Дисертації з теми "Procédés de composites"
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Taillet, Brice. "Procédés alternatifs pour l'élaboration de matériaux composites à matrice céramique." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0203/document.
The opening of the civil aviation market to ceramic matrix composite materials requires the development of new methods of producing compatible with the production rates and manufacturing costs of the sector.For this purpose, experimental work was conducted to develop a silicon oxynitride matrix (Si2N2O) by combustion synthesis (or SHS), from reactive powders. In recent years, Si2N2O has emerged as a promising new high-temperature ceramic material, characterized by not only good mechanical properties, but also by a higher oxidation resistance than silicon carbide. The underlying basis of SHS relies on the ability of highly exothermic reactions to be self-sustaining and, therefore, energetically efficient. Powders are first milled, dispersed and stabilized in aqueous media, and then impregnated into a fibrous preform composed of the latest generation of silicon carbide fibers (Hi-Nicalon S). SHS reaction is then carried out in a reactor specially designed and dedicated to this study. Particular attention was focused on the optimization of experimental parameters for the synthesis of a Si2N2O based matrix. Silicon metal in a mixture with silica powder was combusted under pressurized nitrogen gas into silicon oxynitride. The pressure and the temperature rise rate were the principal parameters for the composition and microstructure of the matrix. These parameters have been the subject of extensive experimental work to reach a homogeneous matrix with a very high formation rate for silicon oxynitride (more than 90wt%) and with a level of residual porosity lower than 10%. This work was completed by the calculation of the physical properties of the matrix, by the mechanical characterization of the composite material, and finally by a temperature aging test under moist air
Cazaux, Guillaume. "Faisabilité des procédés LCM pour l'élaboration de composites renfort continu à matrice thermoplastique polyamide." Thesis, Le Havre, 2016. http://www.theses.fr/2016LEHA0010/document.
The present work is a contribution to the thermoplastic composites manufacturing by a non-reactive Liquid Composite Molding process for the automotive industry. The thesis was carried out by the « ANR TAPAS » project (Thermoplastic Process for Automotive Composite Structure) and was focused on the elaboration of continious-fiber reinforced composites plates injected with a high-fluidity polyamide 6,6 (PA 6,6) by the Resin Transfer Molding process. The first goal was focused on increasing injection rates through the study of the in-plane permeability of unidirectional (UD) glass fiber fabrics with high mechanical modulus (HM). Experiments and modelling results showed that the permeability of these UD has been enhanced by modifying specific structural parameters of their architecture. The analytical model developped and used is based on a flow distribution according two differents scales of porosity : in and inter-yarns. The second part of the work was focused on the understanding of phenomenas that take place at the interface created between glass fiber and the matrix during the impregnation step. The wettability and adhesion of molten PA 6,6 dropped on a glass substrate is studied at different processing temperature. The last part introduce the thermoplastic composite plates elaborated by RTM-TP process. The optimum operating conditions as well as preforms saturation and mechanical properties are also studied and discussed
Magnant, Jérôme. "Composites fibreux denses à matrice céramique autocicatrisante élaborés par des procédés hybrides." Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14105/document.
The fabrication of multidirectional continuous carbon fibers reinforced dense self healing Ceramic Matrix Composites by new short time hybrid processes was studied. The processes developed are based, first, on the deposition of fiber interphase and coating by chemical vapor infiltration, next, on the introduction of ceramic powders into the fibrous preform by Slurry Impregnation and, finally, on the densification of the composite by liquid-phase Spark Plasma Sintering (SPS) or by Reactive Melt Infiltration of silicon (RMI).The homogeneous introduction of the ceramic particles into the multidirectional fiber preforms was realized by slurry impregnation from highly concentrated (> 32 %vol.) and well dispersed aqueous colloid suspensions. The densification of the composites by spark plasma sintering was possible with a short (< 5 minutes) dwelling period in temperature. The chemical degradation of the carbon fibers during the fabrication was prevented by adapting the sintering pressure cycle to inhibit gas evolution inside the system. The composites elaborated are dense. The fully densification of the composites by RMI was realised by carefully controlling the impregnation parameters to avoid to entrap some gaseous species inside the fiber preforms. Our carbon fiber reinforced ceramic matrix composites processed by Spark Plasma Sintering or Reactive Melt Infiltration have a damageable mechanical behaviour with a room temperature bending stress at failure around 300 MPa and have shown their ability to self-healing in oxidizing conditions. Compared to the CMC processed by CVI, the composites processed with a final consolidation step by RMI are fully dense and have a similar room temperature tensile test behaviour with an ultimate tensile stress around 220 MPa
Waris, Marc. "Mise en œuvre, instrumentation, validation et modélisation d’un système d’injection RTM pour la fabrication de structures composites de hautes performances." Thesis, Saint-Etienne, EMSE, 2012. http://www.theses.fr/2012EMSE0661/document.
A significant growth in production and consumption of composite materials can be seen recently; growth reinforced by the new European standards, aimed at reducing CO2 emissions by the year 2020.The producing of complex parts can cause many difficulties for manufacturing because of their geometries and / or their constituents (using of various materials). For example, dry zones or geometric distortion formation. The origins of these difficulties are often related to a lack of knowledge and control of the reinforcement's impregnation phases and material curing.Improving the robustness of the processes demands a detailed knowledge of physical phenomena that occur during the producing. For this, we studied the composite materials production through the implementation of a laboratory demonstrator in the project LCM Smart. This pilot injection was used to validate instrumentation solutions, from innovative sensors (OFS) developed in partnership with the optical laboratory Hubert Curien. The application of this instrumentation in the context of RTM process monitoring in the development of simple parts has demonstrated the capabilities of OFS to control physical characteristics of the part (the flow front, temperature, residual strain and curing degree). The comparison of the measured characteristics with numerical simulations carried out in collaboration with ESI showed a good correlation.Finally, instrumentation has demonstrated the capacity of composite tool made by HexTool to minimize the residual stresses due to the tool/part interaction
Madigou, Véronique. "Relations procédés-microtexture-propriétés dans des composites à matrice Si3 N4 renforcés SiC." Pau, 1991. http://www.theses.fr/1991PAUU3024.
Haddad, Madjid. "Étude de l'impact des défauts d'usinage des structures composites par détourage sur leur comportement mécanique." Toulouse 3, 2013. http://thesesups.ups-tlse.fr/2179/.
This thesis focuses on problems encountered during the trimming of composites materials using continuous fibers. The thesis is divided into three main parts. In the first part, the machinability of two composites materials made of carbon fiber and epoxy matrix at standard cutting speed and at high cutting speed is investigated. Surface damages induced are analyzed using surface roughness tester and the scanning electronic microscope. The impact of cutting conditions, machining processes (i. E. , cutting tool, abrasive diamond cutter, abrasive water jet machining), and nature of composite materials on the form and size of the surface defects are studied. The second part of the thesis concerns the study of the dust generated during trimming in terms of number of particles present in air and masses. The effect of tool geometry, composite material and cutting conditions on the generated dust is studied. The last part is dedicated to the study of the relationship between machining processes, surface defects and mechanical behaviour of composite parts in quasi-static and dynamic environment. Specimens designed for quasi static tests are instrumented on the surface for the digital images correlations and high speed cameras to monitor the damage generation and progression during the tests. The dynamic tests are instrumented by an infrared camera in order to measure the thermal dissipation during the damaging phases of specimens
Kim, Moo Sun. "Optimisation des structures composites en intégrant les paramètres de fabrication." Saint-Etienne, EMSE, 2007. http://www.theses.fr/2007EMSE0029.
In this study, optimization of mechanical properties of a composite material product manufactured by compression molding process was performed by considering the changes of fiber states. Fiber states, which changes by the compression molding process, are fiber volume fraction and fiber orientation. These fiber states lose their initial properties and show non-homogeneous and anisotropic properties due to the pressure and velocity field generated during compression process. To predict the fiber states changes during the compression molding process, fiber separation phenomenon and orientation were numerically considered by coupling them with flow analysis computed by CVFEM. Based on the fiber states information, the mechanical properties of chopped fiber composite were computed. Then they were applied to the plate type structure analysis. In the gross, numerical analysis of process and structure were coupled. In addition, the optimization of structural design and process condition was performed. Structural thickness and precharge location and dimension were considered as the design variables. At first, the Complex method was implemented for thickness optimization. The optimization results of two cases, where the compression process was considered in one case and homogeneous and isotropic material were considered in the other, are compared. To resolve the precharge location and dimension optimization problem, genetic algorithm was implemented. The constraints of design vectors and the characteristic of optimization problem divide search space into feasible search space and unfeasible search space. To handle the constraints of optimization problem, the penalty function method and modified repair algorithm were applied. By applying them to the test function, optimization procedures for these two methods were compared. The suggested techniques were applied to symmetric rectangular plate, car-hood type structure and arbitrary and asymmetric shape structure and the optimization results were compared
Khazma, Mahmoud. "Contribution à l’optimisation de composites cimentaires à base de coproduits du lin : procédés de traitement de la matière végétale et de la matrice ; impact de ces procédés sur les propriétés des composites élaborés." Amiens, 2008. http://www.theses.fr/2008AMIE0125.
This work is done in the processes and materials engineering group of the Laboratory of innovating technologies of the University of Picardy Jules Verne. The main goal of this work is the valorization of vegetables’ byproducts, specifically the use of flax shives as aggregates in cementitious matrix. Flax shives, like all lignocellulosic materials, are known by their high hydrophilic properties. During concrete confection, shives absorb mixing and inhibit the cement hydration. To optimize their use, these shives must be hydorphobisated. Treated shives are characterized by SEM, FTIR, water absorption…. Then, the impact of these treatments on the hydration of cement matrix and the physico-chemicals characteristics of composites are quantified and evaluated. The second way explored in this thesis is the matrix treatment. These treatments are done using molecules extracted from the biomass. The elaborated composites show a high competitive properties in comparison with composites prepared with commercial vegetables aggregates
Davila, Montano Yves Angel. "Etude multi-échelle du couplage matériau-procédé pour l'identification et la modélisation des variabilités au sein d'une structure composite." Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30009/document.
One of the major challenges related to the use of composite materials in structural applications is the difficulty to predict the effect of their inherent variabilities on the mechanical behaviour for such materials. The structural properties do not only depend on the fabrication process, but also depend on the raw materials and design considerations. The major goal of this thesis is the introduction of geometrical variabilities into a finite element (FE) model starting from the hypothesis that geometrical variations are not completely randomly distributed, but they maintain a spatial continuous evolution. To guarantee that the input parameters of the FE model are based on the reality of the material, the identification and quantification of the variability distributions together with their spatial evolutions are performed during the fabrication of CFRP composite plates. These plates have a 16 ply quasi-isotropic stratification and are cured in autoclave. Among the identified and quantified variability sources, the study of the in plane fibre misalignments and the evolution of the ply thickness variations has conducted to the proposition of mathematical representations of the spatial evolution of these variables based on the material reality. These mathematical representations are used to recreate different sets of virtual composites structures maintaining dispersion values similar to the real plates. Finally, the virtual structures are analysed in the FE model to evaluate the impact of such geometrical and material variabilities on the mechanical properties of the final structure
Drapier, Sylvain. "Modélisation multi-échelle des structures composites, comportement en compression et lien avec les procédés." Habilitation à diriger des recherches, Université Jean Monnet - Saint-Etienne, 2002. http://tel.archives-ouvertes.fr/tel-00562396.
Venault, de Bourleuf Antoine. "Elaboration d'hydrogels composites chitosane/charbon actif à visée cicatrisante par procédés d'inversion de phase." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20048/document.
Chitosan/Activated carbon composite hydrogels were prepared by phase separation induced by (i) immersing the polymeric solution in a non-solvent solution (wet process) and (ii) exposing the polymeric solution to non-solvent vapors (VIPS process). The multi-scale characterization approach (SAXS, WAXS, MEBE, storage modulus, diffusion tests) did not evidence any influence of the contact mode on the functional properties of the gels. Final structures are homogeneous, porous and amorphous. They are suitable to constitute the wound dressings layer in contact with eschar-like sores. An innovative chitosan gelation model was developed coupling mass transfers, heat transfers and chemical reactions. It permitted to forecast gelation times and concentration profiles. Simulation also corroborated the non-influence of the process on the final structuring of the matrices, analyzing transfers throughout the elaboration
Dkier, Mohamed. "Etude rhéocinétique de polyamides HT : Application à la mise en forme de matériaux composites par des procédés réactifs." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI080/document.
The main objective of this work has been to develop an experimental investigation making it possible to monitor, as well as achieve a deeper understanding of the structural evolution of high temperature polyamide (PA-HT) as a thermoplastic-based composite matrix. Various formulations of prepolymer with chain extender (CA) were studied at different stoechiometry ratios and temperatures with or without continuous glass fibers. Furthermore, the interest of such a study is twofold: i) optimization of the time required for injection of the reactive system into the mold in which a fibrous reinforcement is predisposed. Thereby, the control of the conversion amount of such thermoplastic system is a critical parameter for a better control of impregnation. ii) a better understanding of structure-property relationships of the obtained thermoplastic composites. Since that the reaction kinetic was demonstrated very fast to be monitored at short times by usual technics at high temperatures above 275°C), the chemo-rheological evolutions were firstly studied ex-situ by coupling rheology with fast FTIR and dielectric spectroscopy (DRS). The ultimate purpose was to correlate the viscosity and the conversion rate in the mold. Then, a rheokinetic modeling approach was performed in order to be able to predict the evolution of the viscosity in particular at very short times (less than 2 minutes which the conversion reaches about 80%). In this work, hybrid process coupling “Reactive Extrusion”and “Resin Transfer Molding” machine (T-ERTM) equipped with an instrumented mold was designed and developed. Secondly, the hybrid process coupling “Reactive Extrusion” and “Resin Transfer Molding” machine (TP-ERTM) with an “instrumented mold” was developed with specific dielectric sensors in order to in-situ track viscosity and the extent of the reaction. The in-situ results corroborate the ex-situ ones aforementioned. Overall, a processing window was obtained for each reactive system to ensure a good preform impregnation for the manufacturing of complex and continuous glass fiber-reinforced parts. Herein, the structure/physical/mechanical/morphological properties of the obtained composites have been established
Bohr, Élaine. "Étude des échanges thermiques dans la fabrication des composites par les procédés d'injection sur renfort." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0017/MQ53559.pdf.
Zhang, Ga. "Etudes des procédés d'élaboration et des propriétés des revêtements de PEEK et de ses composites." Besançon, 2005. http://www.theses.fr/2005BESA2060.
In recent years, driven by economic and ecologic reasons, thermoplastic coatings have been very attractive for industrial applications. The PEEK (polyetheretherketone) is a polymer with excellent mechanic properties, in particular a good tribological performance. Its tribological behaviour, especially wear resistance properties, can be improved when it is reinforced by the micro-fillers in forms of particles or fibres. Some previous studies show that the pure PEEK coating exhibits good mechanical properties. However, homogenizing the reinforcements in PEEK matrix seems very difficult in the elaboration process. Therefore, it's difficult to obtain a homogeneous PEEK based composite coating using the conventional coating methods. The objective of this work is thus to realize PEEK based coatings (pure and composite) with good mechanical performances. With regard to this aim, four following directs of work have been carried out. Firstly, a new method for the elaboration of PEEK based coatings was developed using screen printing technique. Secondly, the crystallization behaviour of amorphous PEEK coating was studied and this crystallization behaviour was correlated with coating mechanical properties. Thirdly, the frictional performances of PEEK based coatings were examined; the frictional mechanism was discussed. Finally, a study on the feasibility of densifying by laser the PEEK based coatings was performed
Waris, Marc. "Mise en œuvre, instrumentation, validation et modélisation d'un système d'injection RTM pour la fabrication de structures composites de hautes performances." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2012. http://tel.archives-ouvertes.fr/tel-00849584.
Andriamananjara, Koloina. "Modélisation numérique des procédés LCM à l’échelle des milieux homogènes équivalents en cours de déformation – intégration de la pression capillaire lors de l’infusion et équilibrage post-infusion." Thesis, Lyon, 2019. https://tel.archives-ouvertes.fr/tel-02921453.
The LRI process consists in impregnating a fibrous preform through its thickness, under the pressure gradient created by pulling the vacuum. This out-of-autoclave process was developed to reduce manufacturing costs and ensure proper filling of large parts; hence the increasing interest of the aeronautical industry in this technique. This work, within the framework of the Hexcel-Mines Saint-Etienne Chair, aims to establish a predictive numerical tool to simulate the main physical phenomena occurring during the process at macroscale. In order to properly model the complex and multi-scale phenomena during the infusion process, a numerical approach based on finite-element method is developed to model the capillary effects during the filling stage and to model the post-filling stage. Capillary effects are represented by a capillar stress tensor acting at the bi-fluid interface of the flow modelled by Darcy's equations. By generating a pressure jump, it requires a local pressure enrichment of the elements crossed by the fluid front. The results are validated with a convergence analysis and a confrontation with experimental data. The model is adapted to the mesoscale to simulate the flow through the tows. A first approach of post-filling stage modeling is proposed, which describes the interaction between the preform deformation and the resin flow after the filling. Modeling this stage allows to study the influence of fluid-solid coupling on the final part regarding the dimensional tolerances, and to predict the evolution of the fibre volume fraction which determines the part mechanical properties. The first simulation tests reveal a high potential for industrial simulators
Rahme, Pierre. "Contribution à l'étude de l'effet des procédés de perçage-alésage sur l'apparition du délaminage dans les structures composites épaisses." Toulouse 3, 2008. http://thesesups.ups-tlse.fr/2154/.
The composite materials, including carbon fibers, are increasingly used in aeronautics. The assembly of the various structural parts and the covering requires the creation of the rivets and bolts housing. The drilling by removing material from those houses panels thick carbon / epoxy causing defects at the entry, on the wall of the hole and at the exit of the plate. These various defects diminish the quality of the hole and the failure strength of the material. The identification and the minimization of these defects are the subject of this study. A real-time observation of the initiation and the propagation of defects is firstly done by using fast-shoot and infrared cameras. Microscopic observations were also conducted on full field drillings. Among the observed defects, delamination at the hole exit, considered as the major defect, is directly related to the tool thrust force (FZ). To minimize these defects, the study has focused on modeling of this thrust force and its link with the delamination of the machined laminate. Thus, in a first time, delamination critical thrust force when drilling orthotropic material is modeled analytically. Several hypothesis of loading and boundary conditions are developed in order to adjust the model to the desired tool geometry. This analytical model is validated by a numerical modeling (finite elements method) and an experimental study (punching tests). In a second step, a phenomenological model linking drilling thrust force to cut conditions is developed. This simple model offers the advantage of being used in drilling or reaming and to be adaptable to the chosen tool geometry. Finally, both parties are used to deduce the critical cutting conditions on delamination. This adaptive method to the tool geometry allows to determine, for a given material, the cutting conditions that minimize delamination during drilling and reaming operations. The leading study contributes to the optimization of the drilling-reaming process of the composite materials, both in terms of the cutting tools design that in terms of steering the process
Gantois, Renaud. "Contribution à la modélisation de l'écoulement de résine dans les procédés de moulage des composites par voie liquide." Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1652/.
Liquid Composite Molding (LCM) is more and more used in industry for its ability to produce complex and large parts at low cost. However, this process needs a special care to anticipate properly the impregnation of the fibrous reinforcement, which remains a challenging task important to achieve. This work is divided into an experimental and a numerical study. It aims to model the resin flow through the fibrous reinforcement occurring during the mold filling stage. An experimental setup has been designed to measure both plane and transverse permeabilities of the reinforcement. The numerical study is focused on the simulation of the flow at macroscopic and microscopic scales. At macro scale, our main contribution is the coupling between BEM and Level Set methods, which has been achieved for both 2D and 3D problems. At micro scale, a stationary BEM solver has been developed to evaluate the transverse permeability of a 2D fibrous microstructure
Mayer, Philippe. "Contribution à la définition du processus de conception et de réalisation de pièces produitsà hautes caractéristiques spécifiques." Thesis, Paris, ENSAM, 2017. http://www.theses.fr/2017ENAM0003/document.
The objective of this work is to contribute to the comprehension of a new composite forming process which name is EPITHER. This forming process was created to produce massive composites parts used for structural applications in automotive and aeronautics industries. Two patents have been deposed in 2011 and in 2015/2016.There are three steps in the forming process EPITHER: winding a preform in order to maximize and optimize the anisotropy of the composite considering the mechanical specifications of the final part, forming the preform by a thermoforming step, add morphological properties in a last step.The Phd deals with three major research axis: setting up an experimental study, the comprehension of the consolidation steps and a study of the consolidation parameters
Rothan, Alexandre. "Etude rhéologique de formulations thermodurcissables, pour la modélisation de procédés de type SMC." Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAE003/document.
The research presented is divided into 2 independents chapters: - the 1st one focuses on the rheological study of a fibreless formulation for SMC. This study allows us to write constitutive equations of the formulation. These equations are in turn implemented in a numerical simulation program, in order to predict the forces generated during a compression experiment. These simulated data are eventually compared with experimental data obtained during compression.- the 2nd chapter concerns the study of a rare rheological behaviour: the negative rheopexy. The viscosity of the sample depends on its shear history, in a very different way than a thixotropic sample’s viscosity would. This rheological behaviour is very component sensitive, and results from the interactions between 4 components. As soon as one of them is missing, the negative rheopexy disappears. The mixture studied is constituted of products traditionally used for the production of SMC
Hajj, Nemr El. "Contribution à la conception et à l'élaboration d'une âme multicouche multifonctionnelle agrosourcée pour panneau sandwich : étude expérimentale et modélisation." Amiens, 2010. http://www.theses.fr/2010AMIE0107.
Since the 90s, new composite materials have emerged in the industrial domain : environmental constraints and new regulations on the recycling of composite materials have pushed the industry to develop new materials from renewable resources. The objective of this study is to acquire knowledge of resources and tools for the design and implementation of a 100% agro-sourced core of sandwich structure satisfying mechanical, thermal and acoustic features. This work consists of developing methods for elaborating self-bonding composites, agro-linking composites and thermopressed plates, thereby promoting the products of lesser quality flax plant (flax-tow and shives). The interaction method-product is more than ever true in the case of this new family of agro-sourced composites. Experimental elaboration development and characterization have been established. They aim to establish a link between raw materials (anas and flax tow), the manufacturing process and the desired properties (mechanical, thermal and acoustic). Regarding the modelling tools, the relevance of various micromechanical and thermal models was evaluated. These models must obviously take into account the mechanical, thermal and acoustic properties of components as well as the geometric and structural parameters (ratio of reinforcements on length-diameter – fiber orientation). This step is difficult due to the complexity of materials and the variability of the components. However, it is necessary if there is need to provide, in the future, a tool for decision support in selecting an optimal combination of acoustic, thermal and mechanical features. This thesis has allowed proposing several multi-performance materials with very interesting mechanical, acoustic and thermal performances with good prospects
Chaouki, Hicham. "Modélisation du comportement des composites thermoplastiques à renforts continus dans les procédés de mise en forme." Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/27682/27682.pdf.
Salem, Mohamed Medhat. "Etude expérimentale et numérique des défauts de bouclage et de glissement lors de la mise en forme de composites structuraux à base de fibres synthétiques et végétales." Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0117.
Composites with fibrous reinforcements are extensively used in advanced industries such as aeronautics or the automotive industry because of their higher mechanical property/mass ratio compared to that of metals. Their complex shape forming presents major scientific challenges, particularly for composites with woven reinforcements. In fact, woven reinforcements are subject to defects when shaped on complex geometries with high curvature. Some of these defects have already been the subject of several studies, while others, such as the tow buckling and sliding defects, have not been fully explored yet. At this moment, simulation codes cannot accurately predict the occurrence and development of tow buckling and sliding defects during the shape forming of woven reinforcements. One of the reasons is the lack of knowledge about the origin and kinematics of these defects. This thesis work proposes to bring more understanding on these defects through an experimental and numerical approach. Concerning the tow buckling defect, the influence of tensions in the tows network, the nature of the reinforcement, the reinforcement weave and the dimensions of the tows have been studied. For the sliding defect, the influence of the type of reinforcement, tensions in the tows, the reinforcement weave and the orientation of the tows in the reinforcement have been explored. These results open up perspectives for improving the quality of composite parts
Dufour, Dabadie Isabelle. "Contribution à l'évolution des procédés de contrôle non destructif par capteurs inductifs : application au cas des matériaux composites carbone." Paris 11, 1993. http://www.theses.fr/1993PA112123.
Hoppe, Sandrine. "Contribution à l'étude de deux procédés d'élaboration de matériaux composites présentant des propriétés d'absorption aux ondes hyperfréquences." Vandoeuvre-les-Nancy, INPL, 1995. http://docnum.univ-lorraine.fr/public/INPL_T_1995_HOPPE_S.pdf.
Zaidani, Mouna. "Modélisation numérique de la mise en oeuvre des matériaux composites par les procédés d'infusion sous membrane flexible." Le Havre, 2012. http://www.theses.fr/2012LEHA0018.
In the infusion process, it is important to take into account the reinforcement deformation as well as the resin flow. Moreover, the analysis of the process physics clearly shows the existence of a hydro-mechanical coupling between two phenomena. In this work , a numerical tool to model the hydro-mechanical coupling of unsaturated deformable fibrous medium, considering a void formation and compression/tow saturation model is presented. The case study of two phase defromable medium requires an analyse of the pore scale phenomena and an up-scaling method on a Representative Volume (REV) of the local mass conservation equations, the reinforcement compressibility and the resin flow occur simultaneously ans there is thus a mutula influence between the two solid and liquid phases. It is important to simulate the infusion process by calculating the maximum height infused by the resin, the final height of the part, the infusion time and the content and entrapped air un the final part. In the simulation code, a void formation model is integrated considering two different flows in the macropore and the micropore, respectively, the viscous flow ans the capillary wicking. The influence of fibrous medium deformation on the fiber tow saturation and void formation during infusion is presented too
Sublet, Marcq Julie. "Membranes et procédés pour l’abattement de la teneur en dioxyde de carbone dans les fumées." Rouen, 2007. http://www.theses.fr/2007ROUES052.
The present work brings an other point of view concerning the CO2 separation from flue gases by using membrane technology. The study of the permeation properties of the commercial copolymers Pebax® as well as the analysis of the gas separation performances of composite membranes by means of mathematical modelling are presented. The aim was to modified the best Pebax® grade with a simple technique to improve the material properties for CO2/N2 separation. Composite membranes made of a thin layer of Pebax® supported by a porous substrate were next designed and analysed. Potential performances concerning CO2 postcombustion capture were calculated. The blend of Pebax® 1657 with polyethylene glycol gives PCO2 = 127. 9 Barrers and alphaCO2/N2 = 79. 9. Modellings based on a crossflow permeator showed that the membrane process could be competitive for CO2 postcombustion capture under certain operating conditions (CO2 concentration, pressure and temperature)
Villière, Maxime. "Analyse des transferts de chaleur couplés à la saturation pendant l’imprégnation d’un renfort fibreux : application aux procédés LCM." Nantes, 2013. http://archive.bu.univ-nantes.fr/pollux/show.action?id=30bc4fa5-7b2e-407e-a4eb-83977ffd0527.
Transportation industries, especially aeronautics and automotive industries, are facing more than ever energy-saving issues, which imply weight reduction of structures. Within this context, composite materials appear to be appropriate candidates, due to their outstanding “strength to weight” ratio. Liquid Composite Molding (LCM) and particularly Resin Transfer Molding (RTM) are becoming increasingly important for a wide range of industrial applications involving complex structural parts. The quality of LCM products strongly depends on the impregnation of the fiber preform during the mold-filling stage. During this step, a partially saturated zone emerges in the flow, and induces consequently the formation of porosities, which drastically affect mechanical performances. This study presents an original approach in which heat transfers are used to quantify the saturation profile. In a first step, the effective thermal conductivity of a model composite material have been measured by several methods. A homogenization methodology based on asymptotic expansion has been performed at dual-scale in order to predict the thermal properties of the composite as a function of saturation. Several heat flux sensors and thermocouples were integrated in an experimental bench, which allows the injection of a model fluid into a textile preform. Finally, an alternative numerical approach is proposed by modeling a multi-phase flow, proving the feasibility of identifying the relative permeabilities of each phase through thermal analysis
Celle, Pierre. "Couplage fluide/milieu poreux en grandes déformations pour la modélisation des procédés d'élaboration par infusion." Saint-Etienne, EMSE, 2006. http://www.theses.fr/2006EMSE0029.
An overall model for the study of a non isothermal fluid flow across a highly compressible porous medium is presented and applied for the study of dry composite manufacturing processes by infusion (Liquid Resin Infusion-LRI and Resin Film Infusion-RFI) in order to predict the thickness and the porosity of the final structure. The model developed includes a modified Beaver-Schaffman-Joseph condition to couple flow across and outside the porous medium. An ALE formulation of the liquid flow across the deformable porous medium in which finite strains are accounted is coupled with an updated Lagrangian scheme for the solid behaviour. Finally, thermo-chemical models are employed to account for the resin reticulation. Numerical tools have been developed and combined for the simulation of LRI and RFI processes. Numerical results have been compared with experimental test
Alarie, Nicolas. "Conception d’un fuselage en composites pour le Symphony SA-160." Mémoire, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/7724.
Dereims, Arnaud. "simulation industrielle des procédés d’élaboration de pièces composites par infusion de résine : couplage fluide / solide poreux très faiblement perméable en grandes déformations." Thesis, Saint-Etienne, EMSE, 2013. http://www.theses.fr/2013EMSE0699/document.
Composite manufacturing processes by resin infusion, despite their many benefits, struggle to establish themselves in the industrial production phases due to difficulties to control them. So, in partnership with ESI Group, a comprehensive model for the simulation of these processes is developed at the ENSM-SE since the pioneering work of P. Celle.Our work focuses on the generalization of this model to handle complex industrial cases in three dimensions, as well as its extension to “post-infusion” flow simulation. The approach is based on three domains decomposition of the field (Distribution medium, impregnated preforms, dry preforms) consisting in coupling a Stokes flow in the distribution medium with a Darcy flow in the preforms. In addition, the mutual influence of the resin on the preforms and of the preforms deformation on the permeability is considered, through Terzaghi’s law and models expressing the permeability as a function of the fibre fraction, data only accessible with a 3D coupled mechanical approach. Finally, the process is divided into three phases: initial compression of dry preforms, filling and “post-infusion”. The numerical methods developed in this work, apply to real infusion cases often discarded in recent publications, involving very low permeability (~10-15 m²), thin distribution medium (~ 1 mm) and complex geometries (3D curved).This innovative approach has been implemented in an industrial simulation code (ProFlotTM), validated analytically over test cases and experimentally over industrial cases in the European project INFUCOMP
Tran, Thang. "Micro-poro-mécanique : détermination des coefficients de Biot et de la perméabilité des milieux fibreux." Artois, 2009. http://www.theses.fr/2009ARTO0201.
Processing composites often involves either the compression of preimpregnated fiber reinforcements or the flow of a viscous liquid within fibrous materials. The process considerably influences the quality of composite materials. In this work the hydro-mechanical coupling is studied. The micromechanical approach is applied to estimate the compression moduli and the Biot tensor of UD fiber reinforcements with single and multi scale of porosity. Based on the mathematical analogy between the mechanics, fluid mechanics and heat transfer, the permeability and thermal conductivity tensors are obtained by a straightforward calculation from micromechanics. The study of the UD fiber reinforcement with single scale of porosity is carried out thanks to the analysis of the microstructure. The distribution of the fibers in the cross section is discribed by the probability density function of the Gamma distribution. To verify the theoretical results, experimental tests are carried out. The Biot coefficients are measured by the triaxial machine, traditionally used for granular medium, for isotropic and transversely isotropic fiber reinforcements
Guo, Xueping. "Etude des procédés d'élaboration et caractérisation des revêtements de bronze et de ses composites préparés par projection à froid." Phd thesis, Université de Technologie de Belfort-Montbeliard, 2009. http://tel.archives-ouvertes.fr/tel-00603634.
Ouabbas, Yamina. "Procédés mécaniques d'élaboration à sec de particules composites à propriétés d'usage contrôlées. Caractérisation et stabilité d'un gel de silice." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2008. http://tel.archives-ouvertes.fr/tel-00276411.
Dans ce travail trois différents dispositifs, l'Hybridizer (enrobage par impact mécanique élevé), le Cyclomix (mélangeur par cisaillement élevé) et le Turbula, ont été utilisés. Pour comparer ces techniques, un couple modèle de poudres ayant des propriétés très différentes a été alors choisi. À cette fin, une poudre de gel de silice (GS, 55 µm) hydrophile a été traitée avec de fines particules de stéarate de magnésium (StMg, 5 µm) hydrophobe dans des proportions massiques variables.
La morphologie de surface des particules de gel de silice enrobées à été examinée par la microscopie électronique à balayage environnemental (MEBE). L'utilisation de l'AFM en mode contraste de phase mode Tapping a permis de mettre en évidence la présence très localisé du StMg à la surface du gel de silice. Les forces d'adhésion entre du StMg collé à une pointe AFM et les différentes poudres, ont été mesurées en mode contact. L'effet du traitement mécanique sur l'affinité vis-à-vis de l'eau des particules de GS a été évalué par le test de la goutte d'eau posée et la DVS. La modification de la coulabilité du gel de silice après traitement a été analysée par un voluménomètre.
L'étude de la stabilité des particules de gel de silice enrobées a montré l'effet de l'humidité relative sur le vieillissement de l'enrobage. Ce phénomène est accompagné par une diminution du volume spécifique des pores du GS. Un mécanisme de diffusion du StMg depuis la surface externe des particules de GS vers la surface interne des pores est proposé.
Lachaud, Jean. "Modélisation physico-chimique de l'ablation de matériaux composites en carbone." Bordeaux 1, 2006. http://www.theses.fr/2006BOR13291.
Carbon-based composites are used in extreme conditions: Tokamaks, re-entry bodies, nozzle throats. Their walls undergo a surface recession, called ablation, mainly due to some gasification phenomena (oxidation or even sublimation). This work is a contribution to the improvement of the understanding of the near-wall material/environment interaction and to its modeling. Some original gasification experiments have been carried out, modeled, and quantitatively analyzed; a complex multiscale behavior of the materials is observed through their average recession velocity and a surface roughness onset mainly caused by their heterogeneous anisotropic structure. In order to explain these observations, a multiscale modeling strategy has been set up; it follows the characteristic scales of the composites: nanoscopic (carbon texture), microscopic (fiber, inter-fiber matrix), mesoscopic (yarn, inter-yarn matrix), and macroscopic (homogenized composite) scales. The proposed models notably integrate the local recession of the wall, the heterogeneous gasification reactions, and mass transfer. A numerical simulation tool, based on Monte-Carlo Random Walks, has been implemented, validated, and used to solve these models. Under some numerically validated hypotheses, an analytical homogenization provides the effective behavior of the composites as a function of the intrinsic reactivity of their components. The results of these phenomenological models have been validated by comparison to the laboratory experiments and applied for the analysis of actual applications. Physics-based criterions are made available for the choice or the fabrication of ideal materials
Dumas, Angela. "Élaboration de nouveaux procédés de synthèse et caractérisation de talcs sub-microniques : de la recherche fondamentale vers des applications industrielles." Toulouse 3, 2013. http://thesesups.ups-tlse.fr/3999/.
This thesis takes part of the general process of innovation in the domain of composite materials. The funding by the ANR NANOTALC project allowed significant progress in the process of production of new talc-like mineral nanofillers. The talc synthesis process has been revised in order to achieve compatibility with industrial requirements in terms of performance and efficiency. This new process replaces the previous ones since it saves time, leads to a 100% talc product having a high crystallinity, in the respect of few principles of the green chemistry. The crystal-chemistry characterization of the new synthetic talc shows new spectral signatures related to nanoscale dimensions, which allow also understanding of some until now unexplained behavior of natural powders. The synthetic talc derived from this new process differs from its natural counterpart in its submicron size, its chemical and mineral purity and also in its hydrophilic character, which is enhanced by the abundance of particle edges bearing silanol functions. This thesis also describes the various techniques tested to optimize this process and provides a new technical solution for the implementation of the synthesis on a semi-industrial scale
Prioux, Manon. "Elaboration de nouvelles EBCs par des procédés en voie liquide du type électrophorèse." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30198.
Ceramic Matrix Composites (CMCs) due to their high thermal stability and mechanical properties are the promising materials to replace nickel superalloys in turbine blades or rings. These parts are subjected to stresses at very high temperatures, up to 1500 °C on the surface, which induce significant damage, such as corrosion of the CMC. To limit this degradation, coatings protecting the substrate against corrosion have to be developed. In the framework of this thesis, the objective is to develop an EBC by electrophoresis allowing to deposit architectures of controlled thickness layers of yttrium disilicate and yttrium monosilicate, limiting the heat treatment steps and with a process able to be transferred on shaped parts. Electrophoresis (EPD) is a method based on the migration under the effect of an electric field of charged species, such as particles dispersed in a liquid, . The mechanisms leading to electrophoretic deposition are complex and a rigorous control of many parameters is necessary. The parameters involved in EPD are both linked to the medium (electrical conductivity, viscosity, nature of migrating species, surface charge and stability) and to the process (applied electric field, deposition duration and cell configuration). The first part of this work was to study the influence of these parameters on the coatings and their microstructures. The zeta potential, the electrophoretic mobility and the electrical conductivity of the suspensions studied appear to be first-order parameters, influencing both the formation of coatings: kinetics and growth mechanisms, but also their microstructures: density and homogeneity. The use of low voltages promotes the formation of more compact coatings, and a compaction effect is also observed over the long deposition times. The other part of the thesis work focused on optimizing the architecture of the complete system by adjusting both the electrical parameters, the sintering conditions, but also the composition of the suspensions, in order to characterize the coatings in working conditions. It has been shown that a stack of 3 layers of ytterbium disilicate with an intermediate consolidation step at 200 ° C between the layers was necessary to reach the target thickness of 30m, after a heat treatment at 1350°C for 5h with a temperature rise ramp of 300 ° C / h and 100° C/h down. This type of system has led to encouraging results in terms of corrosion behavior with only 3% cracking after 500h at 800 ° C under 50kPa of water. Finally, the complete architecture developed, by adding the layer of yttrium monosilicate on the surface, meets the required criteria: the EBC is adherent, dense, homogeneous and covering
Nadeau, Nathalie. "Modélisation mathématique et numérique d'un front de densification lors de l'élaboration d'un matériau composite carbone/carbone par un procédé par caléfaction (CVI)." Bordeaux 1, 2004. http://www.theses.fr/2004BOR12937.
Pontoreau, Maël. "Fabrication de matériaux composites innovants base argent renforcés par des nanotubes de carbone par différents procédés de mise en forme." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0074.
The enhancement of mechanical, thermal and electrical properties of silver could lead to an increase of the life cycle of electrical contacts. In this framework, carbon nanotubes (CNT) have been identified as a potential reinforcement thanks to its high mechanical, thermal and electrical properties. The development of metal matrix composite Ag/CNT is challenging regarding the CNT nanometric size. Indeed, CNT are nanomaterials which are entangled in its powder form. The work of this PhD has led to the implementation of two processes for the synthesis of a Ag/CNT composite powders in which the CNTs are homogeneously dispersed. From these powders, composite materials were densified and then extruded. The analysis of the microstructure as well as the physical properties of these composite materials related the change in properties to the volume percentage and orientation of the CNTs within the Ag matrix. Among other things, the significant increase in hardness and the conservation of thermal and electrical properties observed for these composite materials could increase the life cycle of the contact materials and find a short-term application in the industrial world
Pons, Audrey. "Simulation numérique de la montée capillaire en espace confiné, en vue de l’application à des procédés d’élaboration de matériaux composites par imprégnation non-réactive ou réactive." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0701/document.
The development of ceramic matrix composites (CMCs) to replace certain metal components ininternal hot parts of aircraft engines is an active research field for the aeronautical industry. Theseadvanced components may be manufactured with a fluid processing called ReactiveMelt Infiltration(RMI). The densification step is the capillary rise of a molten metal such as silicon within a wovenpreform. The molten metal can react with the previously introduced ceramic powder and lead to arefractory matrix. The competition between capillary rise and the reaction between molten siliconand introduced carbon powder has to be managed. The ambition is to prevent choking off effectsand closed pores created by preferential paths. Simulations of two-phase flows at macroscopic scaleare undertaken with a homemade code developed in SAFRAN whereas simulations of two-phaseflows atmicroscopic scale were undertaken with CFD code Thétis (developed at I2M, Bordeaux). Anexperimental methodology for analysis of reactive or not reactive capillary impregnation in granularmedia is described
Blais, Maxime. "Modélisation et suivi du procédé par infusion de résine sur une nouvelle génération de renforts structuraux pour l’aéronautique." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEM003/document.
This study deals with the manufacturing by infusion of a new high performance fibrous reinforcement solution developed for LCM (Liquid Composite Molding) composite materials manufacturing processes. Combining simulations with experimentations, the aim of this work is to understand and control the process parameters in order to develop accurate simulation tools. Involving specific experimental plan and protocols combined with in-situ monitoring technologies this study points out the physics and length scales challenging the process simulation. The numerical strategy considered in this works is based on a strong coupling between a Stokes and Darcy model undergoing large strains and where interfaces are represented and managed by a Level-Set method. At the process scale, the fluid mechanics problem describes the resin flow through the distribution medium and then through fibrous preforms assimilated to porous medium. A key feature of our approach is the fluid-solid interaction leading to couple a fluid/porous flow with a non-linear solid mechanic problem. The interaction phenomenon due to the resin flow in the orthotropic highly compressible preform is based on both Terzaghi’s law and explicit relations expressing permeability as function of porosity. Some numerical simulations are presented and compared to the experimental characterizations. The results point out the the first necessity to work on the permeability comprehension, definition and characterization. Applied to the specific reinforcements of the study, the representation of the complex local flows and their homogenization through this single permeability notion can also be questionable
Sallit, Imad. "Conception et réalisation d'un tribomètre à haute température : application à l'étude du frottement et de l'usure dans des procédés de mise en forme." Compiègne, 2000. http://www.theses.fr/2000COMP1287.
Wang, Peng. "Étude numérique et expérimentale de procédé d'élaboration des matériaux composites par infusion de résine." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2010. http://tel.archives-ouvertes.fr/tel-00566276.
Novichenko, Denis. "Fabrication par projection laset et caractérisation des pièces composites à base d'acier et carbure de titane." Ecole nationale d'ingénieurs (Saint-Etienne), 2011. http://www.theses.fr/2011ENISE008.
Theoretical and experimental data are reported in the thesis which leads to concrete recommendations in the field of direct manufacturing of parts from metal matrix composites based of steel and titanium carbide by laser cladding. Numerical simulation of gas flow and powder injection is carried out to define the optimal parameters for the powder particles. Analysis of the influence of the process parameters (laser power, scanning speed, powder feeding rate, deposition strategy) on geometrical and technological characteristics is performed to improve process efficiency and productivity. Brightness temperature in the working zone is analyzed under various conditions by pyrometer and infrared camera to control the material deposition process. Structure and properties of the laser-fabricated composite materials, particularities of the interaction between the reinforcement phase and the metal matrix are examined
Hautefeuille, Alexandre. "Couplage écoulement-déformation des renforts fibreux dans les procédés de mise en oeuvre des composites structuraux : Étude expérimentale, modélisation et contrôle." Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0047.
For the purpose of lightening structures, the transport industry has, for several years, been moving towards the production of large composite parts. The use of manufacturing processes with a strong hydromechanical coupling is essential to meet the growing needs for reduced cycle times. A key step in the process is the consolidation of the pre-impregnated fabric during composite processing. This step consists in complete the impregnation of the fluid in the fibrous reinforcement by transverse compression of the prepreg. The latter can generate a fluid flow over long distances (for example in the case of the I/C-RTM process). The use of high viscosity resins (sometimes above 10 Pa.s) coupled with high compression rates can generate a flow with the capacity to deform the fibrous architecture. The coupling between flow and induced deformations is addressed in this thesis. The objectives are to identify, quantify and control the mechanisms involved during the coupling of the flow and the deformation of the reinforcement. The development of specific experimental allowed to identify a mechanical signature, and then to localize the phenomenon of fibre washout on a large flat part. A model has been developed to integrate these induced deformations into the calculation of the fluid pressure field during the consolidation of the composite material. The flow resistance offered by the fibrous reinforcement is linked to the intra-pli friction. The development of a measurement bench allowed to quantify this resistance. Finally, the balance between the viscous drag and the friction forces is modelled to anticipate flow-induced in-plane deformations. This model results in the control of consolidation by driving the compression speed
Hijazi, Nibal. "Développement de composites nanostructurés à base de biopolyesters et de nanoparticules de chitosane générées par des procédés assistés par CO2 supercritique." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2014. http://www.theses.fr/2014EMAC0016/document.
In a logic of eco-design and sustainable development, many works aim to study the bio-sourced polymers. Among these studies, a promising concept consists in structuring materials at micro and nanoscales while enhancing some of their properties, the objective being the creation of original materials with improved functional properties and performance. In this context, particular attention has been paid to the use of supercritical carbon dioxide (sc-CO2). Its ability to dissolve into many polymers in large quantities and thus to change their properties (viscosity, interfacial tension, ...), can improve both the composite material and its manufacturing process. This project focuses on the development of nanostructured biopolymers and addresses two main issues: (1) the synthesis of biopolymer nanoparticles (in this case, chitosan), and (2) the development of nanostructured biopolymers. The first step consisted in designing and developing new processing methods to generate biopolymer nanoparticles, using sc-CO2 as antisolvent agent or as dissolving and atomizing agent. For the second step, poly (lactic acid) PLA and poly (hydroxybutyric-co-hydroxyvaleric acid) PHBV based composite films were prepared by a hot-melt process by twin-screw extrusion of the nanoparticles and the matrix. Thermal, molecular and structural analysis, as well as morphological and particle size distribution studies allowed a good characterization of the biocomposite films
Puech, Laurent. "Développement de composites polypropylène renforcés par des fibres de chanvre pour application automobile." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT144.
Due to the necessity to find alternatives to fossil resources and to reduce the environmental impacts of human activity, a major research effort is currently ongoing in order to develop and increase the use of biobased products from renewable resources, such as natural fibers, in the design of industrial parts. However, many scientific and technological hurdles have yet to be removed so as to promote these products before we can reliably and durably use these fibers in a demanding technical context as in automotive sector. Thus, improving the quality of the interface between natural fibers and polymer matrix is a major challenge, since it constitutes a condition for satisfying the required mechanical performances, such as stiffness, tensile or impact strengths. In this context, the thesis objective was to develop short hemp fibers with controlled and targeted surface properties. Surface-functionalization solutions have been developed, to be used by industrial processes, with the aim of incorporating these fibers in a polypropylene (PP) matrix. Therefore, hemp fibers have been treated according to various functionalization strategies including the use of grafted polypropylene maleic anhydride (PP-g-MA), organosilanes, an amino acid, isocyanates and a polyurethane. Two treatments processes, with low environmental impact, were compared: the direct spraying of functionalization molecules on fibers and reactive extrusion incorporation of these molecules. Reactive extrusion treatments were more efficient than those performed by spraying in the case of PP-g-MA. Three functionalization lanes have been found to be relevant regarding the mechanical properties targeted: i) using PP-g-MA alone in reactive extrusion; ii) spraying-functionalization of an aminosilane or of an amino acid coupled with the incorporation of PP-g-MA into the reactive extrusion. Based on the development of experimental means and specific analyzes, the study of the impact behavior of biocomposites has shown that hemp fiber reinforced composites allow to absorb more energy than PP / glass composites (at identical reinforcing volume rate) for a similar crack length. Also, a finite element modeling of the impact behavior of the studied composites is propounded
Dereims, Arnaud. "simulation industrielle des procédés d'élaboration de pièces composites par infusion de résine : couplage fluide / solide poreux très faiblement perméable en grandes déformations." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2013. http://tel.archives-ouvertes.fr/tel-00933928.
Chabanon, Elodie. "Contacteurs à membranes composites et contacteurs microporeux pour procédés gaz-liquide intensifiés de captage du CO2 en post-combustion : expérimentation et modélisation." Phd thesis, École Nationale Supérieure des Mines de Paris, 2011. http://pastel.archives-ouvertes.fr/pastel-00677145.
Chabanon, Élodie. "Contacteurs à membranes composites et contacteurs microporeux pour procédés gaz-liquide intensifiés de captage du CO2 en post-combustion : expérimentation et modélisation." Paris, ENMP, 2011. http://www.theses.fr/2011ENMP0061.
The decrease of the CO2 anthropogenic emissions is one of the main aims of the 21st century. Different processes are developed in order to capture CO2, but gas-liquid absorption in packed columns is considered as the reference postcombustion technology. Membrane contactors, which could potentially decrease by a factor 2 to 10 the size of the absorption units due to an increased interfacial area (1000 to 5000 m2. M-3 ), a so-called intensification effect, have been investigated in this study. Two kind of hollow fibers are studied: microporous and composite membranes (i. E. A dense polymeric skin coated on a porous support). In a first part, a series of experiments is reported to evaluate the influence of some geometric and operating parameters on the process capture performances and on the mass transfer characteristics. Results obtained on short time scale experiments are in agreement to the literature results. Even though a dense skin layer on a porous support generates an additional resistance to the mass transfer, a dedicated study carried out on long time scale (several hundreds hours) show for the first time that mass transfer performances of composite fibers can be similar to microporous unwetted membranes. Moreover, the wetting resistance of the composite fibers compared to microporous hollow fibers (PP and PTFE) is clearly demonstrated. In a second part, a comparative study of different mathematical models with increasing complexity is carried out. One parameter is used to fit the experimental results: the membrane mass transfer coefficient (km). Km values obtained through curve fits are in the range of data reported in the literature (10-2 to 10-5 m. S-1). However, the assumption of a km effective value which would depend of the operating conditions is addressed and discussed. This approach is different from the studies reported in the literature which generally postulates a single value for a given membrane material. Under these conditions, the composite membrane interest, which shows a constant and probably predictable value of the membrane mass transfer coefficient due to their wetting resistance, seems to be promising to intensify the gas-liquid absorption process in CO2 postcombustion capture