A concepção deste trabalho está ligada ao desenvolvimento de sistemas microeletromecânicos (MEMS) para RF na faixa de frequências de ondas milimétricas. Dentro deste contexto, o Grupo de Novos Materiais e Dispositivos (GNMD) do Laboratório de Microeletrônica (LME) da Escola Politécnica da Universidade de São Paulo (EPUSP) já fabricou RF MEMS que tiveram resultados bastante promissores. No entanto, para obtenção de melhores resultados, é necessária a otimização eletromecânica destes dispositivos e para isso é necessária a extração de suas propriedades mecânicas. Assim, este trabalho teve como objetivo o desenvolvimento de uma metodologia para extração do módulo de elasticidade e tensão residual em MEMS, através da simulação e fabricação de microestruturas específicas para este fim. As técnicas de nanoindentação, frequência de ressonância, raio de curvatura e M-TEST foram estudadas. As microestruturas fabricadas foram cantileveres e pontes feitas de alumínio e cobre. Foram realizadas simulações no software ANSYS para prever as frequências de ressonância e as tensões de pull-in das estruturas antes de serem fabricadas. O módulo de elasticidade do alumínio extraído através da nanoindentação foi de 75,6 ± 4,1 GPa, e o do cobre extraída através da técnica de frequência de ressonância foi de 123 ± 12 GPa. A tensão residual do cobre foi extraída através da técnica de medição do raio de curvatura e foi de -199±105 MPa. O trabalho está vinculado ao projeto Jovem Pesquisador FAPESP (2011/18167-3). / The approach of this work is linked to the development of microelectromechanical systems (MEMS) for RF in the frequency range of millimeter waves. Within this context, the Group of New Materials and Devices (GNMD) of the Laboratory of Microelectronics (LME) of the Polytechnic School of the University of São Paulo (EPUSP) has already manufactured RF MEMS which have had very promising results. However, to obtain better results, it is necessary the electromechanical optimization of these devices through the extraction of their mechanical properties. Thus, this work has the objective of developing a methodology for the extraction of the Young\'s modulus and residual stress in MEMS, through the simulation and fabrication of specific microstructures for this purpose. The techniques of nanoindentation, resonance frequency, radius of curvature and M-TEST were studied. The fabricated microstructures were cantilevers and bridges in aluminum and copper materials. Simulations were performed in the ANSYS software to predict the resonance frequencies and the pull-in voltages of the structures before they were fabricated. The Young\'s modulus of aluminum extracted through nanoindentation was 75,6 ± 4,1 GPa, the resonance frequency of copper extracted by the technique of the same name was 123 ± 12 GPa and the residual stress of copper was extracted through the technique of measuring the radius of curvature and was -199±105 MPa. The work is linked to the project Jovem Pesquisador from FAPESP (2011/18167-3).

Esta dissertação insere-se nas áreas de qualidade laboratorial e de ensaios de controle de concreto, especificamente quanto à propriedade módulo estático de deformação ou módulo de Young. A motivação do trabalho é a elevada variabilidade de resultados experimentais observada pelo meio técnico nacional em ensaios interlaboratoriais, cujos resultados indicam desvios-padrão totais da ordem de 3,5 GPa, valor significativo para o controle tecnológico de obras de construção civil. Os objetivos buscados foram a identificação das parcelas da variabilidade oriundas da produção e do ensaio, com especial atenção àquela originada na instrumentação para medida das deformações durante o ensaio, e a discussão da aplicabilidade do conceito semiprobabilístico normativo à propriedade módulo de deformação do concreto. Além disso, a própria discussão da aplicabilidade da sistemática de pesquisa e análise sobre este tipo de ensaio e de material constou como um objetivo do trabalho. Para tal, desenvolveu-se um programa experimental em duas etapas: a primeira foi destinada às avaliações de acurácia (precisão e exatidão) do método de ensaio. As avaliações se deram segundo roteiros da área metrológica para validação de métodos e sistemas de medida. De quatro instrumentações para medida das deformações testadas, uma se mostrou mais precisa (identificada como clip gages) e outra se mostrou a mais suscetível a erros sistemáticos e aleatórios entre as testadas (identificada como compressômetro com dois relógios comparadores). Recomendou-se a ampliação do programa experimental para o âmbito interlaboratorial, pois, a rigor, o método de ensaio vigente não poderia ser considerado validado em termos de acurácia baseando-se unicamente nos resultados deste programa experimental. Porém, concluiu-se pela possibilidade de aceitação prática do método independentemente da utilização de três de um total de quatro tipos de instrumentação para medida das deformações testados em ensaio, sem que houvesse prejuízo para a produção ou o controle tecnológico usual desta propriedade. Na segunda etapa, obteve-se um Diagrama de Dosagem e estudou-se um cenário de fornecimento de concreto sob critérios estatísticos diferentes de atendimento à especificação de módulo de deformação: utilização do valor característico e do valor médio, com diferença de 4 GPa entre eles. Estimou-se um aumento da ordem de 9% no deslocamento vertical de uma viga simples bi-apoiada quando executada com o concreto de menor módulo em relação à execução com o de maior módulo. Por sua vez, o concreto de maior módulo exigiria um aumento no consumo de cimento da ordem de até 200 kg/m3, se conservados todos os insumos materiais e os demais parâmetros tecnológicos contidos nos traços. Concluiu-se pela aplicabilidade do uso da sistemática empregada na avaliação da acurácia do método de ensaio e do uso do conceito semiprobabilístico para esta propriedade. / This work is developed into the areas of laboratorial quality and concrete control tests, specifically focusing on the static modulus of elasticity or Young´s modulus. The motivation of this work is the high variability of experimental results observed by national technicians in interlaboratorial tests. These results show total standard deviations of around 3.5 GPa, a significant value for the technological control for civil construction. The main objectives are the identification of the variability fragments derived from the production and test, specially the ones related to the instrumentation for measuring deformations during the test, and the discussion of the semi-probabilistic concept applicability on the concrete Young´s modulus control. Moreover, the discussion of the applicability of the procedure used in this work and its analysis are also objective pursued here. The experimental program was developed in two steps: the first step covered the accuracy assessments (precision and exactness) of test method. The assessments were carried out according to instructions from Metrology concepts for the validation of the methods and the measure systems. One out of four instrumentations for measuring the tested deformations proved to be more precise (identified as clip gages) and another one proved to be more susceptible to systematic and random errors (identified as a compressometer with two dial indicators). The extension of the experimental program to an interlaboratorial scope is recommended because the current test method could not be considered valid based only on the results of this experimental program. However, it was shown that the practical acceptance of the test method for three among the four kinds of instrumentations analyzed, without damaging the production or the usual technological control of this property, is possible. On the second step, a mix design diagram was obtained and a case of supply of concrete under different statistical criteria (fulfillment the modulus of elasticity specification): the use of the characteristic value and the average value, with difference of 4 GPa between them. An increase of 9% on the vertical transference of a simple dual supported beam was observed when using a lower modulus concrete, when compared to another one with a higher modulus. On the other hand, the modulus increase would require an increment in the cement consumption up to 200 kg per cubic meter, if all the material inputs and further technological parameters is maintained. The final conclusion was that the procedure used on the assessment of the test method accuracy and the semi-probabilistic concept on this material property is applicable.

L'adolescence constitue une période de construction de soi pendant laquelle tant l'intériorité que le corps physique se transforment. Cette métamorphose change le rapport des jeunes aussi bien au monde, qu'au corps et qu'à la lecture. Leurs pratiques dans ce domaine sont très variées et sont souvent mises en concurrence avec d'autres activités. Certains sont en rupture avec le livre- perçu comme un objet contraignant- alors qu'il est très présent à l'école. Quel rapport l'élève entretient-il avec cet objet ? Quels sont ses pratiques et ses comportements de lecteur ? Inscrite dans une approche bibliologique (Otlet, Estivals) des phénomènes médiateurs et anthropologique des comportements (Lévi-Strauss, Monod) cette recherche à partir de la production de dessins que nous décrivons et analysons grâce aux langages documentaires -d'ordinaire utilisés par les professionnels de l'information-, opère un glissement du portrait du lecteur à la scène de lecture. Porteurs d'indices et de détails signifiants et croisés avec des entretiens, nous interprétons la matière informative recueillie à l'aide d'une grille d'observation et d'interprétation élaborée spécifiquement. Cet outil d'analyse de contenu, construit à partir d'un lexique spécifique lié à la pratique observée, permet de traduire le langage graphique en mots. Le dessin, comme méthode visuelle et sensible, révèle des pratiques, des postures, des attitudes, des comportements, des rituels de lecture et des ressentis. Ainsi, en montrant des sujets agissants et couplé à d'autres méthodes d'investigation, le dessin nous paraît apte à révéler une conscience de soi lecteur et à assurer la médiation entre ce dernier et le livre. / The teen years is a self-construction period : inner character and physical body are transformed. For the teenagers, this metamorphosis modifies their relationship to the world, their body and also their reading choises. In the field of reading, their practices are very different, frequently in competition with others activities. Some teenagers have broken away from the book sensed as a limiting object, despite its presence in the school environment. What kind of relationship exists between the pupils and this object ? What kind of practices and behaviours do they adopt as readers ? In keeping with the biblilogic approach (Otlet, Estivals) of the mediator and that of the anthropological phenomena of behaviours (Lévi-Strauss, Monod), the production of drawings described and analyzed through the indexing language - usually used by the information professionals - is the starting point of this research which undertakes a shift from the portrait of the reader to the reading scene. Whilst bringing significant clues and details alongside interviews, we analysed the collected informative material using an observation and interpretation table that we have specifically developed. This analysis tool constructed from specific lexicon linked with the observed practice is a way to translate the graphic language into words. The drawing, considered as a visual and sensitive method, reveals some practices, postures, attitudes, behaviours, reading rituals and perceptions. Finally, showing active subjects and with our approach supplemented by other investigation methods, drawings seems to be able to reveal a self-consciousness as reader and to act as mediator between the latter and the book.

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The development of the layer-by-layer (LbL) technique has turned out to be an efficient way to physically modify the surface properties of different materials, for example to improve the adhesive interactions between fibers in paper. The main objective of the work described in this thesis was to obtain fundamental data concerning the adhesive properties of wood biopolymers and LbL films, including the mechanical properties of the thin films, in order to shed light on the molecular mechanisms responsible for the adhesion between these materials. LbLs constructed from poly(allylamine hydrochloride) (PAH)/poly(acrylic acid) (PAA), starch containing LbL films, and LbL films containing nanofibrillated cellulose (NFC) were studied with respect to their adhesive and mechanical properties. The LbL formation was studied using a combination of stagnation point adsorption reflectometry (SPAR) and quartz crystal microbalance with dissipation (QCM-D) and the adhesive properties of the different LbL films were studied in water using atomic force microscopy (AFM) colloidal probe measurements and under ambient conditions using the Johnson-Kendall-Roberts (JKR) approach. Finally the mechanical properties were investigated by mechanical buckling and the recently developed SIEBIMM technique (strain-induced elastic buckling instability for mechanical measurements). From colloidal probe AFM measurements of the wet adhesive properties of surfaces treated with PAH/PAA it was concluded that the development of strong adhesive joints is very dependent on the mobility of the polyelectrolytes and interdiffusion across the interface between the LbL treated surfaces to allow for polymer entanglements. Starch is a renewable, cost-efficient biopolymer that is already widely used in papermaking which makes it an interesting candidate for the formation of LbL films in practical systems. It was shown, using SPAR and QCM-D, that LbL films can be successfully constructed from cationic and anionic starches on silicon dioxide and on polydimethylsiloxane (PDMS) substrates. Colloidal probe AFM measurements showed that starch LbL treatment have potential for increasing the adhesive interaction between solid substrates to levels beyond those that can be reached by a single layer of cationic starch. Furthermore, it was shown by SIEBIMM measurements that the elastic properties of starch-containing LbL films can be tailored using different nanoparticles in combination with starch. LbL films containing cellulose I nanofibrils were constructed using anionic NFC in combination with cationic NFC and poly(ethylene imine) (PEI) respectively. These NFC films were used as cellulose model surfaces and colloidal probe AFM was used to measure the adhesive interactions in water. Furthermore, PDMS caps were successfully coated by LbL films containing NFC which enabled the first known JKR adhesion measurements between cellulose/cellulose, cellulose/lignin and cellulose/glucomannan. The measured adhesion and adhesion hysteresis were similar for all three systems indicating that there are no profound differences in the interaction between different wood biopolymers. Finally, the elastic properties of PEI/NFC LbL films were investigated using SIEBIMM and it was shown that the stiffness of the films was highly dependent on the relative humidity. / <p>QC 20110923</p>

La prédiction de la géométrie d'une pièce mise en forme par déformation plastique grâce à un logiciel de calcul par éléments finis (EF) s'effectue en suivant séquentiellement différentes étapes : la caractérisation thermo-mécanique du matériau, la modélisation de son comportement et son intégration dans un logiciel EF, puis la mise en données et la simulation de l'opération de formage. La phase de modélisation consiste entre autre à identifier quel type de modèle de comportement est le plus approprié pour prédire les réactions du matériau lors de l'opération de formage. Ces modèles sont essentiellement développés dans le cadre de la mécanique des milieux continus (MMC). L'hypothèse forte, si ce n'est centrale, de la MMC consiste à considérer que les variables qui servent à déterminer le comportement du matériau sont continues et dérivables. Cependant, les connaissances les plus élémentaires de métallurgie indiquent que les grandeurs locales dans les matériaux métalliques sont discontinues. La majorité des modèles de comportement mécanique des matériaux métalliques repose sur la définition d'un volume élémentaire représentatif dont la taille est assez grande pour permettre une homogénéisation de la description du comportement en gommant l'influence des hétérogénéités localesL'objet de ces travaux est de montrer que la prise en compte des hétérogénéités locales dans la modélisation du comportement des matériaux métalliques est pertinente et contribue à l'amélioration de la prédiction des simulations d'opérations de mise en forme en élargissant le potentiel prédictif des modèles ainsi construits. Un modèle élasto-plastique prenant en compte les hétérogénéités locales est alors proposé. / To obtain a relevant shape of a formed part during its finite element simulation, several steps are needed: thermo-mechanical caracterization of the material, definition of the most relevant model and integration of this model in the FE software and finally after data converting and computing processes. The modelling step include, among other things, the identification of the most appropriate model to fit the experimental material behaviour. Those models are essentially developped within the framework of continuum mechanics (CM). A strong, if not the main assumption of the CM consists in considering that mechanical description variables are continuous and differentiable. However, the basic knowledge of metallurgy indicates that local data in metallic materials are discontinuous. For metallic materials, the majority of constitutive models are based on the definition of a representative elementary volume (REV). This REV is supposed to be large enough to erase the incidence of local heterogeneities. Then those constitutive models are assumed to be homogeneous.The aim of this work is to show that introducing local heterogeneities in the description of constitutive models is relevant and contribute to improve the simulation accuracy. Those models also provide an enlargement of the simulation predictive potential. Then an elasto-plastic model, based on local heterogeneities description, is proposed.

O presente trabalho discute comparativamente o comportamento mecânico de solos lateríticos e não lateríticos para uso em pavimentação. Para tanto foram ensaiados 3 pares de solos, sendo cada par constituído por solos de curvas granulométricas semelhantes, mesma classificação HRB e comportamentos distintos quanto à laterização. Foram realizados ensaios triaxiais convencionais do tipo CD saturado e não saturado sem controle de sucção e ensaios de compressão simples. A partir dos resultados dos ensaios foram modeladas as deformações elásticas em função das tensões de confinamento e determinadas as envoltórias de ruptura de Mohr-Coulomb. Concluiu-se que a maior resistência dos solos lateríticos está representada na componente coesão da envoltória de Mohr-Coulomb e que esta é mobilizada praticamente ao máximo desde o início em um ensaio triaxial. A diferença de resistência entre os ensaios saturados e não saturados também se mostrou na coesão, com a soma nesta da componente coesão aparente, fruto da sucção. O ângulo de atrito mostrou-se constante para as duas gêneses, tanto para a condição saturada como para a condição não saturada. Os solos lateríticos apresentam rigidez maior que os não lateríticos, tanto na condição saturada como na condição não saturada. Para os níveis de tensão de confinamento utilizados, a rigidez dos solos, de ambas as gêneses, na condição saturada, diminui com o aumento da tensão confinante. Também se observou que a ação da sucção existente nos ensaios não saturados proporciona, para ambas as gêneses, uma mudança da sensibilidade da rigidez ao aumento da tensão confinante. / The present paper discusses the mechanical behavior of lateritic and no-lateritic soils for use in pavement. To attain that goal, 3 pair soils were rehearsed, being each pair constituted by soils of similar granulometric curves, same HRB classification and different genesis. The experimental program was constituted of static triaxial compression test of the type saturated CD and of the type unsaturated without suction control and unconfined compression strength test. With the results of the tests, the elastic strains were modeled in function of the confinement stresses and the rupture paths of Mohr-Coulomb were determined. The analysis that the shear strength of the lateritic soils is greater than no-lateritic soil because of the cohesion. Since the begin it, the cohesion is mobilized practically to the maximum for both soils. The difference of shear strength between the saturated and unsaturated tests it is also cohesion, with the sum in that component of the cohesion apparent produced for suction. The angle of internal friction is constant for the two genesis as much for the saturated test as for the unsaturated test. The lateritic soils present greater stiffness than the no-lateritic soils, as much for saturated test as for unsaturated test. For the levels of confinement stresses used, in the saturated condition the stiffness of the soils decreases with the increase of the confinement stresses of both genesis. In addition, it was observed that the suction existent in the unsaturated testing produce a change of the sensibility of the soils stiffness to the increase of the confinement stress for both genesis.

Esta dissertação insere-se nas áreas de qualidade laboratorial e de ensaios de controle de concreto, especificamente quanto à propriedade módulo estático de deformação ou módulo de Young. A motivação do trabalho é a elevada variabilidade de resultados experimentais observada pelo meio técnico nacional em ensaios interlaboratoriais, cujos resultados indicam desvios-padrão totais da ordem de 3,5 GPa, valor significativo para o controle tecnológico de obras de construção civil. Os objetivos buscados foram a identificação das parcelas da variabilidade oriundas da produção e do ensaio, com especial atenção àquela originada na instrumentação para medida das deformações durante o ensaio, e a discussão da aplicabilidade do conceito semiprobabilístico normativo à propriedade módulo de deformação do concreto. Além disso, a própria discussão da aplicabilidade da sistemática de pesquisa e análise sobre este tipo de ensaio e de material constou como um objetivo do trabalho. Para tal, desenvolveu-se um programa experimental em duas etapas: a primeira foi destinada às avaliações de acurácia (precisão e exatidão) do método de ensaio. As avaliações se deram segundo roteiros da área metrológica para validação de métodos e sistemas de medida. De quatro instrumentações para medida das deformações testadas, uma se mostrou mais precisa (identificada como clip gages) e outra se mostrou a mais suscetível a erros sistemáticos e aleatórios entre as testadas (identificada como compressômetro com dois relógios comparadores). Recomendou-se a ampliação do programa experimental para o âmbito interlaboratorial, pois, a rigor, o método de ensaio vigente não poderia ser considerado validado em termos de acurácia baseando-se unicamente nos resultados deste programa experimental. Porém, concluiu-se pela possibilidade de aceitação prática do método independentemente da utilização de três de um total de quatro tipos de instrumentação para medida das deformações testados em ensaio, sem que houvesse prejuízo para a produção ou o controle tecnológico usual desta propriedade. Na segunda etapa, obteve-se um Diagrama de Dosagem e estudou-se um cenário de fornecimento de concreto sob critérios estatísticos diferentes de atendimento à especificação de módulo de deformação: utilização do valor característico e do valor médio, com diferença de 4 GPa entre eles. Estimou-se um aumento da ordem de 9% no deslocamento vertical de uma viga simples bi-apoiada quando executada com o concreto de menor módulo em relação à execução com o de maior módulo. Por sua vez, o concreto de maior módulo exigiria um aumento no consumo de cimento da ordem de até 200 kg/m3, se conservados todos os insumos materiais e os demais parâmetros tecnológicos contidos nos traços. Concluiu-se pela aplicabilidade do uso da sistemática empregada na avaliação da acurácia do método de ensaio e do uso do conceito semiprobabilístico para esta propriedade. / This work is developed into the areas of laboratorial quality and concrete control tests, specifically focusing on the static modulus of elasticity or Young´s modulus. The motivation of this work is the high variability of experimental results observed by national technicians in interlaboratorial tests. These results show total standard deviations of around 3.5 GPa, a significant value for the technological control for civil construction. The main objectives are the identification of the variability fragments derived from the production and test, specially the ones related to the instrumentation for measuring deformations during the test, and the discussion of the semi-probabilistic concept applicability on the concrete Young´s modulus control. Moreover, the discussion of the applicability of the procedure used in this work and its analysis are also objective pursued here. The experimental program was developed in two steps: the first step covered the accuracy assessments (precision and exactness) of test method. The assessments were carried out according to instructions from Metrology concepts for the validation of the methods and the measure systems. One out of four instrumentations for measuring the tested deformations proved to be more precise (identified as clip gages) and another one proved to be more susceptible to systematic and random errors (identified as a compressometer with two dial indicators). The extension of the experimental program to an interlaboratorial scope is recommended because the current test method could not be considered valid based only on the results of this experimental program. However, it was shown that the practical acceptance of the test method for three among the four kinds of instrumentations analyzed, without damaging the production or the usual technological control of this property, is possible. On the second step, a mix design diagram was obtained and a case of supply of concrete under different statistical criteria (fulfillment the modulus of elasticity specification): the use of the characteristic value and the average value, with difference of 4 GPa between them. An increase of 9% on the vertical transference of a simple dual supported beam was observed when using a lower modulus concrete, when compared to another one with a higher modulus. On the other hand, the modulus increase would require an increment in the cement consumption up to 200 kg per cubic meter, if all the material inputs and further technological parameters is maintained. The final conclusion was that the procedure used on the assessment of the test method accuracy and the semi-probabilistic concept on this material property is applicable.

Reinforced concrete frames, infilled with brick/concrete block masonry, are the most common type of structures found in multi-storeyed constructions, especially in developing countries. Usually, the infill walls are considered as non-structural elements even though they alter the lateral stiffness and strength of the frame significantly. Approximately 80% of the structural cost from earthquakes is attributable to damage of infill walls and to consequent damages of doors, windows and other installations. Despite the broad application and economical significance, the infill walls are not included in the analysis because of the design complexity and lack of suitable theory. But in seismic areas, ignoring the infill-frame interaction is not safe because the change in the stiffness and the consequent change in seismic demand of the composite structural system is not negligible. The relevant experimental findings shows a considerable reduction in the response of infilled frames under reverse cyclic loading. This behaviour is caused by the rapid degradation of stiffness, strength, and low energy dissipation capacity resulting from the brittle and sudden damage of the unreinforced masonry infill walls. Though various national/international codes of practice have incorporated some of the research outcomes as design guidelines, there is a need and scope for further refinement. In the initial part of this work, a numerical modelling and linear elastic analysis of masonry infilled RC frames has been done. A multi-storey multi-bay frame infilled with masonry panels, is considered for the study. Both macro modelling and micro modelling strategies are adopted. Seismic loading is considered and an equivalent static analysis as suggested in IS 1893, 2002 is done. The results show that the stiffness of the composite structure is increased due to the obvious confinement effects of infill panels on the bounding frame. A parametric study is conducted to investigate the influence of size and location of openings, presence/absence of infill panels in a particular storey and elevation irregularity in terms of floor height. The results show that the interaction of infill panel changes the seismic response of the composite structure significantly. Presence of openings further changes the seismic behaviour. Increase in openings increases the natural period and introduce newer failure mechanisms. Absence of infill in a particular storey (an elevation irregularity) makes it drift more compared to adjacent storeys. Since the structural irregularities influence the seismic behaviour of a building considerably, we should be cautious while construction and renovation of such buildings in order to take the advantage of increased strength and stiffness obtained by the presence of infill walls. A nonlinear dynamic analysis of masonry infilled RC frames is presented next. Material non linearity is considered for the finite element modelling of both masonry and concrete. Concrete damage plasticity model is employed to capture the degradation in stiffness under reverse cyclic loading. A parametric study by varying the same parameters as considered in the linear analysis is conducted. It is seen that the fundamental period calculation of infilled frames by conventional empirical formulae needs to be revisited for a better understanding of the real seismic behaviour of the infilled frames. Enhancement in the lateral stiffness due to the presence of infill panel attracts larger force and causes damage to the composite system during seismic loading. Elevation irregularities included absence of infill panels in a particular storey. Soft storey shows a tendency for the adjacent columns to fail in shear, due to the large drift compared to other storeys. The interstorey drift ratios of soft storeys are found to be larger than the limiting values. However this model could not capture the separation at the interfaces and related failure mechanisms. To improve the nonlinear model, a contact surface at the interface is considered for a qualitative analysis. A one bay one storey infilled frame is selected. The material characteristics were kept the same as those used in the nonlinear model. Contact surface at the interface was given hard contact property with pressure-overclosure relations and suitable values of friction at the interface. This model could simulate the compressive diagonal strut formation and the switching of this compressive strut to the opposite diagonal under reverse cyclic loading. It showed an indication of corner crushing and diagonal cracking failure modes. The frame with central opening showed stress accumulation near the corners of opening. Next, the micro modelling strategy for masonry suggested by Lourenco is studied. This interface element can be used at the masonry panel-concrete frame interface as well as at the expanded masonry block to block interface. Cap plasticity model (modified Drucker – Prager model for geological materials) can be used to describe the behaviour of masonry (in terms of interface cracking, slipping, shearing) under earthquake loading. The blocks can be defined as elastic material with a potential crack at the centre. However, further experimental investigation is needed to calibrate this model. It is required to make use of the beneficial effects and improve upon the ill-effects of the presence of infills. To conclude, infill panels are inevitable for functional aspects such as division of space and envelope for the building. Using the lateral stiffness, strength contribution and energy dissipation capacity, use of infill panels is proposed to be a wiser solution for reducing the seismic vulnerability of multi-storey buildings.

Les enrobés bitumineux ont été utilisés habituellement dans des constructions routières et récemment sous les ballasts des ferroviaires. Sa grande rigidité aux températures relativement basses de l’ambiance et à haute fréquence explique son application répandue en Europe du nord. Ce matériau a été étudié au niveau global par à la fois des essais empiriques, expérimentaux et des approches analytiques. Pourtant, l’enrobé bitumineux possède un structure interne hétérogène et complexe qui peut-être engendrer des comportements complexe. Les analyses au niveau local permettent alors de compléter les connaissances de ses comportements.De nos jours, la méthode des éléments discrets est connue comme un outil numérique répandu dans le domaine granulaire. Elle peut modéliser son comportement à travers des modèles locaux et fournir des informations de sa structure interne. Une part, cette méthode considère que les particules sont quasi-solides. Son déplacement est régi par les lois de mouvement. L’autre part, le chevauchement au niveau de contact entre particules est admis. L’interpénétration des particules est calculée par les lois de contact locaux associées. Cette thèse constitue une maquette numérique des enrobés bitumineux dont les particules isolées s’interagissent à travers des lois d’interaction à distance. Cette maquette prend en compte la granulométrie des granulats (>1mm) et son rapport volumique vis-à-vis du mastic constitué par des grains (<1mm), le liant et des vides. Les granulats (>1mm) seuls sont modélisés par des particules numériques, tandis que du mastic est pris en compte par des lois d’interaction. Au premier lieu, une simulation élastique est réalisée afin de reproduire des comportements asymptotiques élastiques d’un enrobé bitumineux de référence de type GB3 qui apparaissent lors des conditions extrêmes (fréquence ou température). Des lois d’interaction élastiques ont appliqué à la maquette numérique créée. Sur deux directions normale et tangentielles, les raideurs du ressort et leur rapport sont constantes.Ensuite, les simulations viscoélastiques sont réalisées pour reproduire le comportement viscoélastique du même matériau de référence. Au premier temps, une loi d’interaction de type Kelvin-Voigt est utilisée pour mettre en évidence qualitativement l’application d’une loi viscoélastique. Ensuite, le comportement viscoélastique globale est modélisé à niveau des particules par quelques lois d’interaction de type 1KV1R (un Kelvin-Voigt et un ressort en série) repartant au réseau d’interaction de la maquette numérique. Les raideurs des ressorts prenant en compte la géométrie de l’interface de particules sont constantes pour toutes les modèle de 1KV1R. Cependant, des viscosités des amortisseurs sont différentes. Certaines hypothèses sont examinées pour distribuer ses viscosités dans le réseau d’interaction. A la fin des études, les analyses des efforts internes sont réalisées. / Bituminous mixtures have traditionally been used in road constructions and recently under railway ballast. Its high rigidity at relatively low ambient temperatures and high frequency explains its widespread application in northern Europe. This material has been studied at the global level by both empirical, experimental and analytical approaches. However, the asphalt has a heterogeneous internal structure and complex which may cause complex behavior. The analysis at the local level then make it possible to supplement the knowledge of its behaviors.Nowadays, the method of discrete elements is known as a numerical tool spread in the granular field. It can model its behavior through local models and provide information about its internal structure. On the one hand, this method considers that the particles are quasi-solid. Its displacement is governed by the laws of motion. On the other hand, the overlap at the particle contact level is allowed. The interpenetration of the particles is calculated by the associated local contact laws. This thesis constitutes a numerical model of bituminous mixes whose isolated particles interact through laws of interaction at a distance. This model takes into account the granulometry of the aggregates (> 1 mm) and its volume ratio with respect to the mastic constituted by grains (<1 mm), the binder and voids. The aggregates (> 1 mm) alone are modeled by numerical particles, while mastic is taken into account by laws of interaction.First, an elastic simulation is performed in order to reproduce the elastic asymptotic behaviors of a reference bituminous mix of GB3 type that appear during extreme conditions (frequency or temperature). Elastic interaction laws have applied to the created numerical model. In both normal and tangential directions, the stiffness of the spring and its ratio are constant.Then, the viscoelastic simulations are performed to reproduce the viscoelastic behavior of the same reference material. At first, a Kelvin-Voigt interaction law is used to qualitatively highlight the application of a viscoelastic law. Then, the global viscoelastic behavior is modeled at the level of the particles by some laws of interaction of type 1KV1R (a Kelvin-Voigt and a spring in series) leaving again to the network of interaction of the numerical model. The stiffness of the springs taking into account the geometry of the particle interface is constant for all models of 1KV1R. However, the viscosities of the dashpots are different. Some hypotheses are examined to distribute its viscosities in the interaction network. At the end of the studies, the analysis of the internal efforts are carried out.