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.

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.

nÃo hà / Este estudo foi realizado com o objetivo de determinar os efeitos da classe sexual e restriÃÃo alimentar sobre o consumo de nutrientes, digestibilidade, derivados de purina, balanÃo de nitrogÃnio, comportamento ingestivo e parÃmetros fisiolÃgicos de cordeiros da raÃa Morada Nova. Trinta e cinco animais (11 machos inteiros, 12 castrados e 12 fÃmeas), com peso mÃdio inicial de 14,5  0,89kg, foram usados em delineamento inteiramente casualizado, em esquema fatorial 3x3, sendo trÃs classes sexuais (machos inteiros, castrados e fÃmeas) e trÃs nÃveis de restriÃÃo alimentar (ad libitum, 30 e 60%). A classe sexual e a restriÃÃo alimentar influenciaram (P<0,05) o consumo de matÃria seca (MS), matÃria orgÃnica (MO), proteÃna bruta (PB), extrato etÃreo (EE), fibra em detergente neutro corrigida para cinzas e proteÃna (FDNcp), carboidratos totais (CT), carboidratos nÃo fibrosos (CNF), nutrientes digestÃveis totais (NDT) e de energia metabolizÃvel (EM) e o balanÃo dos compostos nitrogenados. O coeficiente de digestibilidade da MS, PB e EE foram influenciados (P<0,05) pela restriÃÃo alimentar, no entanto, nÃo houve efeito (P>0,05) da classe sexual sobre os coeficientes de digestibilidade da PB, EE e CNF. Houve interaÃÃo entre a classe sexual e a restriÃÃo alimentar (P<0,05) na digestibilidade da MO, FDNcp e CT. Os tempos de alimentaÃÃo (TAL) e ruminaÃÃo (TRU) foram influenciados pela restriÃÃo alimentar (P<0,05), no entanto, nÃo foram influenciados pela classe sexual (P>0,05). O volume urinÃrio, excreÃÃes de creatinina, alantoÃna, xantina e hipoxantina, absorÃÃo de derivados de purina (absDP), derivados de purinas totais (DP) e sÃntese de proteÃna microbiana (PBmic) nÃo foram influenciados (P>0,05) pela classe sexual. Volume urinÃrio, excreÃÃes de creatinina, xantina e hipoxantina nÃo foram influenciados pela restriÃÃo alimentar (P>0,05), no entanto, este fator influenciou as excreÃÃes de alantoÃna, Ãcido Ãrico, absDP e DP. Os parÃmetros fisiolÃgicos temperatura superficial (TS) do lado esquerdo, regiÃo peitoral e temperatura retal (TR) nÃo foram influenciados pela classe sexual (P>0,05). A restriÃÃo alimentar e o perÃodo de coleta das variÃveis fisiolÃgicas influenciaram (P<0,05) a TS do lado esquerdo, peito e TR. Houve interaÃÃo (P<0,05) entre classe sexual e restriÃÃo alimentar para TS do lado direito. Consumo e digestibilidade de nutrientes sÃo influenciados por restriÃÃes alimentares mais severas. Classe sexual nÃo influencia a excreÃÃo de derivados de purina e sÃntese de proteÃna microbiana. A restriÃÃo alimentar diminui as perdas de calor pela superfÃcie corporal de cordeiros. / 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.

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-10-14T14:40:26Z No. of bitstreams: 1 Valdemir de Paula e Silva Junior.pdf: 1674024 bytes, checksum: fa219e683d9e8d4feb594943a85825eb (MD5) / Made available in DSpace on 2016-10-14T14:40:26Z (GMT). No. of bitstreams: 1 Valdemir de Paula e Silva Junior.pdf: 1674024 bytes, checksum: fa219e683d9e8d4feb594943a85825eb (MD5) Previous issue date: 2015-02-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Soil water content has an important role for agricultural practices, influencing water movement and storage within the soil. In semiarid regions, knowledge concerning soil water content holds great relevance, mainly due to precipitation’s high spatial-temporal variability and high evapotranspiration indices, bringing about soil water deficit. The aim of this study was to evaluate spatial and temporal stability of soil water content under different cover crop conditions and soil types, in order to identify a representative point for soil water content readings. Additionally, it was evaluated the use of infrared thermography as a tool to estimate non-saturated hydraulic conductivity at a representative watershed, located in Pesqueira, in the semiarid region of Pernambuco. A grid of points for soil water content measurement was monitored, using a capacitive probe. In the first chapter, the soil water content data was evaluated on a hillslope with six measuring points, under natural vegetation and pasture with the same type of soil (Red Yellow Ultisol). According to temporal stability concept, the technique for relative mean differences and standard deviations was applied in order to investigate the point, which is capable of representing the mean temporal behavior of the other measuring points, and the correlation among soil water content points. In the second chapter, temporal variation patterns were analyzed for seventeen soil water content points distributed along the watershed, under two different soil types: Yellow Ulitsol and Regolithic Entisol, and two cover crop conditions, being used the mean relative differences technique and correlation among points in order to validate if the stable point would be the same found for the hill experiment. In the third chapter, published in the Quantitative Infrared Thermography Journal, v.11, 2:2014, p.161-169, infrared thermography technique was used to estimate soil hydraulic conductivity. The study was performed in a laboratory of the Coimbra University, using a slope soil channel and three types of soil and a thermographic video camera to record the images. Estimated hydraulic conductivity data with the infrared thermography technique were correlated to the values obtained with the aid of a constant-head permeameter, by statistical indices and regression analysis. For the fourth chapter, the thermography technique was used under field condition to estimate non-saturated hydraulic conductivity, in the Mimoso watershed, for two soil types: Yellow Ultisol and Fluvic Entisol. Four different hydraulic heads were applied to soil surface, with three replications and seven tests for each soil type under different initial conditions of soil temperature and thermal records using a thermographic camera. Thermal records were correlated to non-saturated soil hydraulic conductivity, which presented high correlations. Water content dynamics technique allowed the identification of a point of stability in the watershed. Thermal records enabled the distinction between the studied soil types, when subjected to different hydraulic heads, being related with the respective non-saturated hydraulic conductivities. It was verified that the thermography is an innovative technique capable of estimating non-saturated hydraulic conductivity, enabling the mapping of soil surface conditions. / A umidade do solo tem grande importância para as atividades agrícolas, influenciando o movimento da água no solo e no seu armazenamento. Em regiões de clima semiárido, o conhecimento da umidade no solo tem grande relevância, principalmente por causa da grande variabilidade espacial e temporal da precipitação e dos altos índices de evapotranspiração, provocando déficit de umidade no solo. O objetivo desse estudo foi avaliar a estabilidade temporal e espacial da umidade do solo sob diferentes condições de cobertura vegetal e tipos de solo a fim de identificar um ponto que representativo para leitura da umidade e a aplicação da termografia por infravermelho, para estimativa da condutividade hidráulica não saturada do solo em uma bacia hidrográfica representativa, localizada na região de Pesqueira, semiárido pernambucano. Foi monitorada uma rede de pontos de medição de umidade, utilizando uma sonda capacitiva. No primeiro capítulo, os dados de umidade foram avaliados em uma encosta com seis pontos de monitoramento, com cobertura de vegetação natural e pastagem paro o mesmo tipo de solo um Argissolo Vermelho Amarelo. De acordo com o conceito de estabilidade temporal, foi aplicada a técnica de diferenças relativas médias e desvios padrão, para investigar o ponto que fosse capaz de representar o comportamento temporal da média dos demais locais de monitoramento, e a correlação entre os pontos de umidade. No segundo capítulo analisaram-se os padrões de variação temporal em dezessete pontos monitorados de umidade distribuídos em escala de bacia, avaliados para dois tipos de solo: Argissolo Amarelo e Neossolo Regolítico, com duas condições de cobertura do solo, sendo aplicada a técnica de diferenças relativas médias e correlação desses pontos, validam-se o ponto estável seria o mesmo encontrado para encosta. No terceiro capítulo, publicado na revista Quantitative Infrared Thermography Journal, v.11, 2:2014, p.161-169, foi utilizada a técnica da termografia de infravermelho para estimativa da condutividade hidráulica do solo. O estudo foi realizado em laboratório na Universidade de Coimbra, utilizando um canal de terra com declividade e três tipos de solo e uma câmera de vídeo termográfica para registros das imagens. Os dados de condutividade hidráulica estimados com a técnica da termografia infravermelha foram correlacionados com os valores medidos obtidos com um permeâmetro de carga constante, por meio de índices estatísticos e análises de regressão. Para o quarto capítulo, a técnica da termografia foi utilizada em campo para estimativa da condutividade hidráulica não saturada, na bacia do Mimoso para dois tipos de solo, Argissolo Amarelo e o Neossolo Flúvico. Foram aplicadas no solo quatro cargas hidráulicas distintas na superfície do solo, com três repetições e sete ensaios em cada solo em diferentes condições iniciais de temperatura do solo e registros térmicos utilizando uma câmera termográfica. Os registros térmicos foram correlacionados com a condutividade hidráulica não saturada do solo onde apresentaram correlações elevadas. A técnica da dinâmica da umidade permitiu identificar um ponto de estabilidade na bacia. Os registros térmicos permitiram distinção no solo estudado, quando submetidos a diferentes cargas hidráulicas, estando correlacionados com as respectivas condutividades hidráulicas não saturadas. Verificou-se que termografia é uma técnica inovadora capaz de estimar características da condutividade hidráulica não saturada, possibilitando mapeamento das condições de superfície do solo.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-05-29T17:22:24Z No. of bitstreams: 2 Tese - Harley Fernandes Rodrigues - 2017.pdf: 14917308 bytes, checksum: 98bd396b4a6b5e7839b6b8ff0fd12102 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-30T10:44:17Z (GMT) No. of bitstreams: 2 Tese - Harley Fernandes Rodrigues - 2017.pdf: 14917308 bytes, checksum: 98bd396b4a6b5e7839b6b8ff0fd12102 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-30T10:44:17Z (GMT). No. of bitstreams: 2 Tese - Harley Fernandes Rodrigues - 2017.pdf: 14917308 bytes, checksum: 98bd396b4a6b5e7839b6b8ff0fd12102 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-04-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / In this thesis a methodology of real-time monitoring of magnetic hyperthermia (HM) in vivo was developed in the murine tumor model Sarcoma 180 using infrared thermography technique. Magnetic nanoparticles (NPM) consisted of Mn ferrites capable of generating heat at low magnetic field amplitude at the 300 kHz frequency within the safety limit determined by Atkinson. It has been shown that the apparent surface temperature value measured with the infrared camera underestimates the real skin temperature value of the mice if the camera objective does not form an angle 0 ° with the normal direction to the animal's skin in the region of interest on the tumor, with the error reaching more than 7.0 ° C (for 60 °). A new theoretical model to estimate the error in the temperature of curved surfaces was developed and proved valid even in the case where the surface temperature diverges significantly from the environment. Preclinical treatment results indicated a complete remission condition in animal that was submitted to 150 min of hyperthermia and other cases with partial remission, suggesting that biological response analyzes need to be done in a long time (> 60 days). Measurements of the intratumoral temperature monitored by three fiber-optic thermometers during the therapeutic procedure of HM with NPM indicated an inhomogeneous heat delivery within the tumor. Additionally, a new methodology for calculating the thermal dose (CEM43) evaluated at the surface, considering each pixel of the thermographic image as a thermometer in the tumor region, indicated that the value T10(t) of the temperature detected in vivo at the surface of the skin over subcutaneous tumors can report, with an error of the order of 5%, the mean intratumoral temperature value during the therapeutic procedure of HM. / Nesta tese foi desenvolvida uma metodologia de monitoramento em tempo real da hipertermia magnética (HM) in vivo no modelo tumoral murino Sarcoma 180 utilizando a técnica de termografia por infravermelho. As nanopartículas magnéticas (NPM) consistiam de ferritas de Mn capazes de gerar calor em baixa amplitude de campo magnético, na frequência de 300 kHz, dentro do limite de segurança determinado por Atkinson. Foi demonstrado que o valor da temperatura superficial aparente medido com a câmera de infravermelho subestima o valor da temperatura real da pele dos camundongos se a objetiva da câmera não formar um ângulo 0° com a direção normal à pele do animal na região de interesse sobre o tumor, podendo o erro chegar a mais do que 7,0 °C (para 60°). Um novo modelo teórico para estimar o erro na temperatura de superfícies curvas foi desenvolvido e se mostrou válido inclusive para o caso em que a temperatura superficial diverge significativamente da ambiente. Resultados pré-clínicos do tratamento indicaram uma situação de remissão completa em animal que passou por 150 min de hipertermia e outros casos com remissão parcial, sugerindo que análises de resposta biológica precisam ser feitas em longo tempo (> 60 dias). Medidas da temperatura intratumoral monitorada por três termômetros de fibra-óptica durante o procedimento terapêutico de HM com NPM indicaram uma entrega de calor não homogênea dentro do tumor. Adicionalmente, uma nova metodologia para o cálculo da dose térmica (CEM43) avaliada na superfície, considerando cada pixel da imagem termográfica como um termômetro na região do tumor, indicou que o valor de T10(t) da temperatura detectada in vivo na superfície da pele sobre tumores subcutâneos pode informar, com um erro da ordem de 5%, o valor da temperatura média intratumoral durante o procedimento terapêutico de HM.

Image based modeling using visual images has undergone major development during the earlier parts of the 21th century. In this thesis a system for automated uncalibrated scene reconstruction using infrared images is implemented and tested. An automated reconstruction system could serve to simplify thermal inspection or as a demonstration tool. Thermal images will in general have lower resolution, less contrast and less high frequency content as compared to visual images. These characteristics of infrared images further complicates feature extraction and matching, key steps in the reconstruction process. In order to remedy the complication preprocessing methods are suggested and tested as well. Infrared modeling will also impose additional demands on the reconstruction as it is of importance to maintain thermal accuracy of the images in the product. Three main results are obtained from this thesis. Firstly, it is possible to obtain camera calibration and pose as well as a sparse point cloud reconstruction from an infrared image sequence using the suggested implementation. Secondly, correlation of thermal measurements from the images used to reconstruct three dimensional coordinates is presented and analyzed. Lastly, from the preprocessing evaluation it is concluded that the tested methods are not suitable. The methods will increase computational cost while improvements in the model are not proportional. / Bildbaserad modellering med visuella bilder har genomgått en stor utveckling under de tidigare delarna av 2000-talet. Givet en sekvens bestående av vanliga tvådimensionella bilder på en scen från olika perspektiv så är målet att rekonstruera en tredimensionell modell. I denna avhandling implementeras och testas ett system för automatiserad okalibrerad scenrekonstruktion från infraröda bilder. Okalibrerad rekonstruktion refererar till det faktum att parametrar för kameran, såsom fokallängd och fokus, är okända och enbart bilder används som indata till systemet. Ett stort användingsområde för värmekameror är inspektion. Temperaturskillnader i en bild kan indikera till exempel dålig isolering eller hög friktion. Om ett automatiserat system kan skapa en tredimensionell modell av en scen så kan det bidra till att förenkla inspektion samt till att ge en bättre överblick. Värmebilder kommer generellt att ha lägre upplösning, mindre kontrast och mindre högfrekvensinnehåll jämfört med visuella bilder. Dessa egenskaper hos infraröda bilder komplicerar extraktion och matchning av punkter i bilderna vilket är viktiga steg i rekonstruktionen. För att åtgärda komplikationen förbehandlas bilderna innan rekonstruktionen, ett urval av metoder för förbehandling har testats. Rekonstruktion med värmebilder kommer också att ställa ytterligare krav på rekonstruktionen, detta eftersom det är viktigt att bibehålla termisk noggrannhet från bilderna i modellen. Tre huvudresultat erhålls från denna avhandling. För det första är det möjligt att beräkna kamerakalibrering och position såväl som en gles rekonstruktion från en infraröd bildsekvens, detta med implementationen som föreslås i denna avhandling. För det andra presenteras och analyseras korrelationen för temperaturmätningar i bilderna som används för rekonstruktionen. Slutligen så visar den testade förbehandlingen inte en förbättring av rekonstruktionen som är propotionerlig med den ökade beräkningskomplexiteten.

Résumé : Cette étude a pour objectif de mieux comprendre les mécanismes précurseurs de l'amorçage de fissures dans le cas de métaux ductiles monophasés, comme le cuivre pur, sollicités à des amplitudes de contrainte inférieures à la limite de fatigue conventionnelle et jusqu'à des nombres de cycles atteignant le domaine de la fatigue gigacyclique (Very High Cycle Fatigue, VHCF). Les essais ont été réalisés sur une machine de fatigue ultrasonique à une fréquence de sollicitation de 20 kHz. Les mécanismes précurseurs de l'amorçage des fissures se manifestent (1) sous forme de bandes de glissement qui apparaissent sur la surface de l'éprouvette et (2) par un auto-échauffement du matériau dû à la dissipation intrinsèque. Les cartographies de température de la surface des éprouvettes nous ont permis d'estimer des dissipations d'énergie moyennes et de caractériser leur évolution avec le nombre de cycles et l'amplitude de contraintes. En parallèle, l'évolution du relief de la surface, initialement lisse et sans contrainte résiduelle, a été analysée à partir d'observations en microcopie optique, électronique à balayage et à force atomique. Nous avons établi que l'amplitude de contrainte nécessaire pour faire apparaître les premières bandes décroit en fonction du nombre de cycles. Des analyses EBSD, couplées à des calculs éléments finis intégrant l'anisotropie élastique des grains, ont révélé le rôle clé (1) des joints de macles et (2) du glissement dévié dans l'amorçage de bandes de glissement intenses.Mots clés : Fatigue gigacyclique, Bandes de glissement, Microplasticité cyclique, Dissipation, Anisotropie élastique, Simulation multicristalline, Thermographique infrarouge. / Abstract : This work aims to better understanding mechanisms leading to crack initiation in ductile single phase metals such as pure copper, loaded stress amplitudes lower than the conventional fatigue threshold and after about 109 cycles, the so-called Very High Cycle Fatigue regime. Tests were conducted using an ultrasonic technique at loafing frequency of 20 kHz. The mechanisms leading to crack initiation express (1) via slip bands at the specimen surface and (2) via self-heating due to intrinsic dissipation. Thermal maps were used to estimate the mean dissipation and its change with number of cycles and stress amplitudes. At the same time, the surface relief changes were characterized using optical, scanning electronic and atomic force microscopes. The stress amplitude required to observe the slip bands was found to decrease as a function of number of cycles. EBSD investigations combined with finites elements simulations accounting for elastic anisotropy of copper revealed the key role of (1) twin boundaries and (2) cross slip in slip band initiation.Keywords : Very High Cycle Fatigue, Slip bands, Cyclic microplasticity, Dissipation, Elastic anisotropy, Multicrystals simulation, Infrared thermography.

Ce mémoire aborde la question de la production d’observables intrinsèques au comportement thermomécanique des matériaux pour mieux en formuler les lois d’états. Ces observables sont les sources de chaleur thermomécaniques, activées par sollicitation mécanique. Ces sources peuvent être reconstruites dans l’espace et le temps par inversion de mesures de champs de température obtenus par thermographie IR. Nous présentons essentiellement deux méthodes développées lors de ce travail de thèse qui reposent sur des approches spectrales réduites (dont la décomposition sur Modes de Branche) et des inversions séquentielles (méthode de Beck) ou itératives (Gradient Conjugué). Concernant cette dernière, nous proposons d’y adjoindre une régularisation efficace en s’inspirant de techniques de filtrage par TSVD. S’agissant de matériaux sujets aux instabilités plastiques (PolyEthylène Haute Densité) pour lesquels les vitesses locales peuvent être non négligeables, l’inversion des mesures en température nécessite que l’on considère un opérateur d’advection-diffusion, qui impose alors l’apport d’une connaissance supplémentaire : le champ de vitesses locales. Celui-ci est mesuré par corrélation d’images 3D et nous détaillons le travail expérimental mené ainsi que les résultats obtenus sur des essais de traction pilotés par vidéo-extensométrie. Nous montrons que pour des essais quasi-statiques à vitesses relativement élevées, les effets d’advection sont généralement négligeables. Nous montrons également en quoi la richesse des informations thermomécaniques (Sources) et cinématiques (Taux de déformation, vitesses) permet de mieux comprendre la dynamique de l’instabilité plastique. Enfin nous critiquons les résultats obtenus sur la reconstruction de source par confrontation des deux algorithmes développés et par une analyse physique des phénomènes observés / This work concerns the way intrinsic observables can be produced, which are related to the thermomechanical behavior of materials and necessary for better formulation of state laws. These observables are Thermomechanical Heat Sources (THS) which are activated through mechanical excitation. These sources can be reconstructed both in space and time by the inversion of measured temperature fields obtained through IR thermography. We develop two main methods in this work which rely on spectral reduced approaches (one of them being the decomposition on Branch Modes) and both on a sequential inversion (Beck’s method) and an iterative one (Conjugated Gradient). Regarding the latter, we suggest to combine the standard approach with an efficient regularization method which comes from the filtering techniques based on TSVD. As we are concerned with materials which can be subjected to plastic instabilities (High Density PolyEthylene) for which local velocities of matter displacement can be non negligible, the inversion of the measurements must be performed with the advection-diffusion operator of heat transfer. It is then necessary to obtained additional knowledge: the velocity field. This one is measured by 3D Digital Image Correlation and we detail the experimental work we have carried out, which are based on tensile tests monitored with video-extensometry. We show that for quasi-static tests at relatively high strain rates, the advective effects are generally negligible. We also show the richness of the information brought by this dual thermomechanical (heat sources) and kinematical (strain-rates, velocities) information. It allows for a better understanding of the plastic instability (necking) dynamics. Lastly, we criticize the obtained results on THS reconstruction by the confrontation between the two algorithms and by a physical analysis of the observed phenomena

Ces travaux traitent de l'utilisation de la thermographie infrarouge dans le cadre du contrôle non destructif des ouvrages de génie civil.Une première partie, traite de l’étude des paramètres influençant la mesure in situ, de la capacité de la technique à détecter la variation de propriétés intrinsèques au matériau, et de la détection de délaminations. Les résultats présentés sont issus de mesures expérimentales appuyées par une approche numérique aux éléments finis. Dans un premier temps, une étude sur la capacité de la thermographie infrarouge à détecter des variations de porosité ou de teneur en eau a été réalisée. Dans un second temps, des travaux sont menés sur la détermination des seuils de détection des délaminations en fonction des conditions d’exposition. Ils ont montré un seuil de détection correspondant à un rapport de 2, entre l’extension latérale du défaut et sa profondeur, pour un ensoleillement direct, et à un rapport de 3,3 pour un ouvrage soumis uniquement aux variations de température de l’air. La réalisation d’un suivi temporel combiné à l’étude de l’évolution des gradients temporels de température permet d’améliorer ces seuils de détection. Enfin, une étude originale sur le pontage présent au niveau des délaminations, a montré la prédominance de l’influence de celui‐ci sur la profondeur des délaminations.Une deuxième partie porte sur les travaux réalisés dans le cadre du projet ANR‐SENSO. Ils traitent de la combinaison des résultats issus de différentes techniques de CND dans le cadre plus large de l'amélioration des diagnostics pour la gestion du patrimoine. / This thesis focuses on the use of infrared thermography as a tool for non destructive testing ofbuildings. Mainly, the application is on civil engineering projects.The first part includes identifying the parameters that can affect this in situ technique. Thisparticularly deals with the infrared thermography capacity to detect intrinsic property variations, anddelamination detection. Combination of experiments on concrete slabs and numerical simulationsare used. In a first step, a study on the capacity of thermography to detect porosity and watercontent variation was conducted. In a second step a study on the thresholds for detectingdelaminations based on exposure conditions is carried out. As an outcome, the threshold that hasbeen detected corresponds to a ratio of 2 between the lateral extension of the defect and its depthto direct sunlight; while a ratio of 3,3 if it is exposed to air temperature variations. This studysuggests that a time monitoring combined with the study of the evolution of temporal temperaturegradients can improve the detection limits. Finally, an original study showed the predominance ofthe influence of bridging on the depth of delamination.The second part tackles the works carried out during the ANR project SENSO. Results fromdifferent non destructive tools were coupled for the purpose of improving diagnosis in the assetmanagement.