Past studies on sands have shown that the shear strength measured in plane strain tests was higher than that measured in triaxial tests. It was observed that this difference changed with the friction angle &amp / #966 / cv at constant volume related to the mineralogical composition. In order to investigate the difference in strength measured in the wedge shear test, which approaches the plane strain condition, in the triaxial test, and in the shear box test, Anatolian sands were obtained from different locations in Turkey. Mineralogical analyses, identification tests, wedge shear tests (cylindrical wedge shear tests (cylwests) and prismatic wedge shear tests (priswests)), triaxial tests, and shear box tests were performed on these samples. In all shear tests, the shear strength measured was found to increase with the inclination &amp / #948 / of the shear plane to the bedding planes. Thus, cylwests (&amp / #948 / = 60o) iii yielded higher values of internal friction &amp / #966 / by about 3.6o than priswests (&amp / #948 / = 30o) under normal stresses between 17 kPa and 59 kPa. Values of &amp / #966 / measured in cylwests were about 1.08 times those measured in triaxial tests (&amp / #948 / &amp / #8776 / 65o), a figure close to the corresponding ratio of 1.13 found by past researchers between actual plane strain and triaxial test results. There was some indication that the difference between cylwest and triaxial test results increased with the &amp / #966 / cv value of the samples. With the smaller &amp / #948 / values (30o and 40o), priswests yielded nearly the same &amp / #966 / values as those obtained in triaxial tests under normal stresses between 20 kPa and 356 kPa. Shear box tests (&amp / #948 / =0o) yielded lower values of &amp / #966 / than cylwests (by about 7.9o), priswests (by about 4.4o), and triaxial tests (by about 4.2o) under normal stresses between 17 kPa and 48 kPa. It was shown that the shear strength measured in shear box tests showed an increase when &amp / #948 / was increased from 30o to 60o / this increase (about 4.2o) was of the order of the difference (about 3.6o) between priswest (&amp / #948 / = 30o) and cylwest (&amp / #948 / = 60o) results mentioned earlier. Shear box specimens with &amp / #948 / = 60o, prepared from the same batch of any sample as the corresponding cylwests, yielded &amp / #966 / values very close to those obtained in cylwests.

[pt] Neste presente trabalho buscou-se avaliar a características de resistência ao cisalhamento e da relação sucção-umidade de um solo tropical maduro encontrado no campo experimental II da PUC-Rio, localizado na cidade do Rio de Janeiro. Para a determinação da resistência ao cisalhamento deste solo, foram executados ensaios de cisalhamento direto em amostras submersas utilizando equipamento convencional e ensaios de cisalhamento direto com sucção controlada em amostras com umidade natural. Os ensaios de cisalhamento direto com sucção controlada foram executados utilizando o equipamento desenvolvido na PUC-Rio por de Campos (1988), na qual utiliza a técnica de translação de eixos desenvolvida por Hilf (1956) para o controle da sucção aplicada. Para a determinação da relação sucção-umidade, foram realizados ensaios para a medição da sucção utilizando-se o método do papel filtro. Através dos resultados deste ensaio foi possível a determinação da curva característica do solo em estudo. Foram realizados também ensaios de compressão diametral a fim de se estabelecer uma relação entre a resistência à tração deste solo versus sua sucção. Através da análise dos resultados experimentais, foi possível a determinação da envoltória de resistência ao cisalhamento em 3 dimensões considerando a proposta de Fredlund et al. (1978), na qual se baseia na utilização das variáveis de tensão (tensão normal n - ua) e (ua - uw). / [en] In this present work one searched to evaluate the characteristics of shear strength and the suction-moisture relation of a tropical mature soil found in experimental field II of PUC-Rio, located in the city of Rio de Janeiro. For the determination of the shear strength of this soil, direct shear test in submerged samples using conventional equipment and direct shear tests with controlled suction in samples with natural moisture had been executed. The direct shear tests with controlled suction had been executed using the equipment developed in PUC-Rio for De Campos (1988), in which it uses the technique of translation of axles developed by Hilf (1956) for the control of the applied suction. Tests for the measurement of the suction which uses the filter paper method was carried through for the determination of the suction-moisture relation. Through the results of this test, the determination of the soil-water characteristic curve of this soil was possible. Diametrical compression test had also been carried through in order to establish a relation between the tensile strength of this soil versus its suction. Through the analysis of the experimental results, the determination of the shear strength envelope in tri-dimensions was possible considering the proposal of Fredlund et al. (1978), on which it bases on the use of the variables of tension (normal tension n - ua) and (ua - uw).

Les alliages à mémoire de forme Nickel Titane sont des matériaux aux propriétés remarquablesdues à une transformation martensitique réversible et sont largement utiliséspar l’industrie biomédicale et dans des dispositifs de type actionneurs. La première partiede cette étude porte sur une analyse de leur comportement thermomécanique basée surla réalisation de mesures de champs cinématiques (par corrélation d’images visibles) etthermiques (par caméra infrarouge). Une part importante du travail présenté concernel’amélioration des calculs de sources de chaleur à partir des champs de température. Pource faire, les capacités et conductivités thermiques des phases austénitique et martensitiqueont été estimées par différentes méthodes expérimentales. Ensuite, la méthode de calcul desource a été validée sur des données virtuelles obtenues numériquement et sur des donnéesexpérimentales obtenues lors d’une transformation martensitique induite par un refroidissementnaturel. Cette première partie se conclut par l’application des développements àdes mesures réalisées lors d’un essai de cisaillement. La seconde partie est une contributionà la réalisation de matériaux architecturés constitués d’empilement de tubes de NiTi liésentre eux ; notre étude concerne la réalisation et la caractérisation de liaisons de tubes deNiTi par soudage résistif. / NiTi shape memory alloys have amazing properties due to a reversible martensitictransformation and are widely used by biomedical industries and as actuators. The firstpart of this study deals is a thermomechanical analysis of the material, based on kinematical(with digital image correlation) and thermal (with infrared camera) field measurements.An important part of this work deals with the improvement of the heat sources estimationfrom thermal fields. For this, thermal heat capacities and conductivities of austeniteand martensite were estimated with several experimental methods. Then, the heat sourceestimation method was validated from virtual data obtained numerically and from experimentaldata obtained during a martensitic transformation induced by natural cooling.This first part is concluded with the use of this technique to study shear tests. The secondpart of this study is a contribution to the realization of architectured materials composedof linked stacked tubes. Our study deals with the realization and the characterization ofthe NiTi link, realized by resistance welding.

Le collage par adhérence moléculaire est un collage basé sur la mise en contact de deux surfaces sans l'utilisation de colle ou matériaux additionnels. Ce procédé de collage est utilisé dans de nombreuses applications, notamment dans les domaines de l'optique terrestre et spatiale. Bien qu'un prototype ait déjà passé avec succès l'environnement spatial - où les contraintes d'utilisations sont différentes de celles rencontrées sur Terre - la spatialisation de cette technologie nécessite une caractérisation plus fine du procédé ainsi qu'une amélioration de la tenue mécanique des interfaces adhérées afin de valider les normes de l'Agence spatiale Européenne. Pour répondre à cette problématique de spatialisation de la technologie, des essais mécaniques ainsi que des analyses chimiques ont été réalisés dans le but d'étudier l'influence de certains paramètres du procédé ) sur la tenue mécanique et l'énergie de collage. Ces essais ont également été réalisés afin de comparer les deux matériaux étudiés : le verre de silice et le Zérodur vis-à-vis de l'adhésion. A l'issue de ces essais, les paramètres à appliquer permettant de doubler la tenue mécanique des interfaces adhérées ont été déterminés. Parallèlement, une loi phénoménologique reliant l'énergie de collage aux précédents paramètres du procédé a été développée ainsi qu'un modèle macroscopique visant à décrire l'intensité d'adhésion. Ces deux modèles une fois couplés permettent de modéliser le comportement normal de l'interface en fonction des paramètres du procédé. Enfin, ces deux lois sont implémentées dans un code éléments finis afin de simuler la propagation de la fissure lors de l'essai de clivage au coin. / Direct bonding consists in joining two surfaces without the use of any adhesive or additional material. This process is used in several applications, particularly in terrestrial and spatial optics. Although a prototype passed with success spatial environment - where constraints involved are very different from those encountered on Earth - this technology requires a more detailed characterization and an improvement of the mechanical strength of bonded interfaces in order to validate the European Space Agency standards. To address this issue, mechanical tests (double shear tests, cleavage tests and wedge tests) and chemical analysis (wetting tests and XPS spectroscopy) were performed in order to study the influence of some process parameters (roughness, relative air humidity during room temperature bonding, the annealing temperature and time) on the mechanical strength and the bonding energy. These tests compared the two materials used: fused silica glass and Zerodur glass. As a result of these tests, optimal parameters doubling the mechanical strength were also obtained. In the same time, a phenomenological law relating the bonding energy to the previous parameters is developed as well as a macroscopic model to describe the adhesion intensity. Both models when coupled describe the normal behavior of the bonded interface depending on the process parameters. Then, the both laws are implemented in a finite elements model in order to simulate the crack propagation during the wedge test.

Ce travail décrit une étude expérimentale sur des tôles en Ni-Ti à température ambiante en cisaillement plan simple, et pour des vitesses de déformation de 10-4 à 103/s. En quasi-statique (10-4-10-2/s), la mesure optique du champ de déplacement est indispensable à cause du faible déplacement (0.3mm). Des essais à vitesse de déformation intermédiaire (10-1-101/s) ont été réalisés avec la Machine MTS modifiée, capable d'aller à 300mm/s. Une caméra rapide est nécessaire pour suivre ces tests. Enfin, des barres de Hopkinson sont utilisées pour les essais à haute vitesse (102-103/s).Les efforts se sont concentrés sur la méthodologie afin d'explorer les limites expérimentales. Au niveau mécanique, des efforts ont été apportés sur la conception des montages des mors pour combiner des exigences contradictoires. Au niveau mesure, des caméras optiques fonctionnant jusqu'à 5M images/s ont été utilisées. La texture des images, la peinture, la lumière, la taille d'élément et l'incertitude sont analysées. De plus, la caméra infrarouge est utilisée pour confirmer l'observation optique sous faibles vitesses de déformation.Finalement, des essais ont été réalisés pour 7 ordres de grandeurs de la vitesse de déformation, avec identification de la relation contrainte-déformation et observation de l'évolution de la bande de transformation. On observe : (i) Une augmentation de la contrainte avec la vitesse de déformation. (ii) Un champ de déformation non homogène, même en faible vitesse, avec une bande à 10 degrés par rapport à la direction de cisaillement. (iii) Deux bandes séparées à haute vitesse (102/s), ce qui indique que la bande de localisation dépend de la vitesse de chargement. / This work describes an experimental study on a NiTi alloy at the ambient temperature (Pseudoelastic behavior) under the double in-plane shear loading over strain rates from 10-4 to 103/s. Under quasi-static loadings (10-4-10-2/s), the optical full-field measurement is necessary because of the very small displacement (0.3mm). The intermediate loading rates (10-1-101/s) are realized with a modified MTS machine able to load at 300mm/s. Moreover, a high-speed camera is needed to follow such tests. Finally, the Split Hopkinson bars are used to perform tests at impact loading rates (102-103/s).The main effort has been made on the methodological study to explore the experimental possibility. For the mechanical level, the attention has been paid on the design of the clamping system to cope with the contradictory requirements. For the measuring level, different optical cameras with sampling rate till to 5M frames/second are used. The texture, the painting, the lightening, the element size and the uncertainty are analyzed. Furthermore, an infrared camera was used at lower loading rates to confirm the DIC measurement.The tests are continually performed over 7 decades of the strain rate. The nominal stress-strain curves and the detailed observation of the transformation band evolution are measured. The main findings are as follows: (i) Regular stress increase with the strain rate; (ii) an inhomogeneous strain field under in-plane shear condition, even at very low strain rates, with a band at 10 degrees from the shear direction under lower strain rates. (iii) Two separated bands at the strain rate of 102/s, which suggests that the localized transformation bands are rate dependent.

Les ventes des fromages AOP subissent un affaiblissement. L’utilisation de ces fromages sous forme d’ingrédient représente une alternative intéressante à la dégustation et permettrait de maintenir une activité durable aux producteurs de ces fromages. L’objectif de ce travail est d’explorer les potentialités de 4 catégories de fromages à pâte persillée AOP du Massif-Central à être utilisés comme ingrédient à chaud pour répondre à des propriétés telles que « fondant, nappant, filant, gratinant». Les fonctionnalités recherchées pour ce type d’usage ont été prospectées à l’aide de méthodes physico-chimiques et instrumentales classiques mais également à l’aide de méthodes spectrales et sensorielles afin d’enrichir les observations de la macro et microstructure fromagère et de la perception du consommateur. Dans un premier temps, les caractéristiques physicochimiques, rhéologiques et sensorielles à froid et certaines propriétés à chaud ont été décrites pour les 4 catégories de fromages. Ces premiers résultats ont permis de cataloguer les fromages selon des caractéristiques essentiellement liées à l’organisation matricielle des composants tels que les protéines, les matières grasses, les minéraux. L’analyse sensorielle a permis de décrire précisément certaines propriétés à froid qui ne sont pas mises en évidence par d’autres analyses. Les pâtes persillées ont une grande hétérogénéité de pâte due à la présence de« veines » de moisissures. La seconde partie est une étude sur la capacité de la SFS en tant que méthode d’étude de la micro structure, à prédire la diversité de composition de ces fromages. Malgré la forte hétérogénéité des fromages, la SFS permet une « empreinte » identifiable des fromages et prédit certains mais pas la totalité des paramètres physicochimiques. L’évolution de la macro et microstructure de ces fromages au cours du chauffage et du refroidissement a ensuite été étudiée par SFS et par test de compression dynamique. Ces méthodes décrivent bien la fonte de la matière grasse et de la matrice fromagère. Elles sont corrélées entre elles et démontrent une relation entre la structure moléculaire et les propriétés rhéologiques de ces fromages. Une étude comparative des propriétés sensorielles des fromages a été menée à froid et après chauffage. Les attributs décrivent des caractéristiques de texture différentes entre les 2 conditions. Cette démarche a permis de bien différencier les 4 catégories de fromages et de mettre en évidence certains attributs de qualité ou de défaut pour une utilisation à chaud. En conclusion, ces 4 catégories de fromages à pâte persillée ont des potentialités à être utilisées comme ingrédient pour usage à chaud. L’analyse sensorielle a caractérisé les perceptions des consommateurs vis à vis de ces fromages chauffés et ainsi aider à préciser leurs fonctionnalités. Les analyses rhéologiques et spectrales ont apporté des explications liées à ce traitement au niveau de la macro et microstructure de la matrice fromagère. / Sales of PDO cheeses undergo a decline. The use of these cheeses in the form of ingredient represents an interesting alternative to the tasting and would allow to maintain a sustainable business activity to the producers of these cheeses. The objective of this work is to investigate the potentialities of four categories of Blue cheese PDO of the Massif Central as an ingredient to meet their properties during heating such as "melting, stretchability, browning". The functional properties desired for this type of cheese have been investigated by physico-chemical methods and instrumental classics and also by spectral method and sensory evaluations to enrich the observations of the macro and microstructure of the cheese and the consumer perception. First, the physicochemical, rheological, sensory characteristics and certain properties during heating have been reported for four categories of Blue cheese. These initial results allowed us to characterize the cheese studied according to their characteristics essentially which were related to the organization matrix constitutes such as proteins, fats, minerals. The sensory analysis allowed to describe exactly certain properties which are not revealed by theother analyses. Blue-veined cheeses have a great heterogeneity due to the presence of "veins" of mold. The second part is a study on the ability of the SFS method to study the micro structure and to predict the diversity of composition of these cheeses. Despite the high heterogeneity of cheeses, SFS allows an identifiable 'fingerprint' of cheese and predicts some but not the totality of the physicochemical parameters. The evolution of the macro-and microstructure of these cheeses during heating and cooling was then studied by SFS and dynamic shear test. These methods describe well the melting temperature of the fat and the cheese matrix. They are correlated between them and demonstrate a relationship between the molecular structure and the rheological properties of these cheeses. A comparative study of the sensory textural properties of cheeses was carried out in the non- and heated forms. The attributes describe different characteristics of texture between the two conditions. This approach allowed to differentiate well the four categories of cheeses and to highlight on certain attributes of quality or defects to be used in cooking application. In conclusion, these four categories of Blue-veined cheeses have the potential to be used as an ingredient in cooking application. The sensory analysis characterized the perceptions of the consumers in both non- and heated forms and thus helps to specify their features. The rheological and spectral analyses have provided explanations related to this treatment at the level of the macro and microstructure of the cheese matrix.

Esta tesis tiene como objetivo evaluar un método de reforzamiento propuesto en base a la incorporación de fibras de polipropileno con la finalidad de incrementar la resistencia y mejorar las características mecánicas del suelo arcilloso de Palian – Huancayo. La arcilla es un suelo cohesivo constituido por partículas finas, estas características determinan la capacidad de deformación y compresión, además poseen baja resistencia al corte y a cargas. Debido a ello se busca reforzar y mejorar el comportamiento mecánico de la arcilla mediante métodos físicos y químicos. Esta investigación propone la adición fibras de polipropileno como método de reforzamiento para lo cual se analizó el suelo remoldeado con diferentes porcentajes de fibras adicionadas 0.1, 0.2, 0.3, 0.4 y una longitud de fibra de 10 milímetros. Se realizaron ensayos de caracterización física para identificar el suelo natural remoldeado: granulometría por sedimentación, límites de consistencia y gravedad específica de los sólidos. Se sometió el suelo natural remoldeado y las mezclas con diferentes porcentajes de fibras a los siguientes ensayos de caracterización mecánica para determinar las variaciones en el comportamiento: ensayo de compactación estándar, ensayo de corte directo y ensayo de compresión simple. Los valores obtenidos mediante los ensayos realizados demostraron la mejora de las características mecánicas del suelo siendo la mezcla de 0.4% de fibras de polipropileno la que brinda un mejor resultado en comparación con las mezclas de menor proporción. / This thesis aims to evaluate a reinforcement method based on the incorporation of polypropylene fibers to increase the strength and improve the mechanical characteristics of Palian- Huancayo’s clay soil. Clay is a cohesive soil consisting of fine particles, these characteristics determine the capacity of deformation and compression, as well as low resistance to cutting and loads. Therefore, it seeks to strengthen and improve the mechanical behavior of clay through physical and chemical methods. This research proposes the addition of polypropylene fibers as reinforcement method for which the soil under study was analyzed with different percentages of fibers added 0.1, 0.2, 0.3, 0.4 and a fiber length of 10 millimeters. Physical characterization tests were carried out to identify the natural soil: granulometry by sedimentation, limits of consistency and specific gravity of the solids. The natural soil and the mixtures with different percentages of fibers were subjected to the following mechanical characterization tests to determine the variations in behavior: Standard compaction test, unconfined compression test, and shear direct test. The values obtained through the tests demonstrated the improvement of the mechanical characteristics of the soil being the mixture of 0.4% of polypropylene fibers the one that provides a better result compared to the mixtures of a lower proportion. / Tesis

The subject of the submitted work is the experimental and theoretical investigation of composite slabs. The work also deals with creation of numerical models of composite slabs. The design of a new type of steel sheeting for composite slab according to nowadays standards requires full scale laboratory bending tests. An alternative to the bending tests are the small scale shear tests. The small scale shear tests as well as corresponding design methods have already been investigated by many researchers. Therefore several test arrangements and corresponding design methods can be found in literature but none of them is included in standards yet. The submitted thesis describes three of the alternative design methods: Slip- Block Test, Simplified Method and Built-up Bars. The test arrangement is proposed to be usable in all these methods. The small scale shear test have been performed in laboratory in several modifications. The results were used to calculate the bending resistance of the slab by the alternative design methods. The calculated bending resistances were mutually compared, compared with the performed bending tests resistances and the resistances by the methods described in Eurocode: m-k method and partial connection method. A sensitivity studies of the input parameters in alternative design methods are presented as well. The optimal design method for use in practice was searched and recommended based on the performed studies, accuracy and laboriousness of the methods. The shear tests were used also to measure longitudinal shear resistance of the additional shear anchors. The alternative design methods were used to predict bending resistance of the slab using these anchors and the results were compared. The numerical simulation of the composite action of the slab by the finite element methods is modelled in Atena software. The models serves to perform parametrical studies and to better understand of the behaviour of the slab in partial composite action.

The undrained shear strength and preconsolidation pressure are key parameters in describing the characteristics of soft clays. The two parameters both reflect the clay’s structure and state of stress, and hence empirical correlations for undrained shear strength normalized with respect to preconsolidation pressure are widely used to assess soil behavior. The empirical correlations given in the literature are typically dependent on liquid limit, or plasticity index, but some studies have questioned the dependency and proposed correlations constant for consistency limits. Data from geotechnical projects often display a considerable scatter and deviate from established empirical correlations. In this thesis, statistical analyses are performed and evaluated qualitatively on direct simple shear, constant rate of strain and fall cone test data from 146 sampling points with a total of 596 soil samples from Stockholm, Gothenburg and Uppsala. The aim is to investigate the correlation between shear strength and the preconsolidation pressure. The thesis evaluates the normalized shear strength’s dependency on liquid limit, how the data corresponds to Hansbo’s (1957) and Swedish Geotechnical Institute’s (2007) linear empirical correlations, and the correction factor applied to shear strength measured by the fall cone test. The results of the study show that the correction factor typically reduces the shear strength from fall cone tests too much with respect to shear strength from direct simple shear tests. The normalized shear strength’s dependency on liquid limit may be rejected for the fall cone test data. The results for direct simple shear test data however, indicates a correlation with liquid limit. The data scatter is considerable, especially for fall cone test data, and the relevance of describing the normalized shear strength from fall cone test with a linear empirical correlation to liquid limit may conclusively be questioned. / Skjuvhållfasthet och förkonsolideringstryck är två viktiga jordparametrar för lösa leror. Båda parametrar reflekterar lerans struktur och spänningstillstånd, och empiriska korrelationer för odränerad skjuvhållfasthet, normaliserad mot förkonsolideringstrycket, används därför ofta för att bedöma en leras egenskaper. De empiriska korrelationerna är vanligen kopplade till flytgräns eller plasticitetsindex. Dessa korrelationer har däremot ifrågasatts av studier som i vissa fall istället föreslagit ett konstant förhållande mellan normaliserad odränerad skjuvhållfasthet och plasticitetsgränser. Mätvärden från geotekniska projekt i Sverige visar allmänt stor spridning avseende dessa parametrar och data avviker ofta från etablerade empiriska korrelationer. I examensarbetet har data från direkta skjuvförsök, ödometerförsök och fallkonförsök utvärderats statistiskt och kvalitativt. Totalt omfattar studien 596 jordprover från 146 provtagningspunkter från Stockholm, Göteborg och Uppsala. Syftet med studien är att undersöka korrelationen mellan odränerad skjuvhållfasthet och förkonsolideringstryck. Studien behandlar den normaliserade skjuvhållfashetens flytgränsberoende, Hansbos (1957) och Statens Geotekniska Instituts (2007) empiriska korrelationer, samt den korrektionsfaktor som ska tillämpas på skjuvhållfastheter från fallkonförsök. Resultatet visar att korrektionsfaktorn reducerar skjuvhållfastheten för mycket och att korrigerade skjuvhållfastheter är i sämre samstämmighet med skjuvhållfastheter från direkta skjuvförsök än okorrigerade. Data från fallkonförsök uppvisar inget tydligt flytgränsberoende, medan resultaten från direkta skjuvförsök indikerar ett beroende. Spridningen i data är dock påfallande, särskilt för fallkonförsöket. Relevansen i att tillämpa en linjär empirisk korrelation för odränerad normaliserad från fallkonförsök mot förkonsolideringstryck beroende av flytgräns bör ifrågasättas.

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