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Posicionamento por ponto preciso estático e cinemático: implementação e análiseFaustino, Renata Cristina [UNESP] 31 October 2006 (has links) (PDF)
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faustino_rc_me_prud.pdf: 956028 bytes, checksum: 4518bd21cfc75ed14c3e4e793a14ec55 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Nesta dissertação investiga-se o Posicionamento por Ponto Preciso (PPP), nos modos estático e cinemático, utilizando o Filtro de Kalman Estendido. Foram corrigidos os erros devido aos efeitos da refração troposférica, relatividade, movimento de rotação da Terra, variações das marés terrestres, correção do centro de fase da antena do satélite e fase Wind- up. Os efeitos devido à ionosfera foram minimizados através da combinação linear Ion-Free. A perda de ciclo foi detectada através da combinação linear widelane, envolvendo as duas observáveis: fase da onda portadora e pseudodistância. Quando a perda de ciclo é detectada, uma nova ambigüidade é inicializada no lugar da antiga. As implementações foram realizadas no software FILTER_FCT, em desenvolvimento na FCT/UNESP, o qual processava apenas a pseudodistância. Visando mostrar a acurácia que pode ser obtida com o PPP, foram realizados três experimentos: PPP no modo estático, PPP estático simulando o modo cinemático e PPP cinemático. No primeiro e no segundo experimentos foram utilizados dados das estações GPS: PPTE, VICO, RIOD e FORT, pertencentes à Rede Brasileira de Monitoramento Contínuo (RBMC), e da estação FRDN, localizada em Fredericton, no Canadá. No terceiro experimento foram utilizados dados do receptor GPS a bordo do satélite CHAMP. No PPP estático, utilizou-se como estratégia de processamento a modificação da variância das coordenadas e do relógio do receptor na matriz de variância-covariância do Filtro de Kalman Estendido. Verificou-se uma discrepância em relação às coordenadas consideradas verdadeiras na ordem de decímetros, com exceção das estações VICO e RIOD, que foram da ordem de centímetros. / In this dissertation the Precise Point Positioning (PPP), in static and kinematic modes, using Extended Kalman Filter is investigated. The errors due to troposphere refraction, relativity, movement of Earth's rotation, tide loading, satellite antenna phase center offset and phase wind-up were corrected. The effects due to ionosphere were minimized through the Ionospheric-Free linear combination. The widelane combination, involving phase and pseduorange, was used to detect cycle slips. When a cycle slip is detected, a new ambiguity is initialized in the place of the old one. The implementations were accomplished in the FILTER_FCT software. To show the accuracy in the PPP, three experiments were accomplished: PPP in the static mode, PPP in the static mode simulating the kinematic mode and PPP in kinematic mode. In the first and second experiments, data from PPTE, VICO, RIOD and FORT stations belonging to Brazilian Network for Continuous Monitoring (RBMC), and FRDN station located in Fredericton, Canada, were used. In the third experiment data from a GPS receiver on board of the CHAMP satellite were used. In static PPP, the modification of the coordinates variance and the receiver clock was used as processing strategy. The discrepanc ies obtained in the static positioning were on the order of decimeters, except for VICO and RIOD stations where they were on the order of centimeters. When the clock receiver variance was increased from (3.300)ø mø to (10.000)ø mø , the values of the discrepancies also increased, on the order of centimeters. Then, there is influence of the receiver clock variance in the estimated coordinates. The residual part of the tropospheric effects was estimated with the introduction of a scale factor in the processing.
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An?lise estrutural da deforma??o cenoz?ica na Bacia de Cumuruxatiba (BA)Ferreira, Talles Souza 03 September 2010 (has links)
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Previous issue date: 2010-09-03 / The Cumuruxatiba basin is located at the southern coast State of Bahia in
northeastern of Brazil. This basin was formed in distensional context, with rifting
and subsequent thermal phase during Neocomian to late Cretaceous. At Cenozoic
ages, the Abrolhos magmatism occurs in the basin with peaks during the
Paleocene and Eocene. In this period, there was a kinematic inversion in the
basin represented by folds related to reverse faults. Structural restoration of
regional 2D seismic sections revealed that most of the deformation was
concentrated at the beginning of the Cenozoic time with the peak at the Lower
Eocene. The post-Eocene is marked by a decrease of strain rate to the present.
The 3D structural modeling revealed a fold belt (trending EW to NE-SW)
accommodating the deformation between the Royal Charlotte and Sulphur
Minerva volcanic highs. The volcanic eruptions have caused a differential
overburden on the borders of the basin. This acted as the trigger for halokinesis,
as demonstrated by physical modeling in literature. Consequently, the
deformation tends to be higher in the edges of the basin. The volcanic rocks
occur mainly as concordant structures (sills) in the syn-tectonic sediment
deposition showing a concomitant deformation.
The isopach maps and diagrams of axis orientation of deformation
revealed that most of the folds were activated and reactivated at different times
during the Cenozoic. The folds exhibit diverse kinematic patterns over time as
response to behavior of adjacent volcanic highs. These interpretations allied with
information on the petroleum system of the basin are important in mapping the
prospects for hydrocarbons / A Bacia de Cumuruxatiba est? localizada no extremo sul da costa do
Estado da Bahia, no Nordeste do Brasil. Esta bacia foi formada em ambiente
distensional, com rifteamento e posterior fase termal durante o Neocomiano at?
final do Cret?ceo. Durante o Cenoz?ico ocorre o magmatismo de Abrolhos na
bacia com picos durante o Paleoceno e Eoceno. Neste per?odo ocorre uma
invers?o cinem?tica na bacia representada por dobras relacionadas a falhas
reversas. Restaura??es estruturais regionais de se??es s?smicas 2D, revelaram
que a maior parte da deforma??o est? concentrada no inicio do Cenoz?ico com o
pico no Eoceno Inferior. O per?odo p?s-Eoceno ? marcado pela diminui??o da
taxa de deforma??o at? o presente.
A modelagem estrutural 3D revelou uma frente de dobras (de orienta??o
E-W variando para NE-SW) acomodando a deforma??o entre os altos vulc?nicos
de Royal Charlotte e Sulphur Minerva. Os derrames vulc?nicos causaram uma
sobrecarga diferencial nas bordas da bacia que serviu de gatilho para atua??o da
halocinese, como j? demonstrado em modelagens f?sicas na literatura.
Consequentemente, a deforma??o tende a ser maior na bordas da bacia. As
rochas vulc?nicas ocorrem principalmente como estruturas concordantes (sills)
nos sedimentos sin-tect?nicos revelando uma deposi??o concomitante ?
deforma??o.
O estudo dos mapas de is?pacas e diagramas com orienta??o do eixo de
deforma??o revelaram que maior parte das dobras foram ativadas e reativadas em
diferentes per?odos durante o Cenoz?ico. As dobras apresentam padr?es
cinem?ticos variados ao longo do tempo que refletem a atua??o diferencial dos
altos vulc?nicos adjacentes. Estas interpreta??es aliadas a informa??es sobre os
sistemas petrol?feros da bacia s?o importantes no mapeamento dos prospectos
para hidrocarbonetos
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Efeitos da inclina??o da esteira na marcha de indiv?duos hemipar?ticos cr?nicosMoreno, Cinthia de Carvalho 29 July 2009 (has links)
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Previous issue date: 2009-07-29 / Objective: To examine the effects of treadmill inclinations on the walking of hemiparetic chronic subjects. Design: Observational descriptive study. Location: Laboratory of human movement analysis. Participants: Eighteen subjects, 10 men and 8 women were evaluated, with a mean age of 55.3 ? 9.3 years and the time since the injury of about 36 ? 22.8 months. Intervention: Not applicable. Main Outcome Measures: All subjects were evaluated for functional independence (Functional Independence Measure - FIM) and balance (Berg Balance Scale). Angular variations of the hips, knees and ankles in the sagittal plane were observed, as well as the speed of the movement (m/s), cadence (steps/min), stride length (m), cycle time (s), step time on the paretic leg and on the non-paretic leg (s), support phase time and balance phase time on the paretic leg (s) and the ratio of symmetry inter-limb as subjects walked on a treadmill at three conditions of inclination (0%, 5% and 10% ). Results: There were angular increases in the initial contact of the hip, knee and ankle, amplitude increase in the hip between 0% and 10% (37.83 ? 5.23 versus 41.12 ? 5.63, p < 0,001) and 5% and 10% (38.80 ? 5.96 versus 41.12 ? 5.63, p = 0,002), amplitude increases in the knee between 0% and 10% (47.51 ? 15.07 versus 50, 30 ? 12.82, p = 0,040), extension decreases in the hip, dorsiflexion increases in the balance phase and in the time of support phase from 0% to 5% (0.83 ? 0.21 versus 0.87 ? 0, 20, p = 0,011) and 0% and 10% (0.83 ? 0.21 versus 0.88 ? 0.23, p = 0,021). Conclusion: The treadmill inclination promoted angle changes as such as the increase of the angle of the hip, knee and ankle during the initial contact and the balance phase and the increase of the range of motion of the hip and knee; furthermore, it also promoted the increase of the support time of the paretic lower limb / Objetivo: Analisar os efeitos da inclina??o da esteira el?trica na marcha de indiv?duos com hemiparesia cr?nica. Desenho: Estudo observacional descritivo. Local: Laborat?rio de an?lise do movimento humano da UFRN. Participantes: Foram avaliados 18 indiv?duos, 10 homens e 8 mulheres, com m?dia de idade de 55,3 ? 9,3 anos e tempo de les?o de 36 ? 22,8 meses. Interven??o: N?o se aplica. Medidas: Todos os sujeitos foram avaliados quanto ? independ?ncia funcional (Medida de Independ?ncia Funcional - MIF) e equil?brio (Escala de Equil?brio de Berg). Foi observada a varia??o angular do quadril, joelho e tornozelo no plano sagital e tamb?m a velocidade da marcha (m/s), cad?ncia (passos/min), comprimento da passada (m), tempo do ciclo (s), tempo do passo da perna par?tica e n?o-par?tica (s), tempo de apoio e tempo de balan?o da perna par?tica (s) e raz?o de simetria entre membros enquanto os indiv?duos caminhavam na esteira em tr?s condi??es de inclina??o (0%, 5% e 10%). Resultados: houve aumento do ?ngulo no contato inicial do quadril, joelho e tornozelo, aumento da amplitude do quadril entre 0% e 10% (37,83 ? 5,23 versus 41,12 ? 5,63; p < 0,001) e 5% e 10% (38,80 ? 5,96 versus 41,12 ? 5,63; p = 0,002), aumento da amplitude do joelho entre 0% e 10% (47,51 ? 15,07 versus 50,30 ? 12,82; p = 0,040), diminui??o da extens?o do quadril, aumento da dorsiflex?o no balan?o e aumento no tempo de apoio entre 0% e 5% (0,83 ? 0,21 versus 0,87 ? 0,20; p = 0,011) e 0% e 10% (0,83 ? 0,21 versus 0,88 ? 0,23; p = 0,021). Conclus?o: A inclina??o da esteira promoveu altera??es angulares como o aumento do ?ngulo do quadril, joelho e tornozelo durante o contato inicial e a fase de balan?o e aumento da ADM do quadril e joelho, bem como aumento do tempo de apoio do membro inferior par?tico
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Estudo comparativo da marcha de indiv?duos hemipar?ticos no solo e na esteiraMendes, Luciana de Andrade 07 July 2009 (has links)
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Previous issue date: 2009-07-07 / The purpose of the study was to compare hemiparetic gait overground and on the treadmill. Seventeen chronic stroke patients were included in the study. They walked overground and on a treadmill level at the same speed. The Qualisys Medical AB motion analysis system was used to quantify the joint kinematic of the paretic lower limb and the spatio-temporal parameters on the two conditions: overground walking and treadmill walking on three samples of 5-minutes. During the first sample, the subjects walked on the treadmill with greater cadence, shorter stride length, shorter step time on the lower paretic limb, greater range of motion in the hip and knee, greater knee flexion at the initial contact, more extension of the knee and lower dorsiflexion of the ankle at the stance phase. It is important to emphasize that the maximal knee flexion and ankle dorsiflexion just occurred later on the treadmill. Comparisons between each walking sample on the treadmill hadn t revealed any changes on the gait parameters over time. Nonetheless, when analyzing the third walking sample on the treadmill and overground, some variables showed equivalence as such as the total range of motion of the hip, the knee angle at the initial contact and its maximal extension at the stance phase. In summary, walking on a treadmill, even thought having some influence on the familiarization process, haven t demonstrated a complete change in its characteristics of hemiparetic chronic patients / Este estudo teve como objetivo comparar a marcha de indiv?duos hemipar?ticos no solo e em diferentes per?odos na esteira. Foram inclu?dos 17 indiv?duos hemipar?ticos cr?nicos, os quais deambularam sobre a esteira e solo com a mesma velocidade. O sistema se an?lise do movimento Qualisys Medical AB foi utilizado para quantificar as vari?veis angulares referentes ao membro inferior par?tico e as vari?veis espa?o-temporais nas duas condi??es: marcha no solo e marcha na esteira, sendo esta ?ltima realizada em 3 coletas de 5 minutos. Durante a primeira coleta os sujeitos deambularam na esteira com maior cad?ncia, menor comprimento da passada, menor tempo de passo com o membro inferior par?tico, maior amplitude de movimento para as articula??es do quadril e joelho, maior flex?o do joelho no contato inicial, maior extens?o do joelho e menor dorsoflex?o do tornozelo no apoio. Vale ressaltar que a m?xima flex?o do joelho e a m?xima dorsoflex?o do tornozelo no balan?o ocorreram tardiamente na esteira. Compara??es entre as coletas sobre esteira n?o demonstraram mudan?a na marcha no decorrer do tempo, entretanto, quando confrontada a terceira coleta na esteira com o solo, algumas vari?veis revelaram equival?ncia entre os meios como a amplitude total do quadril, o ?ngulo do joelho no contato inicial e sua m?xima extens?o no apoio. Desta forma, a marcha em esteira mesmo demonstrando uma certa influ?ncia do processo de familiariza??o, n?o apresentou uma mudan?a completa em suas caracter?sticas em indiv?duos com hemiparesia cr?nica
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Efeitos do treino em esteira na marcha com dupla tarefa de indiv?duos com doen?a de Parkinson: ensaio cl?nico controlado randomizadoSousa, Angelica Vieira Cavalcanti de 19 December 2012 (has links)
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Previous issue date: 2012-12-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Background: The gait automaticity loss difficults realization of concurrent activities - Dual Task (DT). In these situations, individuals with Parkinson`s disease (PD) show a significant reduction in gait velocity and stride length, as strides variability and asymmetry increased, factors predisposing to falls. However, recent studies have shown that training involving DT may cause subsequent improvements in gait variables with DT in individuals with PD. The treadmill use was adopted by this study, by promoting greater regularity in step and enhance training. Objective:To investigate immediate effects of gait training associated with cognitive tasks on gait in individuals with PD. Methods: Twenty-two volunteers were randomly divided into two groups: control group (n = 11), who performed gait training on a treadmill for 20 minutes, and the experimental group (n = 11), who performed treadmill gait training for 20 minutes associated with cognitive tasks of verbal fluency, memory, and spatial planning. Participants were evaluated in phase on of antiparkinsonian medication as the demographic, clinical and anthropometric (identification form), cognitive status (Montreal Cognitive Assessment - MoCA), executive function (Frontal Assessment Battery), level of physical disability (Hoehn and Yahr Modified), motor and functional status (Unified Rating Scale for Parkinson`s Disease - UPDRS), and kinematics (Qualisys Motion Capture System). Results: There were not differences between groups, but both showed improvement after the intervention. The control group had an increase in velocity (p = 0.008), stride length (p = 0.04), step length (p = 0.02) and decreased double support time(p = 0.03). The experimental group showed an increase in speed (p = 0.002), stride length (p = 0.008), step length (p = 0.02) and cadence (p = 0.01), as well as a decrease in the width stride (p = 0.001) and total support time (p = 0.02). As the angular variables, the experimental group had a significant increase in the initial contact angle of ankle (p = 0.01). Conclusion: The gait training combined with cognitive activities didn`t provide significant improvements in gait variables with DT, but this study was the first to demonstrate that gait training on treadmill as simple task minimized the negative interference of DT in PD / Introdu??o: A perda na automaticidade da marcha dificulta a realiza??o de atividades concorrentes - Dupla Tarefa (DT). Nessas situa??es, indiv?duos com Doen?a de Parkinson (DP) apresentam significativa redu??o na velocidade da marcha e no comprimento do passo, assim como aumento na variabilidade entre as passadas e na assimetria, fatores predisponentes a quedas. No entanto, estudos recentes t?m demonstrado que o treinamento envolvendo DT pode ocasionar posteriores melhoras nas vari?veis da marcha com DT em indiv?duos com DP. O uso da esteira foi adotado por este estudo, por promover maior regularidade no passo e potencializar o treino. Objetivo: Investigar os efeitos imediatos do treino de marcha em esteira associado a tarefas cognitivas na marcha com DT de indiv?duos com DP. Materiais e m?todos: Vinte e dois volunt?rios foram divididos aleatoriamente em dois grupos: Grupo Controle (n=11), que realizou treino de marcha em esteira durante 20 minutos; e Grupo Experimental (n=11), que realizou treino de marcha em esteira durante 20 minutos associado a tarefas cognitivas de flu?ncia verbal, mem?ria e planejamento espacial. Os participantes foram avaliados na fase on do medicamento antiparkinsoniano quanto a dados demogr?ficos, cl?nicos e antropom?tricos (formul?rio de identifica??o), condi??o cognitiva (Montreal Cognitive Assessment - MoCA), fun??es executivas (Bateria de Avalia??o Frontal), n?vel de incapacidade f?sica (Escala de Hoehn e Yahr Modificada), estado motor e funcional (Escala Unificada de Avalia??o para a Doen?a de Parkinson UPDRS), e cinemetria (Qualisys Motion Capture System). Resultados: N?o houve diferen?as entre os grupos, mas ambos apresentaram melhoras ap?s a interven??o. O grupo controle obteve aumento na velocidade (p=0,008), no comprimento da passada (p=0,04), no comprimento do passo (p=0,02) e diminui??o no tempo de duplo suporte (p=0,03). O grupo experimental apresentou aumento na velocidade (p=0,002), no comprimento da passada (p=0,008), no comprimento do passo (p=0,02) e na cad?ncia (p=0,01), assim como diminui??o na largura da passada (p=0,001) e no tempo total de apoio (p=0,02). Quanto ?s vari?veis angulares, o grupo experimental teve um aumento significativo no ?ngulo do contato inicial do tornozelo (p=0,01). Conclus?o: O treino de marcha associado a atividades cognitivas n?o proporcionou melhoras significativas nas vari?veis da marcha com DT, mas este estudo foi o primeiro a demonstrar que o treino de marcha como tarefa simples na esteira minimizou a interfer?ncia negativa da DT na DP
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Desenvolvimento de um sistema de captura e análise de movimentos baseado em técnicas de visão computacional / Developing of a motion capture system based on computer vision techniquesPinheiro, Alan Petrônio 30 April 2008 (has links)
The purpose of this study was investigate the measurement techniques of human
movement and to develop a system capable of capturing and reconstructing the movement
trajectory on real world. The devised system uses video cameras to record the movement
and a computer program to process video footage assessing the movement trajectory and
calculating its kinematical variables. Those data are showed by the program as graphics or
animation which simulates the reconstructed movement. To reach these objectives, the
system used techniques from image processing, computer vision and anthropometric
models. In the end of this work, it is exhibited an experimental evaluation of the precision
and accuracy of the system and some case studies to show its potential. / O propósito deste estudo foi pesquisar as técnicas de medição do movimento humano e
desenvolver um sistema capaz de capturar e reconstruir a trajetória do movimento no
espaço. O sistema desenvolvido utiliza câmeras de vídeo para registrar o movimento e um
programa de computador capaz de processar as imagens extraídas dos vídeos de forma a
estimar a trajetória do movimento e calcular as suas variáveis cinemáticas. Estes dados são
exibidos pelo programa na forma de gráficos ou animações que reconstroem o movimento
capturado. Para alcançar estes objetivos, o sistema utilizou técnicas de processamento de
imagens, visão computacional, cálculos numéricos e modelos antropométricos do corpo
humano. Ao final desta dissertação é feita uma avaliação experimental da precisão e
exatidão do sistema proposto e alguns estudos de casos que tiveram como objetivo
demonstrar o potencial deste sistema. / Mestre em Ciências
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Retroanálise numérica da convergência de uma escavação subterrânea em rocha (caso estudo: TAJ UHE Simplício) / Back-analysis numerical of convergence of underground escavation in rock (Case Study: TAJ UHE Simplicio)VISSOTTO JÚNIOR, Lucas Alberto 09 June 2009 (has links)
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Previous issue date: 2009-06-09 / Currently, the increasing demand for great workmanships in Brazil, had become an impediment for the development of Brazil. The Geotechnical Engineering is considered an
essential tool, in great workmanships (hydroelectric power plants, subways, tunnels, etc.) supplying technical support for design and construction. In this context, the underground
excavations in rock have increased too much. This work presents a study of the behavior of the closer of an underground excavation in rock, where it was considered as case study, Simplício hydroelectric power plant, located in the Paranaíba do Sul river, in frontiers of the States of Rio de Janeiro and Minas Gerais. By means of laboratory tests with samples of intact rock and survey mapping of discontinuities, was characterizes the rock mass. Establishing the principal geomechanic parameters and estimating the in-situ stress state of the rock mass, then was chose the geomechanical model and made a numerical simulation of the excavation process tunnel help downstream of tunnel 3. For the tunnel study was conducted a numerical axial analysis symmetry of the relaxation of the excavated mass on the distance from the face of excavation, to determine the moment of installation and simulate a support of the tunnel closer. For the carried out simulation, the rock mass behaved only in the
elastic range, finding closer the results of the simulation, the results on the field by monitoring the tunnel. It was observed that for the degree of alteration of the studied mass, the rupture could occur for the rock as well for the discontinuities, depending on the wedges formed for the discontinuities families and the support type applied in the rock mass / Atualmente, a crescente demanda por grandes obras no Brasil, tem se tornado um gargalo para o desenvolvimento. A Geotecnia se coloca como uma ferramenta essencial, em
obras de infra-estrutura (usinas hidrelétricas, metrôs, túneis etc.); fornecendo suporte técnico para projetos e execução de obras. Neste contexto, as escavações subterrâneas em rocha têm aumentado muito na última década. Esta dissertação apresenta um estudo do comportamento
da convergência de uma escavação subterrânea em rocha, onde foi considerado como estudo de caso, a Usina Hidroelétrica (UHE) de Simplício/Anta, localizada no Rio Paraíba do Sul, na divisa entre os Estados do Rio de Janeiro e Minas Gerais. Por meio de ensaios em laboratório com amostras de rocha intacta, levantamento estrutural da rocha, e resultado de ensaios em campo foi caracterizado o maciço rochoso. Determinados os principais parâmetros geomecânicos e estimado o estado das tensões originais da rocha, foi então escolhido o modelo geomecânico e realizado a simulação numérica do processo de escavação do túnel auxiliar de jusante do túnel 3 (TAJ TN3). Para o túnel estudado foi realizado uma analise numérica axissimetrica da relaxação do maciço escavado em relação a distância da face de escavação, para determinação do momento da instalação do suporte e simulação bidimensional da convergência do túnel. Para a simulação realizada o maciço comportou-se apenas na faixa elástica, aproximando os resultados obtidos pela simulação, dos resultados em campo através do monitoramento da convergência. Foi observado que para o grau de alteração do maciço estudado, os modos de ruptura, podem ser tanto pela rocha quanto pelas descontinuidades, dependendo das cunhas formadas pelas famílias de descontinuidades e pelo tipo de suporte aplicado no maciço rochoso
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Méthodologie de modélisation des systèmes mécatroniques complexes à partir du multi-bond graph : application à la liaison BTP-fuselage d’un hélicoptère / Methodology for modeling complex mecatronics systems with multi-bond graph : application to the helicopterBoudon, Benjamin 12 December 2014 (has links)
De par le fonctionnement de son rotor, l'hélicoptère est le siège de vibrations mécaniques importantes impactant notamment la fatigue des pièces mécaniques et le confort des passagers. La liaison BTP-Fuselage équipé du système SARIB est un système anti-vibratoire qui permet d'atténuer mono-fréquentiellement les vibrations transmises au fuselage. Des solutions intelligentes semi-actives sont donc étudiées afin que la filtration soit réglable en fonction des vibrations excitatrices. Ce type d'études souffre, par contre, d'un manque d'outils et de méthodes indispensables, d'une part, à la modélisation de systèmes mécaniques complexes et d'autre part, à l'élaboration d'une liaison intelligente. Ces travaux proposent une démarche de modélisation à partir d'un outil de modélisation structurel tel que le multi-bond graph (MBG) permettant une vision global et modulaire pour l'étude de systèmes mécaniques complexes tels qu'on peut les trouver sur un hélicoptère. Dans un premier temps, une analyse des outils de modélisation conduisant au choix du MBG a été présentée. Dans un second temps, les développements ont porté sur la modélisation MBG de la liaison BTP/ Fuselage 3D d'un banc d'essai réel qui a été conçu et réalisé au sein du laboratoire. Cette liaison est un système mécanique cinématiquement bouclé. Les équations de la dynamique d'un tel système forment un système d'équations algébro-différentiel (DAE) nécessitant des techniques de résolution spécifiques. Le modèle MBG de la liaison BTP-fuselage entier a été simulé à l'aide du logiciel 20-sim. Les résultats obtenus ont été vérifiés à l'aide du logiciel multicorps LMS Virtual Lab. Une comparaison des résultats obtenus par les deux méthodes a donné, pour différents cas d'excitations de la BTP (pompage, roulis, tangage), une corrélation très satisfaisante. Dans un troisième temps, le modèle MBG a été exploité pour la mise en place d'un dispositif de contrôle semi-actif. Le modèle du dispositif SARIB développé également sous 20-sim permet de régler la position des masses mobiles en fonctionnement de manière à minimiser le niveau de vibratoire du fuselage. L'algorithme de contrôle (algorithme de gradient) permet de calculer les consignes de position des masses mobiles sur les batteurs SARIB. La position des masses mobiles actionnée par un moteur électrique à courant continu et un système vis-écrou est ensuite asservie aux consignes générées par l'algorithme de contrôle. Enfin, la commande a pu être mise en place sur un modèle bond graph non-linéaire qui n'a pas nécessité une linéarisation en vue d'une transformation en fonction de transfert. / Due to the operation of the rotor, the helicopter is subject to important vibrations affecting namely the fatigue of mechanical parts and the passengers comfort. The MGB-Fuselage joint equipped with the DAVI system is an anti-vibration system that helps to reduce, in a single frequency way, vibrations transmitted to the fuselage. Semi-active intelligent solutions are studied so that the filtering can be adjusted according to the vibration sources. Such studies suffer from a lack of tools and necessary methods, firstly, for the design of complex mechanical systems and secondly, for the development of an intelligent joint. This work proposes a modeling approach using a structural modeling tool : the multi-bond graph (MBG) which offers a global and modular view for the study of complex mechatronic systems such as helicopter. At first, an analysis of modeling tools leading to the selection of MBG is presented. Secondly, developments have focused on the MBG modeling of the 3D MGB-fuselage joint of an experimental setup which was designed and built in the laboratory. This joint is a mechanical system with kinematic loops. The equations of the dynamics of such system are a differential-algebraic system (DAE) requiring specific solving methods. The MBG model of the MGB-fuselage was simulated using the 20-sim software. The results were verified using the multibody software LMS Virtual Lab. A comparison of results obtained by the two methods led to a very good correlation to various cases of excitations of the MGB (pumping, roll, pitch). Thirdly, the MBG model was used for the establishment of semi-active control system. The model of the DAVI device also developed in 20-sim allows to adjust the position of the moving masses in operation so as to minimize the level of vibration of the fuselage. The control algorithm (gradient algorithm) enables to calculate the setpoint positions of the moving masses on the DAVI beaters. The position of the moving masses driven by an electric DC motor and a screw-nut system is then controlled to the setpoints generated by the control algorithm. Finally, the command could be implemented on a non-linear bond graph model which did not require a linearization to get a transfer function.
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Développements expérimentaux et numériques pour la caractérisation des champs cinématiques de la coupe de l’acier 100 CrMo 7 durci pour la prédiction de l’intégrité de surface / Experiemental and numerical developments for the kinematic field characterizations to predict surface integrity during 100 CrMo 7 hardened steel cuttingBaizeau, Thomas 13 December 2016 (has links)
Aujourd'hui, les méthodes de corrélation d'images sont largement utilisées pour la caractérisation et le suivi temporel des essais mécaniques. Cependant dans le domaine de l'usinage, ces méthodes sont très peu employées pour l'étude en pointe d'outil de la coupe par manque d'accessibilité, de la faible taille de la zone observée et des fortes déformations dans la zone de coupe. Dans cette thèse, nous mettons en application la technique de corrélation d'images pour l'étude et la caractérisation des champs cinématiques induits dans la matière usinée, durant des essais de coupe conduits avec des conditions opératoires représentatives des opérations industrielles. Ces conditions nous ont permis de développer, en premier lieu, des outils expérimentaux et numériques. Puis, les performances du dispositif expérimental ainsi que les incertitudes de corrélation ont été quantifiées. Différentes stratégies d'exploitation des images ainsi que des outils numériques pour la mesure des caractéristiques de la coupe sont proposés. Ensuite, nous avons développé un outil de corrélation d'images intégrée pour la mesure des efforts dynamiques grâce à un modèle analytique. Pour valider l'ensemble des méthodes, des essais de rabotage, d'abord dans un alliage d'aluminium, puis dans un acier 100~CrMo~7 traité thermiquement, ont été conduits. Ils ont permis de quantifier les champs cinématiques ainsi que les caractéristiques de la coupe. Enfin ces outils ont été appliqués pour la prédiction de l'intégrité de surface engendrée par une géométrie 3D d'outil de coupe dans le matériau dur. / Nowadays, digital image correlation (DIC) methods are widely employed to the mechanical testing characterization and their temporal monitoring. However in the machining field, to study the cutting process at the tool edge, these methods are not commonly applied due to the poor accessibility, the size of the observed area and the large strain occurring herein. In this study, the kinematic fields induced in the material by the cutting process are characterized and analyzed at industrial cutting conditions. In order to take and treat the pictures of the cut, experimental and numerical techniques have been first established. Then, the experimental setup performances and the uncertainties of the DIC were quantified. Different images selection strategies for the DIC and numerical post-processing algorithm for measuring the characteristics of the cut were proposed. Furthermore, a DIC integrated approach based on an analytical model was developed to record dynamics cutting forces. Trials in orthogonal configuration were performed and analyzed to validate the developed procedures first in an aluminium alloy, then in a 100~CrMo~7 hardened steel. The kinematics fields and the macroscopic data of the cut were successfully measured thanks to these tools. Finally, they were used for the prediction of the surface integrity induced by a 3D cutting edge in the hard material.
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Développement d'une technique de tomographie par découpage optique rotatif pour la mesure résolue en temps de champs cinématiques 3D par corrélation d'images volumiques / Development of a new optical rotating scanning tomography method adapted totime-resolved kinematic fields measurement by digital volume correlationMorandi, Pierre 12 December 2014 (has links)
Pour l'étude d'une structure solide ou d'un matériau, l'analyse expérimentale permet d'obtenir des grandeurs mécaniques qui permettent de comprendre leurs comportements ou encore de valider des résultats issus d'une simulation numérique. Ces grandeurs peuvent être de différentes natures (contraintes, déformations...) et être localisées de différentes manières dans l'espace (2D, 3D) et dans le temps (statique, dynamique). Le bilan des techniques actuelles d'analyse expérimentale en mécanique des solides révèle un besoin concernant l'acquisition d'une structure en tous points avec une résolution élevée à la fois spatialement et temporellement. L'objectif des travaux menés au cours de cette thèse est le développement d'une nouvelle technique d'acquisition capable d'acquérir un volume de matière de quelques centimètres de côté en moins d'une seconde avec une précision spatiale inférieure à 0.1mm. Les volumes obtenus doivent avoir une qualité suffisamment élevée pour être couplés à la technique de Corrélation d'Images Volumiques (DVC) permettant d'obtenir les déplacements ainsi que le tenseur des déformations de Green-Lagrange complet au coeur de la matière. Un nouveau procédé d'acquisition baptisé Optical Rotating Scanning Tomography (ORST) et basé sur le découpage optique a été développé. Après l'avoir décrit mathématiquement, un système spécifique synchronisé avec une caméra rapide a été conçu. La méthode a été appliquée sur deux essais mécaniques : traction continue et contact entre un galet roulant et un bloc. L'analyse des résultats a montré que l'ORST est capable d'analyser l'évolution des champs de déformations à la fois au coeur du volume et résolue en temps. / To study of a solid structure or a material, an experimental analysis can be used to get mechanical fields in order to understand the mechanical behaviour or to validate simulation results. Different kind of fields can be obtained (stress, strain) in different spatial (2D, 3D) or temporal referential (static, dynamic). Current techniques are not able to acquire the whole volume of a structure with a high spatial and temporal resolution. The objective of this work is to develop a new volume acquisition technique able to capture a volume with a characteristic edge size of several centimetres in less than 1 second with a spatial accuracy less than 0.1mm. Reconstructed volumes need to have a good quality to be used with the Digital Volume Correlation (DVC) in order to provide displacement fields and the full Green-Lagrange tensor in the whole volume. A new acquisition technique called Optical Rotating Scanning Tomography (ORST) based on the optical scanning technique has been developed. A mathematical description has been achieved and then a special device has been manufactured. This device is synchronized with a high speed CCD camera in order to perform time-resolved acquisition. This new technique has been used to study two mechanical tests. The first is a traction test with a continuous loading, and the second concerns a wheel rolling over a solid bloc. Experimental results of these applications show that ORST technique is able to analyse displacement and strain fields in the whole volume and in a time-resolved way.
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