Dissertations / Theses on the topic 'Mousse (chimie) – Propriétés mécaniques'
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Imbert, Claire. "Matériaux à propriétés mécaniques et thermiques améliorées sous pression hydrostatique en utilisation aquatique." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20019.
Full textMaterials nowadays used for thermal insulation in aquatic environment under hydrostatic pressure are either rubber flexible foams or rigid foams, especially syntactic foams, depending on depth. These flexible materials were analyzed through classical mechanical and thermal tests. However, methods and results were adapted to the final usage of the product, particularly to the aquatic environment at the surface and under depth. Relationships between structures and properties characteristics were studied to define appropriate properties within relevant criteria. Moreover, to underline thermal properties under hydrostatic pressure, a testing instrument has been developed: an innovating hyperbaric test chamber, dedicated to under water pressure thermal resistance and thickness measurements, from 0 to 50 m depth. Strengths and weak points of these classical materials have been clearly established. Results analysis lead to a new concept of composite material for the defined usage. This innovating material, a syntactic foam, has been developed. By varying the particle type added to a thermoplastic elastomer matrix, the cellular structure has been refined in order to obtain a similar behaviour in aquatic environment, at the surface like in depth. This material has been tested, parallel to its industrial production, to identify relationships between structures and properties
Mechraoui, Ahmed. "Sandwich composite de mousses polymères." Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27452/27452.pdf.
Full textThe aim of this work is to produce and characterize polypropylene structural composite foams. To do so, the work is divided in three parts. The first part is devoted to study the reinforcement of polypropylene with hemp fibres by changing the fibre content, fibre size and coupling agent concentration. Micrographs are used to explain the results of the mechanical properties measured under tensile and flexural stress. It is found that 2% of coupling agent gives the optimum modulus values. In the second part, polypropylene foams are produced by compression moulding with different concentrations of blowing agent to determine the effect of density reduction and density profile on the tensile and flexural properties. The morphological characteristics (cell size, cell density and skin thickness) of the foams are also examined. It is found that the use of the complete density profile is necessary to predict with high precision the mechanical results. Finally, sandwich structures are produced with different skin ratio and core densities. A complete morphological analysis is reported with mechanical properties (tensile and flexural). It is shown that the simple law of mixture and the square power-law combined with the density profile are enough to predict the effect of the skins and core, respectively.
Yao, Jiaolian. "DENSITY GRADED LMDPE FOAMS PRODUCED UNDER A TEMPERATURE GRADIENT: MORPHOLOGY AND PROPERTIES." Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/28072/28072.pdf.
Full textIn this work, linear medium density polyethylene (LMDPE) and Expancel microbeads were used to produce density graded polymer foams using compression molding. By controlling independently the top and bottom plate temperatures in the mold, different temperatures and molding times were used to produce symmetric and asymmetric foams. The effect of blowing agent type and content were also studied to control the density profile and foam morphology (cell size and cell density) across thickness. Finally, the mechanical behavior in flexion and tension is reported and discussed in relation with foam morphology and structure.
Chen, Xiao Yuan. "Mousses structurales asymétriques de polymères." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25085/25085.pdf.
Full textBégin, Mathieu. "Effet de la ligne de soudure sur le polypropylène renforcé de fibres de verre et moussé par injection." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24849/24849.pdf.
Full textDelgado, Sánchez Clara. "Nouvelles méthodes d’optimisation et de caractérisation de mousses à base de tanins pour l’isolation thermique du bâtiment." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0246/document.
Full textIn this thesis, foams based on more than 90% of natural products and with an exceptionally low thermal conductivity have been studied in depth. The main objective of this work was to improve some of the weaknesses of those materials and to solve problems that might be encountered during use, for allowing them to compete with other synthetic foams that are currently on the thermal insulation market. New methodologies have been proposed to optimise tannin-based foams from different points of view. First, liquid foams were analysed in terms of stability and polymerisation process using a backscattered light analyser, in order to convert them into improved rigid tannin-based foams. Experimental design was also used to improve the mechanical properties of physically blown rigid foams without prejudicing their thermal conductivity. On the other hand, hydrophobisation treatments were suggested for reducing the sensitivity of those foams to water in liquid or vapour form, and the effect of formulations’ ingredients on their fire properties were elucidated. Finally, two techniques of mechanical characterisation were investigated and compared, leading to Poisson’s coefficient and loss factor, and evidencing the precautions to be taken for characterising brittle foams
Dallagi, Heni. "Numerical and experimental investigations of the rheological behavior of foam flow : application to the cleaning of surfaces contaminated by microorganisms in the food industries." Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR003.
Full textIn this research, experimental and numerical characterization of the rheological behavior of an aqueous foam flowing inside a horizontal pipe with and without singularities (presence of half-sudden expansion, and a fence) were investigated. Different conditions of foam flow were studied by varying the foam qualities (from 55% to 85%), and three Reynolds numbers (32, 65, and 97). Measurements of the pressure measurements, and at the wall the local velocity repartition and the thickness of the liquid films using respectively pressure sensors, Particle Image Velocimetry, and a conductimetry technique shown a reorganization of the foam downstream the geometry change, with a thicker liquid film at the duct bottom, larger bubble sizes at the top, as well as a larger foam void fraction increased from the bottom to the top part of the duct section. In addition, foam would present a visco-elastic character comparable to a non-Newtonian monophasic liquid. Computational Fluid Dynamics simulations were undertaken to predict this rheological behavior of the foam, the two models Herschel-Bulkley and Bingham were tested taken into account the presence of an underlying liquid film at the bottom of the channel . Comparison between experimental and numerical results showed that regardless of the foam quality, Herschel-Bulkley model could accurately describe the rheological behaviour of the aqueous foam under the different flow conditions analysed.The second target was to investigate the ability of a wet foam flow (quality of 50%) to clean stainless-steel surfaces contaminated by microorganisms. For this purpose, two different contamination patterns were studied, droplets containing Bacillus subtilis spores (either hydrophilic Bs PY79 or hydrophobic Bs PY79 spsA), and biofilms produced by three bacteria strains encountered in food industry production plants (Escherichia coli SS2, Bacillus cereus 98/4, and Pseudomonas fluorescens Pf1). Different flow conditions were performed by varying the wall shear stresses (2.2 - 13.2 Pa), and bubble sizes (0.18-0.34 mm) in a straight duct with no geometrical changes, in order to identify the mechanisms of contamination release and thus better control and optimize the foam cleaning process. Results show that compared to conventional cleaning-in-place, foam flow effectively removed Bs spores as well as Bc-98/4, Ec-SS2, and Pf1 biofilms. Moreover, the combination of high shear stress at the wall and small bubble sizes (<0.2 mm) showed promise for improving the cleaning efficiency of spores. On the other hand, a clear improvement of the biofilm removal was observed when increasing the mean wall shear stress. The characterization of the foam and the interface phenomenons (using polarography, conductimetry, and bubble size analysis methods) indicated that mechanisms such as fluctuation in local wall shear stresses, or in the liquid film thickness between the bubbles and the steel wall induced by bubble passage, foam imbibition, and sweeping of the contamination within the liquid film could participate largely to the removal mechanisms. Finally, the life cycle assessment study demonstrated that foam flow cleaning could be a suitable technique to reduce water and energy consumption (7 and 8 times less, respectively) presenting less environmental impacts than CIP processes, with about 70%. Lastly, foam flow cleaning can be an alternative method, which can improve efficiency and reduce environmental impact. Additional activities conducted during the PhD period related to hygienic design are presented highlighting the role of the contaminants (spores and biofilms), the material (other than stainless steel) and the geometry (ducts or more complex design) in hygiene monitoring
Han, Guobin. "Influence des propriétés rhéologiques de surface sur la morphologie et la dynamique des mousses bidimensionnelles." Poitiers, 1996. http://www.theses.fr/1996POIT2382.
Full textJaudouin, Olivier. "Physico-chimie de matériaux à base d'élastomères modifiés hyperélastiques." Thesis, Montpellier 2, 2012. http://www.biu-montpellier.fr/florabium/jsp/nnt.jsp?nnt=2012MON20036.
Full textThe aim of this PhD work is to replace current gloves of gloveboxes used in nuclear area by elastomer discs which could take the shape of the arm of an operator and come back to their original shape when the arm is removed. The goal of the work is to design and study a material meeting the following specifications: at least 2 000 % strain at break, very high elastic properties, tear and radiation resistant. A bibliographic study showed that the most relevant materials are thermoplastic elastomers. As a consequence, two kinds of these materials were formulated. First ones are thermoplastic polyurethane elastomers. The influence of stoichiometric ratios and different chain extenders on mechanical properties was studied. These materials are too viscous to match the specifications but an interesting linear relation between flow stress and viscosity ratio was observed. Second ones are Styrene-Ethylene-Butylene-Styrene copolymers (SEBS). Studies on the influence of the process and incorporation of plasticizers, nanoparticules or polyurethane were carried out. It was highlighted that the process strongly influences mechanical properties and addition of nanoparticules or polyurethane can increase some of these properties. On the whole, the materials developed are very close to these of hyperelastic materials
Breul, Thierry. "Etude de l'influence des variables de formulation sur les propriétés moussantes des systèmes liquides polyphasés." Toulouse, INPT, 1992. http://www.theses.fr/1992INPT005G.
Full textYvrard, Jean-Philippe. "Expérimentation et modélisation du comportement mécanique du polystyrène expansé." Lille 1, 1998. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1998/50376-1998-431.pdf.
Full textBao, Jin-Biao. "Elaboration de polypropylène ou de polystyrène à l'aide du dioxyde de carbone supercritique : procédé – microstructure – propriétés mécaniques." Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL111N/document.
Full textIn this work, scCO2 induced foaming of PP or PS is systematically studied with emphasis on the relationship between process, microstructure and mechanical properties. The first part of the thesis deals with the toughening of iPP by scCO2 induced crystallization for the fine separation of rigid crystalline domains and soft amorphous ones in the polymer matrix. The highly oriented iPP with “shish-kebab” and “spherulite” are then used for CO2 foaming to investigate the effect of crystalline structure on the formation of cell nucleation and growth. In addition, the effect of the foaming conditions and the cell structural parameters of PS foams on the mechanical properties are studied systematically. PS foams with isotropic cell morphology and oriented cell one are prepared. Finally, a two-step depressurization batch process is developed to produce bi-modal cell structure PS foams by using scCO2 as the blowing agent. This unique cell structure with both small and large cells homogenously distributed throughout the entire volume of the foam sample might have particular properties
Yammine, Joumana. "Rhéologie des bétons fluides à hautes performances : relations entre formulations, propriétés rhéologiques, physico-chimie et propriétés mécaniques." Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2007. http://tel.archives-ouvertes.fr/tel-00482782.
Full textMauray, Alexis. "Etude des propriétés de transport de mousse dans des modèles de milieux poreux." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI120/document.
Full textIn enhanced oil recovery (EOR), foams are injected in porous media to improve oil recovery efficiency. The objective is to limit viscous fingering thanks to the high effective viscosity of the foam at low capillary number Ca. Foam is produced by the co-injection of a gas and a solution of surfactants. This thesis focuses on foam formation and transport mechanisms in model porous media using a heterogeneous micromodel made in NOA. Foam formation is studied using two different approaches. The first one consists in studying a co-injection of two fluids thanks to a jet flowing in the center of the system. This experiment shows that the less wetting fluids is dispersed in the other one when the capillary number is higher than 10-5. A second set of experiments is conducted by injected a pre-formed train of big bubbles in model a porous media. The bubbles divide until they reach a diameter of the order of to the pore size, for high enough capillary numbers Ca. Besides, we studied the transport properties of foam in similar model porous media. Direct measurements show that the pressure drop induces by the flow can be at Ca=10-6 as high as 3000 times the pressure corresponding to water injected at the same injection flow rate. This ratio decreases with capillary number. An analysis of the preferential paths by direct observations shows that, for low relative gas flow rate, only a few paths are active. However, an increase of the capillary number or if relative gas flow rate leads to a homogenization of the flow in the medium. Thanks to different simple models of straight or wavy channels, we measure that the pressure drop induced by a single bubble is in good agreement with Bretherton’s law, and scales as Ca2/3. However, in wavy channels the pressure drop due to a single bubble deviates from this prediction and exhibits a plateau at Ca lower than 10-4. In this regime, the motion of the bubble is usually intermittent. Finally, we focus on foam formation and transport properties in presence of oil. Our observations lead to the conclusion that for our setup and surfactant formulations, oil has a negligible influence
Stora, Éric. "Modélisation multi-échelle et simulations du comportement chimie-mécanique des matériaux cimentaires dégradés." Université de Marne-la-Vallée, 2007. http://www.theses.fr/2007MARN0369.
Full textEzbakhe, Hassan. "Caractéristiques thermiques et mécaniques de matériaux poreux utilisés comme isolants simples ou porteurs." Lyon 1, 1986. http://www.theses.fr/1986LYO10024.
Full textChevalier, François. "Propriétés techno-fonctionnelles et biologiques de la beta-lactoglobuline modifiée par la réaction de Maillard." Bordeaux 1, 2001. http://www.theses.fr/2001BOR12422.
Full textBenkabou, Rim. "Étude des propriétés nano-mécaniques d’un béton." Thesis, Reims, 2018. http://www.theses.fr/2018REIMS007/document.
Full textThis thesis aims at developing a numerical multiscale homogenization method for prediction of elasto-viscoplastic properties of a high performance concrete (HPC) where the microstructural heterogeneities are analyzed with the nanoindentation. The homogenization procedure was separated into two-levels according to the microstructure of the HPC: the matrix level composedof hydration products, clinker and fly-ash and the mortar level which accounts for large air porosity and aggregates. The elastoviscoplastic behavior of individual microstructural phases of the matrix are identified from nanoindentation data. An inverse method is applied by using the finite element simulation of the nanoindentaion tests combined with a numerical optimizationprocedure. The micromechanical results are then used as input parameters for numerical elasto-viscoplastic homogenization at microscale. The mortar level is analyzed with numerical homogenization by using the finite element simulation to predict the overall elasto-viscoplastic high performance concrete properties. The results are compared with macroscopic experimental and analytical results from the literature showing a good agreement. The procedure developed in this work gives promising results for the prediction of HPC properties and can be extended to other constitutive laws including damage. The last part of the thesis is dedicated to the experimental study of two concretes prepared with two different adjuvants
Pire, Myriam. "Caoutchouc naturel époxydé et réticulation par les acides dicarboxyliques : chimie, cinétique et propriétés mécaniques." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2011. http://pastel.archives-ouvertes.fr/pastel-00732940.
Full textMiquelard-Garnier, Guillaume. "Synthèse et propriétés mécaniques d'hydrogels polyélectrolytes modifiés par des groupements hydrophobes." Paris 6, 2007. https://pastel.archives-ouvertes.fr/tel-00343871.
Full textOrtiz, Aurélie. "Étude par simulation moléculaire de la flexibilité des matériaux nanoporeux : propriétés structurales, mécaniques et thermodynamiques." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2014. http://tel.archives-ouvertes.fr/tel-01053664.
Full textCuisinier, Olivier. "Comportement hydromécanique des sols gonflants compactés." Vandoeuvre-les-Nancy, INPL, 2002. https://tel.archives-ouvertes.fr/tel-00004524.
Full textThe use of compacted soils in engineering practice is very wide spread, especially in geotechnical and environmental engineering. These soils can be submitted to moisture variations, i. E. Suction changes, that induce volumetric deformations. The main objective of this thesis is to study the suction influence on the hydromechanical behaviour of a compacted swelling soil in the range of suction comprised between 0 and 300 MPa. For this purpose, two kinds of suction controlled oedometers, using the osmotic method or the salt solutions technique, were employed. The salt solutions oedometer were especially developed for this study. The samples were made with a compacted swelling material. The experimental study has shawn that the apparent preconsolidation stress reaches a constant value above a suction of 38. 9 MPa. The slope of the plastic compression curve had a maximum value under a suction of 4 MPa. These results seem to be related to the initial internal structure of the samples. Then the influence of complex hydromechanical stress paths was also investigated. It appeared that the results of the tests conducted on a swelling soil depended on the followed stress path even if a wetting is performed during a test. In the last part of this work, the test results were interpreted with the Barcelona Basic Model and Barcelona Expansive Model (BExM). The possibilities of bath models were compared. To interpret the test results with the BExM, it is necessary to conduct sorne additional tests that include a suction cycle and also a constant volume test with a suction controlled wetting. As a conclusion, two suction controlled experimental deviees were developed and validated in this study. With these deviees, the influence of structure and suction on the hydromechanical behaviour of a compacted swelling soils was characterised
Barzegari, Mohamad Reza. "Structure-flexural modulus relationships in polymeric structural foams." Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26347/26347.pdf.
Full textDecreus, Benjamin. "Étude de la précipitation dans les alliages Al-Li-Cu de troisième génération : relations entre microstructures et propriétés mécaniques." Grenoble INPG, 2010. http://www.theses.fr/2010INPG0020.
Full textThe aim ofthis work consists in understanding the micro structural evolutions oftwo AI-Li-Cu alloys of the 2000 series during heat treatments and to link the microstructures observed with subsequent mechanical properties. First class characterization techniques such as Small Angle X-Ray Scattering and Transmission Electron Microscopy have been used to identify precipitation sequences during heat treatments and to measure the growth kinetics of the main precipitates occurring in the two alloys. A model accounting precipitation growth during heat treatment has been proposed. Ln the meantime, the study of yield stress, plastic behaviour and gliding reversibility during heat treatment enabled to understand the influence of precipitation on mechanical properties and work hardening. Finally, the studyof short-transverse toughness and ofthe fracture modes evolution by tearing tests pointed out a strong influence of heat treatment duration on intergranular precipitation evolution
Fellah, Farid. "Microstructure et propriétés magnétiques et mécaniques du cobalt nanostructuré consolidé à partir de nanoparticules synthétisées par chimie douce." Paris 13, 2009. http://www.theses.fr/2009PA132019.
Full textNanostructured materials exhibit physical and mechanical properties significantly different from the corresponding bulk part. In this context, this work is a study of magnetic and mechanical properties of cobalt nanostructured materials. A bottom up approach, combining polyol process and either Hot Isostatic Pressing or Spark Plasma Sintering, was chosen to elaborate nanostructured materials. First, the synthesis of particles resulted in 50 and 240 mn cobalt nanoparticles with a faced centered cubic structure (fcc). Secondly, the consolidation gave mixture of fcc and hexagonal closed packed (hcp) materials with mean grains sized varying from 235 to 340 nm. Grains materials are observed to be subdivided by a lamellar structure corresponding to the fcc and hcp phases. The growth substructure seems to be dependant of the material density. Magnetic properties show an evolution with the grains size whereas mechanical properties show lamellar density dependence. In one hand we measured coercive fields characteristic of soft magnetic materials but still higher than amorphous materials. And in another hand, mechanical stresses reach 1200 MPa which are obviously better than amorphous materials. More over, the elongation to failure is still in a good range compared to nanocrystalline materials
Bourgain, Guillaume. "Caractérisation physicochimique d'un nouveau détergent dérivé de sucre : le décyl galactoside uronate de sodium : influence du décanol sur ses propriétés moussantes et mouillantes." Compiègne, 1996. http://www.theses.fr/1996COMPD899.
Full textBennani, Vincent. "Etude de la microstructure d'un alliage de titane coulé et usiné : relation avec les propriétés mécaniques : thèse." Nice, 2001. http://www.theses.fr/2001NICE7501.
Full textDame, Cécile. "Etude des relations entre la stabilité des mousses de décontamination nucléaire et leurs propriétés physico-chimiques." Aix-Marseille 3, 2006. http://www.theses.fr/2006AIX30012.
Full textThe LPAD (French Atomic Energy Commission) develops innovative processes in the frame of the future dismantling of nuclear facilities. Formulations were developed using high viscosified foams stabilized by biodegradable nonionic surfactants : alkyl polyglucosides and viscosifiers (xanthan gum), which allow us to increase the foam lifetime and thus contact time of chemical reactants with the facility walls. We have considered the relationships between physicochemical properties and foam stability through the exploration of the foam at three different scales: from the molecular range (micelles, surface tension and viscoelasticity), to the film and Plateau border range (XR reflectivity, surface shear viscosity) and to macroscopic range, meaning the whole foam (foaminess, liquid fraction and wall film thickness evolution). Finally, exploratory study is presented concerning simultaneous foam three scales characterisation by small angle neutron scattering
Sophie, Sacquin-Mora. "Représentations gros-grain pour la modélisation des protéines : Propriétés mécaniques et interactions." Habilitation à diriger des recherches, Université Paris-Diderot - Paris VII, 2011. http://tel.archives-ouvertes.fr/tel-00652917.
Full textBriceño-Ahumada, Zenaida Cenorina. "Propriétés rhéologiques et moussantes des phases lamellaire et éponge du système dodécylsulfate de sodium-hexanol-saumure." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS331.
Full textIn this thesis a study of the rheological and foaming properties of the lamellar and sponge phases of the SDS/hexanol/brine system was performed. Shear rate and temperature sweeps were done to analyze the rheology of the lamellar and sponge phases, adding frequency sweeps for the lamellar phase samples. Also, foamability and foam stability tests of foams made with these two phases were done. Sponge phase samples with membrane volume fractions phi ≥ 0.08 showed a Newtonian behavior, whereas in the less concentrated ones, phi 0.05 and 0.024, a change in viscosity was seen at shear rate values near to 1000 and 100 s ⁻¹, respectively. This change can be linked to a shear induced transition sponge to lamellar phase. Results indicate that temperature and the addition of the hydrosoluble polymer PEG affect the shear rate value at which this transition occurs. Lamellar phase samples with phi ≥ 0.10 presented a sharp increase in viscosity at intermediate shear rate values. The standard rheology technique together with Rheo-SAXS experiments allowed us to infer that there is a shear induced phase transition to vesicle phase. Rheo-SAXS data confirmed that the average interlamellar vesicle phase decreases by the effect of shear rate, and, when shear is stopped, the vesicle structure is relaxed and goes back to the lamellar phase after certain time. Foams made with lamellar phase samples showed a high stability and it was found that the time evolution of the bubble diameter follows a power law equation with exponents smaller than those reported for coarsening and Ostwald ripening. The small values of these exponents seem to be related with orientation defects of the liquid crystalline phase. On the opposite, the foams made with the sponge phase samples presented poor stability, as a possible consequence of the passages that form their structure that could facilitate coalescence of bubbles
Petit, Clémence. "Etude des propriétés mécaniques de matériaux cellulaires par la tomographie aux rayons X et par modélisation par éléments finis." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0130/document.
Full textCellular materials are highly porous systems for which two scales are mainly important: the mesostructure and the microstructure. The mesostructure corresponds to the architecture of the materials: distribution of solid phase “walls” and macroporosity and can be characterized by X-ray tomographic low resolution images. The link between the architecture of the materials and the mechanical properties has been frequently studied. The microstructure refers to the characteristics of the solid phase. Its microstructural features (presence of a secondary phase or of defects due to the sintering) can have a strong influence on the macroscopic properties. The aim of this work is to link the morphological and microstructural features of metallic and ceramic based cellular materials and their mechanical properties thanks to X-ray tomography and finite element modelling. A new method combining X-ray tomography at different resolutions, image processing and creation of finite element modelling enabled to take into account some microstuctural features of the cellular samples. Four different cellular materials were studied as model materials: aluminium foam fabricated by a liquid state process, cobalt periodic structures made by additive manufacturing, β-TCP porous samples fabricated by conventional sacrificial template processing route and hydroxyapatite/β-TCP composites made by additive manufacturing (robocasting). The metal based materials were provided by colleagues while the ceramic based porous materials were fabricated in the frame of the current study. For each type (metals or ceramics), a stochastic and a regular structure have been compared. For implementing the multiscale method developed in this work, the samples were firstly scanned in a so called “local” tomography mode, in which the specimen is placed close to the X-ray source. This allowed to reconstruct only the small irradiated part of the sample and to obtain a magnified image of a subregion. These images enable to observe some details which are not visible in lower resolution. Different image processing steps were performed to generate low resolution images including microstructural features imaged at high resolution. This was done by a series of thresholding and scaling of the high resolution images. The result of these processing steps was an image of the initial sample. Then, in situ mechanical tests were performed in the tomograph to follow the deformation of the sample at low resolution. The above mentioned initial images were used to produce finite element meshes. Special Java programs were adapted to create finite element input files from initial images and meshes. The initial images containing information about the solid phase, the images from the mechanical tests and the finite element models were combined to explain the mechanical behaviour of the sample by linking the experimental damage locations in the sample and the simulated stress concentration sites
Bérépion, Bastien. "Incidence de la composition chimique et des propriétés physico-chimiques des gommes en acacia sur leurs propriétés en émulsion." Le Havre, 2011. http://www.theses.fr/2011LEHA0013.
Full textAcacia gum is an exudate from Acacia senegal var senegal commonly used in food and pharmaceutical industry as emulsifier and stabilizer (E414). The aim of this thesis, in partnership with Allan & Robert, was to study the relationship between chemical composition, physic-chemical properties, functional properties and environmental conditions of acacia gums synthesis and harvest. At first, studying raw gums show the influence of geographic origin and post-harvest storage condition on the acacia gums chemical composition and physic-chemical properties. Then, we confirm the important role of AGP fraction in emulsions properties into correlating the AGP percent with the emulsifying properties, the aromatic amino acid proportion in the fraction with the emulsion stability and the aggregates negative effect on the emulsion properties. Furthermore, a relation appears between emulsions quality and protein percent in gums. Finally, we highlighted the atomization process influence on physic-chemical and functional properties of acacia gums
Assfeld-Lamaze, Christine. "Etude des relations entre les propriétés lubrifiantes et le comportement physico-chimique d'émulsions à base de tensioactifs nonioniques." Nancy 1, 1994. http://www.theses.fr/1994NAN10432.
Full textBalayssac, Jean-Paul. "Relations entre performances mécaniques, microstructure et durabilité des bétons." Toulouse, INSA, 1992. http://www.theses.fr/1992ISAT0010.
Full textItul, Anca. "Interactions entre organo-silanes et client : conséquences sur l'hydratation et les propriétés mécaniques." Phd thesis, Université de Bourgogne, 2010. http://tel.archives-ouvertes.fr/tel-00656843.
Full textSaikaly, Wahib. "Etude par microscopie électronique du rôle de chaque étape du traitement thermomécanique sur la précipitation dans les aciers dual-phase microalliés au titane." Aix-Marseille 3, 1999. http://www.theses.fr/1999AIX30095.
Full textGasser, Stéphane. "Etude des propriétés acoustiques et mécaniques d'un matériau métallique poreux modèle à base de sphères creuses de nickel." Phd thesis, Grenoble INPG, 2003. http://tel.archives-ouvertes.fr/tel-00004438.
Full textComparet, Cédric. "Etude des interactions entre les phases modèles représentatives d'un ciment Portland et des superplastifiants du béton." Dijon, 2004. http://www.theses.fr/2004DIJOS051.
Full textYang, Guang. "Structure and physical properties of chalcogenide glasses." Rennes 1, 2012. http://www.theses.fr/2012REN1S027.
Full textThis work aims at contributing to refine the structural properties of two simple glassy systems, AsₓSe₁₋ₓ and GeₓSe₁₋ₓ families. Although a lot of insightful research has been done on these glass models, their structural descriptions are still controversial. To achieve our goal, a large set of physical and structural properties was recorded on a same series of glassy samples for each family. The composition dependence of physical properties exhibit an extremum at = 2. 4 in AsxSe1-x glassy system. These results indicates a dramatic structural change at x = 0. 4, which evolves from a pyramidal network in Se-rich region and then transitions to a lower dimension structure containing an increasing number of 0-D molecular inclusions in As-rich region. Moreover, a series of physical properties throughout and above the glass transition, shows a double minimum at =2. 3 and =2. 5 with a local maximum at =2. 4. The observed trend is in agreement with the dimensionality of the network derived from structural data obtained by NMR. In binary GexSe1-x glasses, our results also indicates a dramatic structural change at x = 1/3. For the Ge-rich region, they do not support the tetrahedral model but strongly suggests that the Ge-rich glass network is closer to the GeSe crystalline phase structure. On the other hand, the viscosity of As₂Se₃ glass within the hot-zone region of the fiber drawing process was estimated using the actual temperature distribution and from standard continuum mechanics equations for a linear viscous material. Effect of ageing conditions (ageing in dark, in light and under load) on mechanical property of Te₂As₃Se₅ glass fibers has been investigated
Maldonado, Miguel. "Advances in estimation and control for flotation columns." Doctoral thesis, Université Laval, 2010. http://hdl.handle.net/20.500.11794/21919.
Full textHumbert, Séverine. "Influence de la topologie moléculaire et de la microstructure sur les propriétés mécaniques des Polyéthylènes." Lyon, INSA, 2009. http://theses.insa-lyon.fr/publication/2009ISAL0101/these.pdf.
Full textThe semi-crystalline polymers are widely used in fields as various as packaging, automotive, aeronautics. . . Because of their specific properties. Thus, the need to predict their viscoelastic and plastic behaviours with microstructural parameters is quite obvious. Due to its relatively simple structure which makes it a model material for semi-crystalline polymers, the Polyethylene has been and remains the most studied. However, there remain many unresolved issues, including the mechanical coupling between the amorphous and crystalline phases. Our work has been undertaken with a view to advancing knowledge on micro-mechanisms of deformation. In this aim, we have selected five polyethylenes of various molecular architectures. Then different heat treatments were carried out to modify their initial microstructure. We have been able to decorrelate the microstructure and the molecular topology. A wide campaign of microstructural and mechanical characterization (tensile tests, DMA, AFM, RX. . . ) has allowed to demonstrate the roles of two different scales on the mechanical behaviour: the scale of the lamella and the scale of the spherulites. Particular attention was paid on the stress transmitters (tie molecules, entanglements, interphase) present between the amorphous and crystalline phase. We have thus demonstrated their significant influence on micro-mechanisms of deformation. They play a role on the elastic and plastic properties much significant than it is generally reported in the literature
Le, Bail Nicolas. "Conception, synthèse par chimie douce et caractérisation de revêtements sol-gel hybrides multifonctionnels sur polycarbonate." Thesis, Ecully, Ecole centrale de Lyon, 2015. http://www.theses.fr/2015ECDL0040/document.
Full textThe polycarbonate is a widespread polymer material, highly appreciated for its low density, its transparency and its good mechanical properties. This material is used for divert applications (automotive, medical, optical...) and is very competitive in terms of quality and prices. However, it displays some weaknesses, essentially due to its poor abrasion and scratch resistance and its possible degradation under UV or hydrolysis. In this context, the PhD aim is to design and develop a new hybrid organic / inorganic protective coating with silica and zirconia based precursors prepared by the sol gel process, which allow a curing compatible with the polycarbonate's Tg (148°C). Here, it is discussed on the solutions retained to obtain a scratch resistant, hydrophobic and transparent coating. It is showed that, scratch resistant protective coatings can be deposited on pristine PC thanks to a performing hybrid organic / inorganic coating by modulating its bulk properties. Moreover, results demonstrate the key role played by a phenylsilane precursor in enhancing the adherence. Nanoindentation, scratch-test, NMR and FTIR analysis will be discussed
Wolff, Valérie. "Influence de l'ensimage sur les propriétés mécaniques de tissus de verre enduits de résine phénolique ou de latex." Lille 1, 1996. http://www.theses.fr/1996LIL10096.
Full textCappelin, Isabelle. "Synthèse de liants pouzzolaniques : application au traitement des sols fins argileux." Toulouse 3, 1992. http://www.theses.fr/1992TOU30280.
Full textDufaure, Nicolas. "Modification de polymères par la chimie supramoléculaire." Phd thesis, Paris 6, 2008. http://pastel.archives-ouvertes.fr/pastel-00539646.
Full textMasson, Eric. "Incidence du mode de séchage sur les caractéristiques physico-chimiques du bois de chêne de tonnellerie (Quercus petraea (Matt. ) Liebl. )." Nancy 1, 1999. http://www.theses.fr/1999NAN10302.
Full textPerez, Jean-Philippe. "Etude de l'hydratation des phases constitutives d'un ciment Portland et de la résistance mécanique des pâtes pures et mortiers : influence des trialcanolamines." Dijon, 2002. http://www.theses.fr/2002DIJOS012.
Full textKraiem, Omar. "Comportement mécanique d’une mousse fragile. Application aux emballages de transport de matières dangereuses." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLN028/document.
Full textDue to improvements in the manufacturing process that allow a better control of their microstructure, brittle foams are now part of the new efficient materials. New markets in the field of structural applications open up thanks to their excellent mechanical properties combined with light weight.In this study, a carbon foam with open cells has been studied in order to be used as shock absorber in packagings. Its compressive mechanical behavior has been characterized under various uniaxial and multiaxial loadings. The carbon foam yield surface and its evolution during loading have been identified. The main mechanical properties have been evaluated and some of them have been correlated with those predicted by the Gibson and Ashby micromechanical model. The mechanisms of deformation and the energy absorption have been studied using post-mortem observations by scanning electron microscopy (SEM) and X-Ray microtomography.The Deshpande and Fleck model (DF) has been adopted and slightly modified to model the compressive multiaxial behavior of the carbon foam. The latter is considered as an homogeneous continuum medium. The constitutive equations have been implemented in the finite element code LS-DYNA via a Umat routine. The model parameters have been identified and the model estimations validated on available triaxial tests as well as on crushing tests made on micro-structures. Numerical simulations are relevant on predicting the global macroscopic behavior. Nevertheless, the mechanical model needs to be improved to better account for some phenomena not currently described
Binda, Nathalie. "Modification de surface du mica muscovite en vue de son incorporation dans une matrice polypropylène." Montpellier 2, 1994. http://www.theses.fr/1994MON20034.
Full textBadaire, Stéphane. "Etude de suspensions et de fibres de nanatubes de carbone." Bordeaux 1, 2005. http://www.theses.fr/2005BOR12951.
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