Made available in DSpace on 2016-08-15T20:31:23Z (GMT). No. of bitstreams: 1 VanessaRMO_DISSERT.pdf: 1127022 bytes, checksum: 07a116e7740f17e848fd3a76785ea47b (MD5) Previous issue date: 2014-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / ABSTRACT - The objective of this study was to evaluate production and egg quality of laying hens Isa Label fed different levels of sunflower meal, the infrared thermography and productive characteristics of laying hens in semi-intensive production system in tropical conditions. One hundred and twenty-eight laying hens with early age of 28 weeks, during 16 weeks of evaluation, distributed in a completely randomized design in 16 boxes with 8 birds per experimental unit were used. The treatments consisted in a control diet (RCO) and three diets containing sunflower meal in substitution for soybean meal, based on the crude protein levels of 10, 20 and 30% (FG10, FG20, FG30) , being all diets based on the nutritional requirements of the laying hens. During the total period of review there was no difference (p> 0.05) between the levels of substitution of crude protein of soybean meal by sunflower meal on productive performance and egg quality of laying hens. The economic analysis of dietary treatments decreased the price per kilogram of feed (1.49, 1.46, 1.44, 1.41 reais, respectively) as replaced by 0, 10, 20 and 30% levels crude protein soybean meal by sunflower meal. The FG30 treatment compared with other treatments was better, it showed better Average Cost Index (ACI) and Economic Efficiency Index (EEI). The egg production was not influenced with the temperature increase over the weeks, obtaining higher production values between the 39th and 42nd weeks of age, which is due to genetic effects of Isa label. In the evaluation of the surface temperature by infrared thermography, laying hens showed higher average temperature in the neck region (39.35° C), followed by face (38.47° C), feet (37.15° C) and feathered area (31.56° C). Therefore, taking into consideration the viability was observed, the replacement of soybean meal by sunflower meal in balanced diets for broilers Isa label in laying phase can be used / Objetivou-se com este estudo avaliar produção e qualidade dos ovos de poedeiras da linhagem Isa Label alimentadas com diferentes níveis de farelo de girassol, termografia infravermelha e características produtivas de aves em sistema de produção semi-intensivo em condições tropicais. Foram utilizadas 128 aves poedeiras com idade inicial de 28 semanas, durante 16 semanas de avaliação, distribuídas em delineamento inteiramente casualizado, em 16 boxes, com 8 aves por unidade experimental. Os tratamentos constituíram-se em uma ração controle (RCO) e três rações contendo farelo de girassol em substituição ao farelo de soja, com base no teor de proteína bruta, nos níveis de 10, 20 e 30 % (FG10, FG20, FG30), sendo todas as rações formuladas com base nas exigências nutricionais das aves. Durante o período total de avaliação não observou-se diferença (p>0,05) entre os níveis de substituição da proteína bruta do farelo de soja pelo farelo de girassol para o desempenho produtivo e qualidade de ovos das aves. A análise econômica dos tratamentos dietéticos apresentou redução no preço por quilograma de ração (1,49, 1,46, 1,44, 1,41 reais, respectivamente) à medida que substituiu em 0, 10, 20 30% os níveis de proteína bruta do farelo de soja pelo farelo de girassol. O tratamento FG30 em comparação com os demais tratamentos foi melhor, pois apresentou melhor Índice de Custo Médio (ICM) e Índice de Eficiência Econômica (IEE). A produção de ovos não teve influencia do aumento da temperatura ao longo das semanas, obtendo maiores valores de produção entre a 39ª e 42ª semanas de idade o que se deve ao efeito genético da linhagem Isa label. Na avaliação da temperatura superficial das aves através da termografia infravermelha a maior média foi encontrada no pescoço (39,35 °C) seguida da face (38,47 °C) e patas (37,15 °C), onde a área com penas apresentou a menor média (31,56 °C) entre as regiões estudadas. Portanto, levando em consideração a viabilidade econômica das rações, a substituição do farelo de soja pelo farelo de girassol em rações balanceadas para aves Isa label em fase de postura podem ser utilizadas

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-08-20T12:32:16Z No. of bitstreams: 1 ADRIANO DE SOUSA CABRAL - DISSERTAÇÃO (PPGEM) 2017.pdf: 4297640 bytes, checksum: 947cc1f3c800182da45417aaab2b3861 (MD5) / Made available in DSpace on 2018-08-20T12:32:16Z (GMT). No. of bitstreams: 1 ADRIANO DE SOUSA CABRAL - DISSERTAÇÃO (PPGEM) 2017.pdf: 4297640 bytes, checksum: 947cc1f3c800182da45417aaab2b3861 (MD5) Previous issue date: 2017-07-26 / O objetivo desta pesquisa foi analisar se a Termografia pode auxiliar na detecção de falhas em elementos de máquinas, notadamente rolamentos autocompensadores com 2 carreiras de esferas. A motivação surgiu da necessidade de verificar os pontos de falhas existentes nestes elementos mecânicos visando minimizar e/ou eliminar paradas inesperadas que possam comprometer o bom funcionamento dos mesmos e consequentemente das máquinas às quais estão inseridos. A pesquisa é classificada como investigativa, documental, prescritiva, qualitativa e quantitativa. A metodologia utilizada fez uso de bancada de testes composta por elementos mecânicos diversos a citar: motor elétrico controlado por inversor de frequência, amortecedores de vibração (vibra-stop), polias e correias, mancais de rolamentos, carga em eixo, câmera térmica e rolamentos autocompensadores modificados com defeitos nas pistas interna e externa em cenário com condições de controle e não-controle de temperatura ambiente, umidade relativa, rotação do motor, velocidade do ar, temperatura refletida e emissividade. Como resultado, observou-se que houve alteração significativa de temperatura nas pistas interna e externa dos rolamentos com falha do tipo sulco. Por outro lado, não foram percebidas alterações significativas nas pistas interna e externa do rolamento com falha por desgaste por abrasão. Por fim, conclui-se, neste trabalho, que a hipótese inicial foi parcialmente confirmada, isto é, a Termografia pode sim auxiliar a detectar as falhas mecânicas, mas falhas do tipo sulco e não as falhas do tipo desgaste abrasivo. / The aim of this study was to verify if Thermography can help in the diagnosis of failures in machine elements, notably self-aligning bearings with 2 rows of balls. The motivation arose from the need to verify the fault points existing in these mechanical elements to minimize and / or eliminate unexpected stops that could compromise the proper functioning of themselves and consequently of the machines of which they are part of. This study is classified as investigative, documentary, prescriptive, qualitative and quantitative. The methodology made use of test bench composed of several mechanical elements: electric motor controlled by frequency inverter, vibration-stop buffers, pulleys and belts, house bearings, radial load, thermal camera and self-aligning bearings with inner and outer race fault in a scenario with control conditions and non-control of ambient temperature, relative humidity, engine speed, air velocity, reflected temperature and emissivity. It was confirmed that there was a significant temperature change in the inner and outer races of groove-type failure bearings. On the other hand, no significant changes were observed in the inner and outer races of the bearing with abrasion wear failure. Finally, it was concluded in this work that the initial hypothesis was partially confirmed, that is, the Thermography can help to detect mechanical failures in groove type failures but not abrasive wear type failures.

HEINZEN, Eduardo Luiz. Variáveis nutricionais e fisiológicas de ovinos da raça Morada Nova de diferentes classes sexuais submetidos à restrição alimentar. 2016. 50 f. : Dissertação (Mestrado) - Universidade Federal do Ceará, Centro de Ciências, Departamento de Zootecnia, Programa de Pós-Graduação em Zootecnia. Fortaleza-CE, 2016. / Submitted by Eric Santiago (erichhcl@gmail.com) on 2016-08-03T13:37:27Z No. of bitstreams: 1 2016_dis_elheinzen.pdf: 1285825 bytes, checksum: 32955795d549452fb81768336e0dfffc (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-08-03T13:51:24Z (GMT) No. of bitstreams: 1 2016_dis_elheinzen.pdf: 1285825 bytes, checksum: 32955795d549452fb81768336e0dfffc (MD5) / Made available in DSpace on 2016-08-03T13:51:24Z (GMT). No. of bitstreams: 1 2016_dis_elheinzen.pdf: 1285825 bytes, checksum: 32955795d549452fb81768336e0dfffc (MD5) Previous issue date: 2016 / This study was accomplished with the objective of determining the effects of sexual class and feed restriction on nutrient intake, digestibility, purine derivatives, nitrogen balance, feeding behavior and physiological parameters in hair sheep Morada Nova. Thirty-five animals (11 intact males, 12 castrated and 12 females) with an initial average weight of 14.5 ± 0,89kg were used in a completely randomized design in a 3x3 factorial design with three sexual classes (intact males, castrated and females) and three levels of feed restriction (ad libitum, 30 and 60%). Sexual class and feed restriction influenced (P<0.05) the intake of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber corrected for ash and protein (NDFap), total carbohydrates (TC), non-fibrous carbohydrates (NFC), total digestible nutrients (TDN) and metabolied energy (ME) and the balance of nitrogen compounds. The digestibility coefficient of DM, CP and EE were influenced (P<0.05) by feed restriction, however there was no effect (P>0.05) the sexual class on the digestibility coefficients of CP, EE and NFC. There was interaction between sexual class and feed restriction (P<0.05) in digestibility of OM, NDFap and CT. Eating times (ET) and rumination times (RUT) were affected by feed restriction (P<0.05), however they were not affected by sexual class (P>0.05). The urinary volume, excretions of creatinine, allantoin, xanthine and hypoxanthine, absorption of purine derivatives (absPD), total purine derivatives (PD) and microbial protein synthesis (micCP) were not influenced (P>0.05) by sexual class. Urine output, creatinine excretion, xanthine and hypoxanthine were not influenced by feed restriction (P>0.05), however, this factor influenced the excretion of allantoin, uric acid, absPD and PD. Physiological parameters, surficial temperature (ST) on the left of pectoral region and rectal temperature (RT), were not affected by sexual class (P>0.05). Feed restriction and the period of collect of physiological variables influenced (P<0.05) ST the left side, chest and RT. There was interaction (P<0.05) between sexual class and feed restriction ST to the right side. Intake and digestibility of nutrients are influenced by more severe dietary restrictions. Sexual class does not influence the excretion of purine derivatives and microbial protein synthesis. Feed restriction reduces heat losses by body surface of lambs. / Este estudo foi realizado com o objetivo de determinar os efeitos da classe sexual e restrição alimentar sobre o consumo de nutrientes, digestibilidade, derivados de purina, balanço de nitrogênio, comportamento ingestivo e parâmetros fisiológicos de cordeiros da raça Morada Nova. Trinta e cinco animais (11 machos inteiros, 12 castrados e 12 fêmeas), com peso médio inicial de 14,5 ± 0,89kg, foram usados em delineamento inteiramente casualizado, em esquema fatorial 3x3, sendo três classes sexuais (machos inteiros, castrados e fêmeas) e três níveis de restrição alimentar (ad libitum, 30 e 60%). A classe sexual e a restrição alimentar influenciaram (P<0,05) o consumo de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro corrigida para cinzas e proteína (FDNcp), carboidratos totais (CT), carboidratos não fibrosos (CNF), nutrientes digestíveis totais (NDT) e de energia metabolizável (EM) e o balanço dos compostos nitrogenados. O coeficiente de digestibilidade da MS, PB e EE foram influenciados (P<0,05) pela restrição alimentar, no entanto, não houve efeito (P>0,05) da classe sexual sobre os coeficientes de digestibilidade da PB, EE e CNF. Houve interação entre a classe sexual e a restrição alimentar (P<0,05) na digestibilidade da MO, FDNcp e CT. Os tempos de alimentação (TAL) e ruminação (TRU) foram influenciados pela restrição alimentar (P<0,05), no entanto, não foram influenciados pela classe sexual (P>0,05). O volume urinário, excreções de creatinina, alantoína, xantina e hipoxantina, absorção de derivados de purina (absDP), derivados de purinas totais (DP) e síntese de proteína microbiana (PBmic) não foram influenciados (P>0,05) pela classe sexual. Volume urinário, excreções de creatinina, xantina e hipoxantina não foram influenciados pela restrição alimentar (P>0,05), no entanto, este fator influenciou as excreções de alantoína, ácido úrico, absDP e DP. Os parâmetros fisiológicos temperatura superficial (TS) do lado esquerdo, região peitoral e temperatura retal (TR) não foram influenciados pela classe sexual (P>0,05). A restrição alimentar e o período de coleta das variáveis fisiológicas influenciaram (P<0,05) a TS do lado esquerdo, peito e TR. Houve interação (P<0,05) entre classe sexual e restrição alimentar para TS do lado direito. Consumo e digestibilidade de nutrientes são influenciados por restrições alimentares mais severas. Classe sexual não influencia a excreção de derivados de purina e síntese de proteína microbiana. A restrição alimentar diminui as perdas de calor pela superfície corporal de cordeiros.

L’allégement des véhicules est une préoccupation majeure de l’industrie automobile, puisque cela permet de réduire les émissions des gaz à effet de serre, ce qui entraînerait une réduction des impacts de ceux-ci sur l’environnement à l’échelle mondiale. Cette volonté d’allégement des véhicules tout en restant accessible en termes de coûts, a conduit au remplacement des matériaux métalliques par des composites à matrices thermoplastiques pour de nombreuses applications. Le compromis entre la tenue thermomécanique et le coût massique du matériau amène à sélectionner des matrices polyamides renforcées par des fibres de verre courtes, et mises en forme par injection. Cependant, les outils prédictifs du comportement et les critères robustes pour la caractérisation des propriétés en fatigue, manquent encore. Ils sont pourtant indispensables pour la conception de pièces structurelles dans l’industrie automobile. La caractérisation en fatigue des polyamides renforcés de fibres de verre courtes présente de nombreuses difficultés, liées au comportement fortement non linéaire de la matrice dans les conditions de service visées (température et humidité), à la nature composite de ces matériaux, à l’influence du procédé de fabrication (orientation des fibres) et au caractère fortement dissipatif de la matrice thermoplastique (augmentations de température non négligeables lors des chargements cycliques). Un enjeu majeur est de comprendre les liens entre la microstructure, le chargement thermo-(hygro)-mécanique et les propriétés de fatigue (sites d’initiation, scénarios d’évolution, critère de rupture). Le premier objectif de cette thèse est de proposer des protocoles d’analyse permettant de caractériser l’influence de chaque paramètre sur le comportement en fatigue. Par ailleurs, la complexité des pièces industrielles en termes de géométrie et d’orientation des fibres soulève la question de la pertinence des éprouvettes classiques. Le second objectif principal de cette thèse est donc de concevoir des éprouvettes représentatives en terme d’orientation des fibres et d’accidents géométriques des pièces industrielles (appelées éprouvettes de structure) et de valider pour ces cas complexes, les démarches et critères proposés. Pour répondre à ces objectifs, nous souhaitons proposer un protocole basé sur des mesures d’auto-échauffement, qui donnerait accès d’une part aux champs d’énergie dissipée pour les cas hétérogènes investigués et qui offrirait, d’autre part, une opportunité de caractérisation rapide des propriétés en fatigue au travers de critères énergétiques / Vehicle weight reduction is a major issue in the automotive industry, because this contributes to reducing global warming emissions, resulting in a reduction of negative environmental impacts at the worldwide scale. To replace heavy metallic materials conventionally used, short fiber reinforced thermoplastics (SFRT) provide today a major opportunity to obtain lightweight automotive parts at a reasonable cost for several applications. The cost and the thermomechanical properties motivate the choice of polyamide matrix reinforced with glass fibers manufactured by injection molding. However, predictive modeling behavior tools and robust fatigue criteria must be identified. Both are needed for the design of structural pieces in the automotive industry. The fatigue design of SFRT components for structural applications in the automotive industry requires an accurate knowledge of several factors because the material features are complex, these features are related to the strong nonlinear behavior of the matrix under the service conditions (temperature and humidity), the composite nature of the material, the influence of the injection molding (fiber orientation) and the dissipative characteristics of the thermoplastic matrix (significant temperature rise during the cyclic loadings). A major issue is to understand the relations between the microstructure, the thermo-hydro-mechanical loading and the fatigue properties (fatigue initiation sites, evolution scenarios, and failure criterion). The first objective of this thesis is to suggest methods that allow for the characterization of the influence of each parameter on the fatigue behavior. Furthermore, the complexity of the industrial pieces in terms of geometry and fiber orientation challenges the relevancy of the classical samples. The second objective of this thesis is consequently to design more complex samples that intend to be representative in terms of fiber orientation and geometric details found in the industrial pieces (called structural samples) and to validate the methods and the fatigue criteria suggested for these complex cases. To achieve these objectives, a method based on thermal measurements giving access to the dissipation fields for the heterogeneous cases considered is proposed, this method also offers a very high reduction of the characterization duration of the fatigue properties through energetic criteria

Durant ces dernières décennies les matériaux composites organiques ont subi un très grand essor dans le domaine des structures aéronautiques. Leur principal avantage est d’alléger les structures tout en gardant de bonnes propriétés mécaniques. De plus, leur microstructure leur permet d’avoir un caractère multi-fonctionnel, ce qui facilite leur intégration pour remplacer les technologies existantes. Dans l’industrie aéronautique, il existe un besoin croissant de grande quantité de petite et moyenne pièces (clips, éléments de jonctions). Cependant, il est aujourd’hui difficile de fabriquer en série des pièces ayant des formes tridimensionnelles complexes par des procédés conventionnels (autoclave). Ainsi, l’orientation envisagée est d’utiliser les procédés de la « famille » automobile pour des applications aéronautiques « semi-structurales », comme le moulage par injection de composites thermoplastiques renforcés de fibres courtes. Cette application nécessite une maîtrise et une fiabilisation du procédé ainsi que des propriétés induites. Ceci a été réalisé par l’identification et la quantification des effets des paramètres qui influent significativement sur la microstructure et les propriétés macroscopiques, par un plan d’expériences. De plus, le dimensionnement de telles pièces requiert une modélisation robuste du comportement mécanique pour prédire au mieux leur capacité d’utilisation. Les données sur la microstructure ont permis d’alimenter un modèle micromécanique comportant un critère d’endommagement de l’interface fibre/matrice. Développé sur un code éléments finis industriel, il a permis de prédire les résultats expérimentaux d’une pièce industrielle. / During the last decades, organic composite materials have undergone great development in the field of aeronautical structures. Their main avantage is to reduce the structures weight while maintaining good mechanical properties. In addition, their microstructure allows them to have a multi-fuctional nature, which facilitates their integration to replace existing technologies. In the aviation industry, there is a growing need for large amount of small and medium parts (clips, connecting elements). However, nowadays it is difficult to produce parts with complex by conventional methods dimensional shapes (autoclave). Thus, the considered path is tu use methods of the automotive “family” for “semi-structual” aerospace applications such as injection-moulding of thermoplastic composites reinforced by short fibres. This application requires a mastery and reliability of the process and the induced properties. This was achieved by the identification and quantification of the parameters effects that significantly influence the microstructure and macroscopic properties, by a design of experiments. Moreover, the dimensioning of such parts requires a robust mechanical behabior modelling to predict the best use of their capacity. The data on the microstructure enable to feed a micromechanical model featuring damage criteria of the fiber/matrics interface. Developed on a industrial finite element code, it was used to predict the experimental results of an industrial part.

L'étude réalisée au cours de cette thèse s'intéresse au fluage secondaire de gainages de Zircaloy-4 détendu dans des conditions représentatives d'un Accident de Perte de Réfrigérant Primaire (APRP) dans le circuit primaire d'un réacteur à eau pressurisée. Elle s'intègre dans le cadre du projet ANR PERFROI. Ce travail s'articule autour de trois axes que sont la conception d'essais de fluage à haute température et en pression interne sur des gaines, leur réalisation et exploitation, la modélisation de ces essais et la caractérisation du comportement au fluage secondaire de cet alliage, et l'étude du fluage secondaire d'éprouvettes de Zr-4 pré-oxydées. Le banc d'essai est conçu pour induire un chargement thermique hétérogène le long des éprouvettes tubulaires testées en utilisant un chauffage par induction. Le fluage à haute température des métaux est très dépendant de la température. Ce gradient thermique couplé à une pression interne mène alors à une déformation hétérogène de l'éprouvette dans l'axe du tube. En réalisant plusieurs chargements en pression interne, plusieurs conditions thermo-mécaniques sont appliquées en un seul essai. Les essais sont instrumentés de manière à mesurer les distributions cinématique et thermique dans une région de 20 mm située entre les spires de l'inducteur. Deux méthodes d'analyse d'images numériques sont adaptées dans ce but et ont été validées par des essais dédiés. Les essais sont modélisés sous le logiciel commercial ABAQUS6.11-2. Un recalage d'une loi de fluage secondaire est réalisé, par des calculs éléments finis intégrés dans un solveur de Gauss-Newton. Cette démarche est validée avec un essai virtuel puis appliquée à 9 essais réalisés sur des échantillons de Zr-4 vierge. Les résultats permettent de déterminer à la fois l'influence de la température et du chargement mécanique de manière fine pour la gamme de température et pression souhaitée. Ils mettent en évidence un changement brutal de comportement à une température de 810 °C, correspondant au début de la transition de la phase alpha vers un matériau biphasé. De plus, les exposants de Norton identifiés dans le domaine alpha pour des contraintes inférieures à 25 MPa sont de l'ordre de l'unité, et entre 4 et 5 pour les contraintes supérieures. Ces ordres de grandeurs sont respectivement associés dans la littérature à des mécanismes de fluage par diffusion et dislocation. Au-dessus de 810 °C, les caractéristiques associées dans la littérature à la superplasticité sont mis en évidence : l'exposant de Norton est compris entre 2,5 et 3,5 et l'énergie d'activation est supérieure à 300 kJ/mol. Des essais sont enfin menés sur des éprouvettes seulement pré-hydrurées, puis pré-oxydées et pré-hydrurées. Les mesures réalisées pendant ces essais sont associées à des métallographies pour mettre en évidence l'effet des couches de zircone et de phase alpha enrichie en oxygène sur la déformation de la gaine à 800 °C. / The present work investigates the steady-state creep behavior of Stress Relieved Annealed Zircaloy-4 claddings under thermo-mechanical conditions simulating a Loss-Of-Coolant Accident (LOCA) in a primary loop of Pressurized Water Reactors. It is part of the PERFROI project focusing on the flow blockage within fuel rods bundle and its potential impact on the cool ability of a nuclear core reactor. The present work includes three main elements that are (a) the design, the performance and the processing of an innovative experiment, (b) the modeling of the tests and the determination of steady-state creep constitutive laws at temperatures ranging from 750 to 850 °C and (c) the preliminary study of the corrosion effect on the Zr-4 claddings creep behavior. An experiment addressing to heterogeneous thermal conditions was designed using an induction heating device. The creep behavior of metals at high temperatures is known to be very sensitive to the temperature. Under an internal pressurization of the cladding this thermal gradient induces its heterogeneous deformation. Using this configuration and three successive internal pressure loadings with a single experiment a lot of thermal mechanical conditions are available. Both thermal and kinematics full field measurements are performed into a 20 mm gauge length located between the induction coils using respectively near infra-red thermography and two dimensional digital image correlation. These two key digital image methods are assessed using dedicated experiments. The tests are modeled using the ABAQUS commercial software. The expected creep behavior law is updated using finite element model calculations included into a Gauss-Newton solver. The method was validated using virtual experiments and then applied to the actual tests. A high consistency between the experiments is obtained and is in agreement with available literature data. Norton exponent and activation energy maps are plotted into the thermal mechanical condition range of interest. These parameters highlight changes of dominant deformation mechanisms in the alpha-phase domain at a 26 MPa von Mises stress and of micro-structure at an 810 °C temperature (at which phase transformation is expected). In the mixed phase domain, the material parameters are similar to those associated in the literature data with super plasticity deformation mechanism. Finally, experiments are performed on pre-oxidized samples at 800 °C. The rupture of the outer zirconia and oxygen enriched alpha layers is observed during the test at a 1.1\% hoop strain.

Ce travail porte sur l'identification de modèles de zones cohésives. Ces modèles, proposés initialement dans les années 60 sont maintenant de intensivement utilisés dans les simulations numériques pour rendre compte de l'initiation et de la propagation de fissures pour différents matériaux et structures.L'identification de ces modèles reste encore aujourd'hui une problématique délicate. Les développements récents de techniques d'imagerie permettent d'accéder à des champs de mesures locales (e.g. déformation et température, …). On se propose dans ce travail d'utiliser la richesse des informations issues de ces techniques d'imagerie pour mettre en place une procédure d'identification qui prenne en compte à la fois le développement de la localisation (effet de structure) mais aussi la nature des différentes irréversibilités mises en jeu (comportement thermo-mécanique). On s'intéresse à des comportements élasto-plastiques endommageables de matériaux ductiles. L'endommagement est associé à un comportement cohésif de l'interface entre les éléments volumiques supposés purement élasto-plastiques.La procédure d'identification comporte deux étapes. La première consiste à caractériser la forme et les paramètres de la loi cohésive sur des essais de traction standard à partir d'une analyse des champs mécaniques localement développés. La seconde étape consiste à vérifier la cohérence thermo-mécanique du modèle identifié en confrontant les mesures calorimétriques déduites des champs de température avec les prévisions du modèle identifié.Cette méthode est appliquée avec succès sur différents matériaux (acier Dual Phase et cuivre). Une attention particulière est portée sur la caractérisation de la longueur caractéristique qui est nécessairement introduite dans l'identification. On montre que cette longueur peut être estimée au regard des différents paramètres introduits dans les traitements d'images.Cette méthode est appliquée sur différents matériaux (acier et cuivre). Une attention particulière est portée sur la caractérisation de la longueur caractéristique qui est nécessairement introduite dans l'identification. On montre que cette longueur peut-être corrélée à l'échelle d'identification des processus d'endommagement sous-jacents. Ainsi les modèles cohésifs identifiés sont fournis au modélisateur avec l'échelle physique à laquelle ils résument l'endommagement volumique du matériau. / This work deals with the identification of cohesive zone models. These models were intially proposed in the 1960s. They are now more and more frequently used in numerical simulations to account for crack initiation and propagation in different materials and structures.The identification of these models still remains a delicate issue. The recent developments in imaging techniques now allow reaching local measurement fields (e.g. strain, temperature,…). We propose here to use the large amount of information given by these techniques to set up an identification procedure accounting for either the localization development (structural effect) and also the character of the different irreversibility sources encountered (thermo-mechanical behavior). We study damageable elasto-plastic ductile materials. Damage is associated to a cohesive behavior of the interface between volumic elements supposed to remain purely elasto-plastic.The identification procedure involves two steps. The first one consists in characterizing the shape and the parameters of the cohesive zone on tensile tests by analyzing the mechanical fields locally developed. The second one consists in checking the thermo-mechanical consistency of the identified model by confronting the calorimetric measurements deduced from temperature fields with the previsions of the identified model.This method is applied on different materials (Dual Phase steel and copper). A specific caution is conferred to the characterization of the characteristic length necessarily introduced by the identification. It is shown that this length can be estimated regarding the different parameters introduced in the image processing.

Cette thèse porte sur le diagnostic de peintures murales masquées par une couche de chaux ou de peintures avec des repeints.Trois méthodes originales sont présentées et le principe validé expérimentalement.D’abord une nouvelle méthode d’excitation de couches profondes par le rayonnement infrarouge lointain λ>20 μm, qui présente une meilleure efficacité par rapport à la méthode classique d’excitation par conduction thermique. Le fait de filtrer les courtes longueurs d’onde élimine l’échauffement en surface du matériau. La semi-transparence de la couche de chaux dans l’infrarouge lointain permet d’éclairer directement les couches de peintures et d’obtenir des thermogrammes révélant les motifs masqués.Nous avons aussi étudié la transmission des couches de peintures dans l’infrarouge lointain par spectrométrie à transformée de Fourier. Les peintures présentent vers 30 μm dans l’infrarouge lointain des zones d’absorption caractéristiques des groupements fonctionnels. Aussi la mesure directe de l’emission totale dans l’infrarouge lointain à température ambiante de peintures permet leur identification. Nous avons conçu un système qui pourrait être déplacé sur le terrain.Nous avons enfin introduit une nouvelle approche pour le diagnostic des peintures murales masquées par une couche de chaux basée sur la mesure du temps de vol des photons balistiques rétrodiffusés collectés par une caméra à balayage de fente d’une résolution de 2 ps. / This study deals with the diagnosis of hidden paintings by a layer of lime or another paintings.Three original methods are presented and experimentally validated the principle. First, a new excitation method of the deeper layers based on far infrared radiation λ>20 μm, which has a higher efficiency compared to the conventional method of thermal conduction excitement. The fact that the filter removes short wavelength in the heating surface of the material. The semi-transparent layer of lime in the far infrared can illuminate layers of paint directly and get thermograms revealing hidden patterns.We also studied the transmission of the layers of paint in the far infrared by Fourier transform spectroscopy. The painting present in the far infrared 30> μm areas obsorption witch caracteristic of functional groups. Also the measurement of total emission in the far infrared at room temperature allows their identification.Finally, we introduced a new approach for diagnosing murals hidden by a layer of lime based on measuring the time of flight of photons backscattered ballistic collected by a streak camera with a resolution of 2 ps.

Made available in DSpace on 2016-12-06T17:07:11Z (GMT). No. of bitstreams: 1 dissertacao mestrado Luciane Balbinot.pdf: 3627256 bytes, checksum: a36fd0300702dcd6a0c22c892c0255a9 (MD5) Previous issue date: 2006-11-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Computerized thermography, system with ability to capture the infrared light emissivity of any reflexive surface, is part of the current arsenal of instrumentation in biomechanics. Using this methodology, it is possible to evaluate the physiology of thermical maintenance through its skin surface representation. The aim of this work is to evaluate the thermography as the identification method of myofascial trigger points, been chosen the trapezius muscle as study focus since it is one of most affected body regions concerning myofascial syndrome. This syndrome is highly prevalent and historically sub-diagnosticated as it requires expert professionals to establish its diagnostic, through physical examination. The articipants of this study were gathered as a sample of thirty persons, fifteen men and fifteen woman, ages between twenty three and seventy years (32,5 years in average). The algometry by pressure, highly validated method on previous works, has been used as part of physical examination to confirm the thermography events. The equipment used to collect the thermograms was an infrared camera with digital image processing, with thermical sensitivity for spectral ranges from 7 to 12 micrometers, appropriate for medical diagnostic utilization; the error index for measurement on this equipment is either 2% or 2oC. It has been used a dynamometer, clock type, for the algometry, commercially available for clinical use, which makes possible to evaluate the applied pressure to the focal point. The trigger point identification was based in a pain diagram filled by the own subject using previously validated parameters. The imaging evaluation was done using a descriptive analysis, having been taking in consideration the thermographic event corresponding to the trigger point, the hot spot or a discoid shaped surface, with one or more degrees Celsius hotter if compared to the neighbor reference point. Algometry was used in this work as reference method It was applied descriptive statistics for evaluate sensibility and specificity in trapezius Myofascial Syndrome diagnoses. A totality of 250 trigger points had been founded: 198 (79.20%) identified by algometry and thermography; 41 points (16.40%) by thermography only; 11(4.40%) identified by algometry only. It was concluded that the thermograpy is an appropriated method for Myofascial Syndrome diagnostic on trapezius muscle. / A termografia, sistema com capacidade de captar a emissividade de luz infravermelha de qualquer superfície reflexiva, faz parte do arsenal atual de instrumentação em biomecânica. Com esta metodologia pode-se avaliar a fisiologia da manutenção térmica através de sua representação cutânea. O presente trabalho teve por objetivo avaliar a termografia comptadorizada na identificação de trigger points miofasciais, tendo sido escolhido o músculo trapézio como foco de estudo, por esta ser uma das regiões corporais mais acometidas pela Síndrome Miofascial. Esta síndrome é altamente prevalente na população adulta ativa e, historicamente, sub-diagnosticada por requerer profissional especializado e treinado para estabelecer seu diagnóstico, que é através de exame físico. Os participantes deste estudo compunham uma amostra de trinta sujeitos, quinze homens e 15 mulheres, com idade entre 23 e 70 anos (média de 32,5 anos). A algometria de pressão, método validado amplamente em estudos prévios, foi utilizada como parte do exame físico para confirmação ou não dos eventos da termografia. O equipamento utilizado para coleta dos termogramas foi uma câmara de infravermelho com processamento digital de imagens, com sensibilidade térmica em faixa espectral de 7 a 12 micrômetros, adequada à sua aplicação no diagnóstico médico; o índice de incerteza de medição deste equipamento é de 2% ou 2ºC. Para a algometria, utilizou-se um dinamômetro tipo relógio, disponível comercialmente para uso clínico, que permitiu avaliar a pressão aplicada aos pontos de interesse. A identificação dos trigger points foi baseada em diagrama de dor preenchido pelo próprio sujeito e utilizando-se parâmetros previamente validados em publicações cientificas. A avaliação das imagens foi realizada através de análise descritiva, valorizando-se o evento termográfico correspondente ao trigger point, que é um hot spot ou, área em formato discóide, com hipertermia de um ou mais graus Celsius em relação a um ponto de referência circunvizinho. A algometria foi usada como método de referência neste estudo. Utilizou-se análise estatística descritiva dos dados para avaliar a sensibilidade e a especificidade da termografia no diagnóstico de Síndrome Miofascial de músculo trapézio. Foram identificados um total de 250 trigger points; destes, 198 (79,20%) foram identificados pela algometria e termografia simultaneamente; 41 pontos (16,40%) identificados apenas pela termografia e 11 pontos (4,40%) identificados apenas pela algometria. Concluiu-se que a termografia é eficaz na identificação de trigger points miofasciais de músculo trapézio.

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-04-12T17:33:48Z No. of bitstreams: 1 PAULO VICTOR DA SILVA OLINDA – DISSERTAÇÃO (PPGEM) 2018.pdf: 4406932 bytes, checksum: 3015875e87b33898358c6dc22f3c9e3a (MD5) / Made available in DSpace on 2018-04-12T17:33:48Z (GMT). No. of bitstreams: 1 PAULO VICTOR DA SILVA OLINDA – DISSERTAÇÃO (PPGEM) 2018.pdf: 4406932 bytes, checksum: 3015875e87b33898358c6dc22f3c9e3a (MD5) Previous issue date: 2018-02-21 / Capes / O objetivo deste trabalho foi realizar um estudo termográfico visando constatar falha de montagem por desalinhamento em acoplamento flexível do tipo garra, modelo GR 50. A metodologia da pesquisa pode ser caracterizada como do tipo aplicada, quantitativa, explicativa, bibliográfica e experimental. Para tanto, montou-se uma bancada experimental contendo um motor trifásico, eixos, rolamentos e o acoplamento flexível, sem a presença de cargas, destinado a solidarizar dois eixos contendo desalinhamentos entre eles de 0,5; 0,74 e 1,18 mm. Como resultado dos testes efetuados, foi possível perceber que a temperatura do acoplamento aumenta à mesma proporção dos desalinhamentos inseridos, ou seja, quanto maior o desalinhamento, maior a temperatura registrada. Este fato é melhor observado nos primeiros 20 minutos dos testes. Diante destes resultados é possível afirmar que a Termografia pode ser utilizada como técnica de detecção de falhas de montagem por desalinhamento nos primeiros minutos de funcionamento do sistema. / The aim of this work is to perform a thermographic study aiming to verify assembly failure by mounting in flexible claw type coupling, model GR 50. A research methodology can be characterized as applied, quantitative, explanatory, bibliographic and experimental type. For this, an experimental bench was built, containing a three-phase motor, shafts, bearings and the flexible coupling, without a load presence, to join two shafts with misalignments between them; 0.5, 0.74 and 1.18 mm. As a result of the tests performed, it was possible to notice that the temperature of the coupling increases the same proportion of the misalignments inserted, that is, the greater the misalignment, the higher the temperature recorded. This fact is best observed in the first 20 minutes of the tests. In view of these results, it is possible to affirm that the thermography can be used as a technique for detecting mounting faults by misalignment in the first minutes of the system operation.