cycleMarcelo Alexandre Real 20 December 2005 (has links)
Essa dissertação desenvolve e faz uso de uma técnica de medição com objetivo de obter dados experimentais envolvidos no ciclo de trabalho dos compressores herméticos alternativos, largamente utilizados nos sistemas de refrigeração. O trabalho mostra o comportamento das válvulas de admissão e descarga durante o funcionamento do compressor, as pressões no cilindro, na sucção, na descarga e também a variação de rotação do eixo durante um ciclo de compressão completo. Todas as características mensuradas estão referenciadas à posição angular do eixo do compressor, o que permitiu monitorar todos os eventos em função do seu deslocamento angular. Para o desenvolvimento desse trabalho foi necessário planejar um sistema de medição robusto, não vulnerável aos fatores ambientais, presentes dentro da carcaça do compressor. A limitação do espaço físico foi um fator de grande importância na escolha dos sensores, assim como a velocidade de resposta dos instrumentos, pois um ciclo de compressão tem período menor que 0,020 segundos. A coleta dos dados e a análise dos sinais foram realizadas com o auxilio de hardware apropriado e software especialmente desenvolvido. / In this dissertation it is developed and applied measurement methods to obtain experimental data of a hermetic compressor work cycle, widely used in the refrigeration systems. This work shows the suction and discharge valve behaviors, the pressure in the cylinder, as well as in the discharge and suction chambers, and also crankshaft rotation variation during a complete compression cycle. All the measurements are reference to crankshaft angular position of compressor which allows to verify the events as a function of the crankshaft angular displacement. For the development of this work it was necessary to plan a reliability measure system, not affected by environmental factors inside the housing of compressor. The inner space limitation was an important feature for choosing the sensors as well as their time response, since the period compression cycle is less than 0.020 seconds. The data acquisition and signal analysis were done with appropriate hardware and it was developed a specific software.
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Desenvolvimento econômico e deslocamento populacional no primeiro governo Vargas (1930-1945) / Economic development and displacement population in the first government of Vargas (1930-1945)Julio Cesar Zorzenon Costa 23 January 2008 (has links)
Esta tese discute a integração do mercado nacional, ocorrida no primeiro Governo Vargas (1930-1945), como importante fator para a construção de uma estrutura econômica de base industrial, que permitiu a entrada da economia brasileira em uma fase de grande desenvolvimento e crescimento econômicos. Enfoca, nesse processo, a função exercida pelos deslocamentos populacionais. A integração do mercado nacional reclamava a construção de um novo padrão de deslocamentos populacionais no país. Embora as características dos deslocamentos populacionais já estivessem se modificando, o Estado interveio nesse processo, mediante a elaboração de políticas específicas, visando aprofundar e acelerar a integração do mercado, inclusive a do mercado de trabalho. As políticas relativas aos deslocamentos populacionais, praticadas e elaboradas no primeiro Governo Vargas, evidenciam a intencionalidade desse governo em apoiar e impulsionar o desenvolvimento de um novo padrão de acumulação urbano-industrial. Mesmo que não tenham alcançado a concretização dos objetivos propostos, as políticas relativas aos deslocamentos populacionais, iniciadas no primeiro Governo Vargas, permitiram a constituição de bases sobre as quais se daria, embora com características relativamente diferentes, o significativo desenvolvimento econômico alcançado no pós-guerra. / This thesis argue the national market integration, that happened in the first government of Vargas (1930-1945), with great factor to the construction of economic structure of industrial base, that allowed the Brazilian economic into a time of great development and economic growth. In this process, the focus is on the work of the population displacement. The national market integration claimed the construction of a new standard of population displacement in the country. Despite of the characteristics of the populations displacement was already in modification, the State mediate on this process, because of the creation of specific polices, trying to go deep and accelerate the market integration, including the work market. The relative politics to the population displacement, practiced and created during the first government of Vargas, shows the intention of this government to support and impulse the development of a new standard of urban industrial accumulation. Even If they didnt achieve their objectives that were proposed, the politics related to the population displacement that started in the first government of Vargas, allowed the constitution of the bases that was going to be used, in spite of the characteristics relatively different, the significative economic development realized after the war.
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Avaliação da correlação entre os deslocamentos de disco e alterações ósseas degenerativas da articulação temporomandibular por meio de imagens de ressonância magnéticaDias, Isabela Maddalena 28 March 2011 (has links)
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Previous issue date: 2011-03-28 / O presente estudo teve como objetivo avaliar por meio de imagens de ressonância magnética a prevalência e os tipos de deslocamentos de disco e alterações ósseas degenerativas que podem acometer a articulação temporomandibular (ATM) de indivíduos adultos portadores de sinais e sintomas de desordens temporomandibulares (DTM), verificando a correlação entre estes achados. Foram avaliadas 224 articulações de112 pacientes, de ambos os gêneros, com indicação para o exame de ressonância magnética. A possibilidade de visualizar simultaneamente o disco articular e estruturas de tecido duro da ATM por meio de um único exame permitiu verificar estas condições e a correlação entre
ambas. Para isso um examinador calibrado avaliou as imagens atribuindo escores em relação ao deslocamento do disco articular e alterações ósseas degenerativas. O deslocamento do disco articular foi verificado em 58,42% das ATM avaliadas no corte sagital. O deslocamento anterior de disco com redução foi o mais frequente, ocorrendo em 67,18% dos casos de articulações com deslocamento do disco. Nos
cortes coronais, o deslocamento do disco articular foi verificado em 56,65% das ATM avaliadas, sendo o deslocamento medial visto em 96% dos casos. Com relação às alterações ósseas degenerativas as mesmas foram verificadas em 53,94% das ATM analisadas. Houve correlação significativa entre o deslocamento de disco com redução e o aplainamento condilar; deslocamento de disco sem redução e o
aplainamento condilar; deslocamento de disco sem redução e alterações degenerativas associadas (aplainamento e erosão; aplainamento, osteófito e erosão; aplainamento e osteófito; erosão e esclerose, aplainamento e esclerose; aplainamento, osteófito e esclerose) e deslocamento lateral do disco articular e
osteófitos. A associação entre casos avançados de deslocamento de disco e a ocorrência de alterações degenerativas, enfatizam a importância das imagens por ressonância magnética tanto para um diagnóstico preciso e elaboração de um correto plano de tratamento, quanto para fins prognósticos, nos casos que o exame clínico não é suficiente para estes objetivos. / The aim of this study is evaluate by means of magnetic resonance images the prevalence and types of disc displacements and degenerative bone changes that can affect the temporomandibular joint (TMJ) of patients with signs and symptoms of temporomandibular disorders (TMD),checking the correlation between these findings. Two hundred twenty-for temporomandibular joints of 112 patients of both genders,
with an indication for MRI, were evaluated The possibility to simultaneously view the disc and hard tissue structures of the TMJ by a single examination has shown these conditions and the correlation between them. For this purpose a calibrated examiner evaluated the images by assigning scores in relation to the disc displacement and degenerative bone changes. The disc displacement was found in 58.42% of TMJ
evaluated on sagittal sections. The anterior displacement of the disc with reduction was the most common, occurring in 67.18% of cases of joints with disc displacement. In coronal sections, disc displacement was observed in 56.65% of TMJ evaluated, and the medial displacement seen in 96% of cases. With respect to degenerative bone changes, the same were observed in 53.94% of TMJ analyzed. There was significant correlation between disc displacement with reduction and condylar flattening, disc displacement without reduction and condylar flattening, disc displacement without reduction and degenerative changes associated (flattening and erosion, flattening, osteophyte and erosion; flattening and osteophytes, erosion and sclerosis, flattening and sclerosis, flattening, osteophytes and sclerosis) and lateral displacement of the disc and osteophytes. The association between advanced cases
of disc displacement and the occurrence of degenerative changes, emphasize the importance of magnetic resonance imaging to an accurate diagnosis and development of an appropriate treatment plan, and for prognosis in cases than clinical examination is not sufficient for these purposes.
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Unidades de Policia Pacificadora e aspectos espaciais do crime no Estado Rio de JaneiroFernandes, Jessica de Oliveira 11 June 2018 (has links)
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Previous issue date: 2018-06-11 / A avaliação das Unidades de Polícia Pacificadora (UPPs) no crime do Rio de Janeiro é um tema já discutido na literatura, no entanto, os autores tratam do tema não levam em consideração os deslocamentos espaciais de crime potencialmente existentes. Até o ano de 2014, as UPPs haviam sido implementadas em 38 comunidades circunscritas em 26 distritos policiais (DPs). Este trabalho tem o objetivo de avaliar o impacto das UPPs nas taxas de criminalidade entre 2007 e 2016. Para isso, foi realizada uma avaliação de tratamento por meio da abordagem das diferenças-em-diferenças espacial (SDID), método capaz de modelar o deslocamento espacial do crime das regiões tratadas para regiões vizinhas. Os resultados revelam que as UPPs reduziram as taxas de homicídios dolosos, furto a veículos e roubo de veículos nas regiões ocupadas. Além disso, houve um transbordamento dos benefícios da política pública para as regiões vizinhas. / The impact evaluation of Unidades de Polícia Pacificadora (UPPs) in the Rio de Janeiro crime is a topic already discussed in the literature, however, the authors do not take into account the potentially existing spatial displacements of crime. Until the year of 2014, the UPPs have been implemented in 38 communities circumscribed in 26 police districts (DPs). This study is aimed at measuring the impact of the UPPs on crime rates between 2007 and 2016. To do so, a impact evaluation was performed by approaching the spatial difference-in-differences (SDID) which is able to treat crime spatial displacement of regions treated to neighboring regions. The findings reveal that the UPPs have reduced homicide rates, vehicle thefts and vehicles obberies at the occupied regions. Besides, there was a spatial spillover of the benefits of UPPs to the neighboring regions.
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Narrativas migrantes: deslocamentos em Azul-corvo, de Adriana Lisboa e Terra estrangeira, de Walter SallesBarreto, Luiza Puntar Muniz 06 June 2017 (has links)
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1. DISSERTAÇÃO LUIZA Versão final.pdf: 1064454 bytes, checksum: 2347543c843eefda0b64ef5bbef3e4d3 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Por meio de uma abordagem comparativa, a presente dissertação discute o tema da migração
no romance Azul-corvo (2010), de Adriana Lisboa e no longa-metragem Terra estrangeira
(1996), de Walter Salles. Correspondendo às mudanças culturais, sociais e geopolíticas
projetadas na pós-modernidade, essas obras tematizam os deslocamentos pelos espaços
contemporâneos, apresentando personagens em trânsito que evidenciam crises existenciais,
identitárias e afetivas. Assim, essas narrativas de deslocamento colocam em voga as
concepções de identidades subjetivas e coletivas, reinscrevendo o tema do nacional,
engendrando problematizações a respeito das experiências de exílio e, ao mesmo tempo,
inscrevendo o olhar plural e dialógico que caracteriza as novas concepções identitárias em
formação. É sob tais perspectivas que procuramos elucidar e analisar as figurações dos
sujeitos migrantes que protagonizam tais narrativas, levando em consideração tanto a
elaboração dos espaços de migração, como de seus lugares de origem e discutindo a
incidência ou não de possibilidades de reterritorialização, a se desenhar de acordo com o
contexto social e político específico de cada uma das obras / Through a comparative approach, this dissertation address the theme of migration in Adriana
Lisboa's novel Azul-corvo (2010) and Walter Salles' feature film Terra estrangeira (1996).
Corresponding to the cultural, social and geopolitical changes projected in postmodernity,
these works discuss the displacement in contemporary spaces, presenting characters in transit
that show existential, identity and affective crises. Therefore, these narratives of displacement
put in vogue the conceptions of subjective and collective identities, reinscribing the theme of
the national, engendering problematizations about the experiences of exile and, at the same
time, inscribing the plural and dialogical look that characterizes the new identity conceptions
in formation. According to such perspectives, we seek to elucidate and analyze the figurations
of the migrant subjects that are staring in the narratives, considering both the elaboration of
the migration spaces and their places of origin and discussing the incidence or not of
possibilities of reterritorialization, to be drawn according to the specific social and political
context of each of the works
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PROPERTIES AND OPTIMIZATION OF RESPIRATORY NAVIGATOR GATING FOR SPIRAL CINE DENSE CARDIAC MRIHamlet, Sean Michael 01 January 2017 (has links)
Cardiac magnetic resonance (MR) imaging can non-invasively assess heart function. Displacement encoding with stimulated echoes (DENSE) is an advanced cardiac MR imaging technique that measures tissue displacement and can be used to quantify cardiac mechanics (e.g. strain and torsion). When combined with clinical risk factors, cardiac mechanics have been shown to be better predictors of mortality than traditional measures of heart function.
End-expiratory breath-holds are typically used to minimize respiratory motion artifacts. Unfortunately, requiring subjects to breath-hold introduces limitations with the duration of image acquisition and quality of data acquired, especially in patients with limited ability to hold their breath. Thus, DENSE acquisitions often require respiratory navigator gating, which works by measuring the diaphragm during normal breathing and only acquiring data when the diaphragm is within a pre-defined acceptance window.
Unfortunately, navigator gating results in long scan durations due to inconsistent breathing patterns. Also, the navigator echo can be used in different ways to accept or reject image data, which creates several navigator configuration options. Each respiratory navigator configuration has distinct advantages and disadvantages that directly affect scan duration and image quality, which can affect derived cardiac mechanics. Scan duration and image quality need to be optimized to improve the clinical utility of DENSE. Thus, the goal of this project was to optimize those parameters. To accomplish this goal, we set out to complete 3 aims: 1) understand how respiratory gating affects the reproducibility of measures of cardiac mechanics, 2) determine the optimal respiratory navigator configuration, and 3) reduce scan duration by developing and using an interactive videogame to optimize navigator efficiency.
Aim 1 of this project demonstrated that the variability in torsion, but not strain, could be significantly reduced through the use of a respiratory navigator compared to traditional breath-holds. Aim 2 demonstrated that, among the configuration options, the dual-navigator configuration resulted in the best image quality compared to the reference standard (traditional breath-holds), but also resulted in the longest scan duration. In Aim 3, we developed an interactive breathing-controlled videogame and demonstrated that its use during cardiac MR can significantly reduce scan duration compared to traditional free-breathing and also led to a small improvement in signal-to-noise ratio of the acquired images.
In summary, respiratory navigator gating with DENSE 1) reduces the variability in measured LV torsion, 2) results in the best image quality with the dual-navigator configuration, and 3) results in significantly shorter scan durations through the use of an interactive videogame. Selecting the optimal navigator configuration and using an interactive videogame can improve the clinical utility of DENSE.
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[en] NETWORK SIMULATOR FOR TWO-PHASE DISPLACEMENT IN CONSTRICTED CAPILLARY CHANNELS / [pt] SIMULADOR DE REDE PARA ESCOAMENTO BIFÁSICO EM CAPILARES COM CONSTRIÇÃOMARTHA SALLES FRANCA 24 January 2018 (has links)
[pt] A compreensão dos mecanismos e fenômenos de transporte relacionados
ao fluxo multifásico em meios porosos é de grande relevância para
diversas aplicações práticas como captura e sequestro de dióxido de carbono,
transporte em células de combustível e recuperação avançada de reservatórios
de hidrocarbonetos. A geometria do espaço poroso e as interações
dos fluidos com sua parte sólida determinam propriedades macroscópicas
como porosidade, permeabilidades relativas e pressão capilar. Porém, a visão
em escala microscópica fornece uma melhor descrição e entendimento dos
processos físicos e químicos do escoamento de fluidos no espaço poroso. Neste
trabalho desenvolvemos um simulador de rede de poros para análise do escoamento
bifásico de fluidos imiscíveis tanto para o processo de drenagem
quanto para o de embebição. O modelo de rede 240×40 tem capilares com
raios médios na ordem de 52.35 micrometro com constrição. Os padrões de escoamento
e eficiências de deslocamento foram obtidos para diferentes razões
de viscosidade e números de capilaridade. Os resultados encontrados, considerando
deslocamento pistão, foram similares a de experimentos realizados
previamente, injetando água no meio saturado de óleo. Na drenagem,
a saturação residual de óleo cai com o aumento do número de capilaridade.
O padrão de escoamento observado é de fingerings viscosos e, a frente de
deslocamento torna-se mais estável com o aumento da razão de viscosidade.
Na embebição, para números de capilaridade mais baixos, o escoamento foi
dominado por fingers capilares. Para números de capilaridade altos, fingers
viscosos foram predominantes e, com o aumento da razão de viscosidade, a
frente apresentou maior estabilidade. / [en] Understanding the mechanisms and transport phenomena of multiphase
flow in porous media has great relevance in several practical applications,
such as capture and sequestration of carbon dioxide, transport in fuel
cells and enhancement hydrocarbon recovery. The geometry of pore space
and the fluid interactions with the solid determine macroscopic properties
such as porosity, relative permeabilities and capillary pressure. However,
microscopic analysis provides a better description and comprehension of
physical and chemical processes of fluid flow in the pore space. In this work,
we developed a pore-network simulator to analyze immiscible two-phase flow
for both drainage and imbibition processes. The 240×40 pore-network model
has constricted capillary channels with radius on the order of 52.35 micrometer. Flow
patterns and displacement efficiencies evaluation were obtained at different
viscosity ratios and capillary numbers. The results, considering piston-like
displacement, were similar to experiments realized previously, injecting water
in an oil saturated medium. In the drainage process, the oil saturation
reduces with increasing capillary number. The observed flow pattern is viscous
fingerings and the front is stable with the higher viscosity ratio. In
imbibition, the flow was dominated by capillary fingers at low capillary
numbers. At high capillary numbers, viscous fingers were predominant and,
with increasing viscosity ratio, the front presented higher stability.
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Análisis y diseño estructural comparativo con la norma sismo resistente E.030-2014 vs. E.030-2003 de un edificio multifamiliar de 5 pisos en Distrito de SurquilloQuispe Ledesma, Fredy January 2015 (has links)
El presente trabajo tiene por objetivo Realizar el diseño estructural con el proyecto de norma de diseño sismo resistente E.030-2014 y compararla con la a la E.030-2003 para comprobar sus ventajas e incidencia en el diseño de
un edificio de cinco pisos destinados a multifamiliar, esta comparación se realizará durante el análisis sísmico del edificio, aplicando y comparando los parámetros de cada una de estas norma simultáneamente, para de esa manera comparar los resultados de las solicitaciones que producen a la hora de realizar el diseño estructural , también verificar en que porcentaje varían estas dos demandas y si este influye económicamente en la concepción de los planos estructurales del proyecto así como la influencias de los nuevos parámetros en el comportamiento sísmico del edificio en conjunto.
La metodología a utilizar para el desarrollo de esta tesis es del tipo cuantitativo nivel descriptivo y de método diseño experimental y explicativo, longitudinal y prospectivo. .
El proyecto que se utilizara para la comparación y el diseño estructural, se ubica en la ciudad de Lima en el distrito de Surquillo, sobre un terreno de 503.63m2 de área. El suelo está constituido de la grava típica de la ciudad de Lima, con un esfuerzo admisible (Capacidad Portante) del terreno de 4Kg. /cm2 a 1.30 m. de profundidad.
Después haber realizar toda las etapas de diseño y enfocándonos en el análisis sísmico comparativo con las dos versiones de la norma E.030 obtenemos resultados muy próximos la diferencia de demanda sísmica está en el orden del 1%-6% y por eso a la hora de diseñar con los resultados de cualquiera de las dos versiones de la norma E.030, no causa problema desde el punto de vista económico. También se observa que hay parámetro que limitan la irregularidad en el edificio y mejoran el comportamiento sísmico de este.
Se finaliza con la elaboración de los planos estructurales de todo el edificio que es uno de los objetivos fundamentales de esta investigación.
This paper aims to Perform structural design with the draft of E.030-2014 earthquake resistant design and compare it with the E.030-2003 to check their benefits and impact on design
a five-story building intended for multifamily, this comparison will take place during the seismic analysis of the building, using and comparing the parameters of each of these standards simultaneously, to thereby compare the results of the stresses that occur when making structural design, also check that these two percentage varying demands and economically if it influences the design of structural drawings of the project as well as the influences of the new parameters on the seismic behavior of the building as a whole.
The methodology used to develop this thesis is the quantitative level and descriptive and explanatory experimental, longitudinal and prospective design method. .
The project to be used for comparison and structural design, is located in the city of Lima in the district of Surquillo, on a land of 503.63m2 area. The floor is made of the typical gravel Lima, with allowable stress (bearing capacity) 4 kg terrain. / Cm2 to 1.30 m. deep.
After having performed all stages of design and focusing on the comparative seismic analysis with two versions of the E.030 standard we get very close results the difference of seismic demand is in the order of 1% -6% and that at the time design with the results of either the E.030 standard versions, causes no problem from the economic standpoint. It is also noted that there are parameters that limit the irregularity in the building and improve the seismic performance of this.
It ends with the development of structural plans of all the building that is one of the key objectives of this research.
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GFRP-reinforced concrete columns under simulated seismic loading / Colonnes en béton armé renforcées de PRFV sous un chargement sismique simuléMohammed, Mohammed Gaber Elshamandy January 2017 (has links)
Abstract : Steel and fiber-reinforced-polymer (FRP) materials have different mechanical and physical characteristics. High corrosion resistance, high strength to weight ratio, non-conductivity, favorable fatigue enable the FRP to be considered as alternative reinforcement for structures in harsh environment. Meanwhile, FRP bars have low modulus of elasticity and linear-elastic stress-strain curve. These features raise concerns about the applicability of using such materials as reinforcement for structures prone to earthquakes. The main demand for the structural members in structures subjected to seismic loads is dissipating energy without strength loss which is known as ductility. In the rigid frames, columns are expected to be the primary elements of energy dissipation in structures subjected to seismic loads.
The present study addresses the feasibility of reinforced-concrete columns totally reinforced with glass-fiber-reinforced-polymer (GFRP) bars achieving reasonable strength and the drift requirements specified in various codes. Eleven full-scale reinforced concrete columns—two reinforced with steel bars (as reference specimens) and nine totally reinforced with GFRP bars—were constructed and tested to failure. The columns were tested under quasi-static reversed cyclic lateral loading and simultaneously subjected to compression axial load. The columns are 400 mm square cross-section with a shear span 1650 mm. The specimen simulates a column with 3.7 m in height in a typical building with the point of contra-flexure located at the column mid-height. The tested parameters were the longitudinal reinforcement ratio (0.63, 0.95 and 2.14), the spacing of the transverse stirrups (80, 100, 150), tie configuration (C1, C2, C3 and C4), and axial load level (20%, 30% and 40%).
The test results clearly show that properly designed and detailed GFRP-reinforced concrete columns could reach high deformation levels with no strength degradation. An acceptable level of energy dissipation compared with steel-reinforced concrete columns is provided by GFRP reinforced concrete columns. The dissipated energy of GFRP reinforced concrete columns was 75% and 70% of the counter steel columns at 2.5% and 4% drift ratio respectively. High drift capacity achieved by the columns up to 10% with no significant loss in strength. The high drift capacity and acceptable dissipated energy enable the GFRP columns to be part of the moment resisting frames in regions prone to seismic activities. The experimental ultimate drift ratios were compared with the estimated drift ratios using the confinement Equation in CSA S806-12. It was found from the comparison that the confinement Equation underestimates values of the drift ratios thus the experimental drift ratios were used to modify transverse FRP reinforcement area in CSA S806-12. The hysteretic behavior encouraged to propose a design procedure for the columns to be part of the moderate ductile and ductile moment resisting frames. The development of design guidelines, however, depends on determining the elastic and inelastic deformations and on assessing the force modification factor and equivalent plastic-hinge length for GFRP-reinforced concrete columns. The experimental results of the GFRP-reinforced columns were used to justify the design guideline, proving the accuracy of the proposed design equations. / L’acier et les matériaux à base de polymères renforcés de fibres (PRF) ont des caractéristiques physiques et mécaniques différentes. La résistance à la haute corrosion, le rapport résistance vs poids, la non-conductivité et la bonne résistance à la fatigue font des barres d’armature en PRF, un renforcement alternatif aux barres d’armature en acier, pour des structures dans des environnements agressifs. Cependant, les barres d’armature en PRF ont un bas module d’élasticité et une courbe contrainte-déformation sous forme linéaire. Ces caractéristiques soulèvent des problèmes d'applicabilité quant à l’utilisation de tels matériaux comme renforcement pour des structures situées en forte zone sismique. La principale exigence pour les éléments structuraux des structures soumises à des charges sismiques est la dissipation d'énergie sans perte de résistance connue sous le nom de ductilité. Dans les structures rigides de type cadre, on s'attend à ce que les colonnes soient les premiers éléments à dissiper l'énergie dans les structures soumises à ces charges.
La présente étude traite de la faisabilité des colonnes en béton armé entièrement renforcées de barres d’armature en polymères renforcés de fibres de verre (PRFV), obtenant une résistance et un déplacement latéral raisonnable par rapport aux exigences spécifiées dans divers codes. Onze colonnes à grande échelle ont été fabriquées: deux colonnes renforcées de barres d'acier (comme spécimens de référence) et neuf colonnes renforcées entièrement de barres en PRFV. Les colonnes ont été testées jusqu’à la rupture sous une charge quasi-statique latérale cyclique inversée et soumises simultanément à une charge axiale de compression. Les colonnes ont une section carrée de 400 mm avec une portée de cisaillement de 1650 mm pour simuler une colonne de 3,7 m de hauteur dans un bâtiment typique avec le point d’inflexion situé à la mi-hauteur. Les paramètres testés sont : le taux d’armature longitudinal (0,63%, 0,95% et 2,14 %), l'espacement des étriers (80mm, 100mm, 150 mm), les différentes configurations (C1, C2, C3 et C4) et le niveau de charge axiale (20%, 30 % et 40%).
Les résultats des essais montrent clairement que les colonnes en béton renforcées de PRFV et bien conçues peuvent atteindre des niveaux de déformation élevés sans réduction de résistance. Un niveau acceptable de dissipation d'énergie, par rapport aux colonnes en béton armé avec de l’armature en acier, est atteint par les colonnes en béton armé de PRFV. L'énergie dissipée des colonnes en béton armé de PRFV était respectivement de 75% et 70% des colonnes en acier à un rapport déplacement latéral de 2,5% et 4%. Un déplacement supérieur a été atteint par les colonnes en PRFV jusqu'à 10% sans perte significative de résistance. La capacité d’un déplacement supérieur et l’énergie dissipée acceptable permettent aux colonnes en PRFV de participer au moment résistant dans des régions sujettes à des activités sismiques. Les rapports des déplacements expérimentaux ultimes ont été comparés avec les rapports estimés en utilisant l’Équation de confinement du code CSA S806-12. À partir de la comparaison, il a été trouvé que l’Équation de confinement sous-estime les valeurs des rapports de déplacement, donc les rapports de déplacement expérimentaux étaient utilisés pour modifier la zone de renforcement transversal du code CSA S806-12. Le comportement hystérétique encourage à proposer une procédure de conception pour que les colonnes fassent partie des cadres rigides à ductilité modérée et résistant au moment. Cependant, l'élaboration de guides de conception dépend de la détermination des déformations élastiques et inélastiques et de l'évaluation du facteur de modification de la force sismique et de la longueur de la rotule plastique pour les colonnes en béton armé renforcées de PRFV. Les résultats expérimentaux des colonnes renforcées de PRFV étudiées ont été utilisés pour justifier la ligne directrice de conception, ce qui prouve l’efficacité des équations de conception proposées.
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Adaptation de la méthode de corrélation d'images numériques pour la gestion des discontinuités du milieu et de la transformation / Adaptation of the digital image correlation method for handling material and transformation discontinuitiesHusseini, Hassan Al 04 July 2014 (has links)
Le travail présenté dans ce mémoire consiste à adapter la méthode de corrélation d'images numériques (CIN) pour la gestion des discontinuités du milieu et de la transformation. Le cadre d'utilisation des méthodes optiques de mesure i.e. celui de la mécanique des milieux continus, impose une continuité matérielle : i) du domaine et ii) de la transformation. Pour traiter les discontinuités en question, on peut reconsidérer la continuité (milieu et transformation) par morceaux. Dans le cadre de la CIN, cela se traduit par la possibilité d'adapter localement la forme et la taille des fenêtres de corrélation à la zone d'intérêt et à sa cinématique. Pour ce faire, il est possible d'utiliser des masques : un masque-objet pour traiter les discontinuités du milieu et un masque-discontinuité pour traiter les discontinuités de la transformation. Cependant, avant l'implémentation des masques dans la procédure de corrélation, plusieurs essais expérimentaux de déplacement sur des modèles comportant les deux types de discontinuité, ont été conduits. Ces essais ont permis de prouver l'influence des discontinuités sur la dégradation de la précision de mesure par CIN. Ensuite, des essais de traction ont été menés sur une éprouvette en polycarbonate conduisant à un mode I d'ouverture ou de fermeture de fissure. Après l'implémentation des masques dans le logiciel de corrélation Correla, le calcul des champs de déplacement et de déformation a été opéré avec succès à la surface de cette éprouvette, démontrant ainsi l'efficacité de la CIN adaptée. / The development of the digital image correlation method (DIC) for the management of discontinuities of the material and the transformation is discussed in this thesis. As we know, the framework for the use of the optical measurement methods i.e. of continuum mechanics requires a continuity of: i) domain and ii) transformation. To treat those discontinuities, we can consider a piecewise continuity (material and transformation). In the case of DIC method, this can be done by adapting locally the shape and size of the correlation subsets to the zone of interest and its kinematics. A novel way to do it, is by using masks: an object mask to process material discontinuities and a discontinuity mask to process transformation discontinuities. However before the implementation of masks in the correlation process, several experimental displacement tests on models reproducing the two types of discontinuity at small scale were performed. Those tests proved the influence of discontinuities on the degradation of the measurement accuracy by DIC. Then, tensile tests were conducted on a polycarbonate made specimen knowing a mode I opening or closing crack. After implementing masks in the correlation software Correla, the calculation of displacement and deformation fields was successfully performed on the surface of this specimen for all its edges, demonstrating the effectiveness of the adapted DIC.
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