Tesi sul tema "Fibres textiles – Propriétés acoustiques"
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Luu, Hoang Tuan. "Modélisation multi-échelle de la dissipation acoustique dans des textiles techniques faits de fibres naturelles". Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1135/document.
Testo completoThis research project was inscribed in an eco-conception approach for architected materials with high acoustic potential. In this research project, we are interested particularly in the description of dissipation and propagation phenomena of sound waves in a fibrous medium by using multi-scale and multi-physics approaches. In this work, we determine the transport and acoustic properties of fiber media based on the description of geometry at their local scale. The fiber media consist of asclepias fibers which are typically vegetable fibers adopting a long hollow cylinder. To solve this problem, the methodology consists of 4 principle steps below: (i) Characterize and model the geometry of fiber medium; (ii) Calculate the transport parameters and acoustic properties of reconstructed fiber medium; (iii) Validate the results of the transport and acoustic properties by comparing with experimental measurements; (iv) Evaluate the evolution of transport parameters as function of geometrical parameters at the local scale. For the geometrical reconstruction, isotropic model of straight lines (Poisson processes) and angular orientation tensor were used. They allow representing of principle characteristics influencing the transport and acoustic properties of material at macroscopic scale. The resolutions of principal problems governing the acoustic behavior at the macroscopic scale were then performed by using the numerical homogenization method. We firstly demonstrate that the developed method allows predicting of absorption behavior of a random fiber medium based on only their geometrical characteristic description (porosity, fibers radius, angular orientation distribution) without adjustment coefficient, and the validated by experimental measurements. Secondly, based on the reconstruction method, one can systematically study the whole transport phenomena on a wide range of porosity and angular orientation in order to provide the laws which can be applied by other user on a wide range of real fiber media. Finally, we verify more particular the hypothesis that a fibrous material can be described by a mean diameter value of their fibers, this work allows identifying the limit of this approach and their application conditions when a fiber medium is constituted of a large distribution of fiber diameters or bimodal
Tran, Quang Vu. "Locally heterogeneous three-dimensional fibrous media : Representative elementary volumes and calculation of acoustic properties". Electronic Thesis or Diss., Université Gustave Eiffel, 2023. http://www.theses.fr/2023UEFL2081.
Testo completoThis thesis explores the complex relationship between the structures, acoustic properties, and manufacturing processes of non-woven fiber materials. Two families of composite fibrous media, derived from recycled textile fibers and recycled PET fibers, were studied, offering a diversity of polydispersity. Through microstructural characterization and numerical homogenization, this research identified key parameters associated with transport and sound absorption properties.The volume-weighted mean diameter Dv and inverse volume weighted mean diameter Div were found to be essential geometric descriptors. They explain acoustic behaviors at different frequencies, revealing that viscous and thermal exchanges occur through the widest channels of the microstructure at low frequencies; while at high frequencies, the acoustic signature is influenced by the entire microstructure, including the smallest constrictions.The original contributions of this research include (1) the development of Representative Elementary Volumes (REVs) for polydisperse fibrous media; (2) solving an optimization problem based on the degree of polydispersity; (3) and proposing an experimental technique to estimate transport properties at high frequencies.In summary, this thesis offers promising perspectives for understanding and optimizing the acoustic properties of polydisperse fibrous media while identifying crucial microstructural descriptors for these complex materials
Hallal, Ali. "Modélisation analytique généralisée des propriétés élastiques des composites textiles". Versailles-St Quentin en Yvelines, 2013. http://www.theses.fr/2013VERS0004.
Testo completoThe use of textile composites has increased recently in advanced industries to replace traditional composites and laminates. The prediction of elastic properties of textile composites presents an important step to understand the mechanical behavior of these materials. The objective of this thesis is to propose a reliable analytical model benefits from analytical methods advantageous against numerical methods. The proposed generalized model has been applied to all kinds of textile composites, where it yields very good results especially for the Young's modulus and shear plane. The thesis consists is a thesis by articles/publications. The thesis consists of eight chapters: Coordinating chapter, six chapters correspond to six publications and a general conclusion
Pac, Marie Jose. "Les surfaces textiles aux échelles micro, meso et macroscopiques : propriétés thermiques et tribologiques". Mulhouse, 2001. http://www.theses.fr/2001MULH0644.
Testo completoBrinkert, Luc. "Fibres creuses d'ultrafiltration : propriétés mécaniques et contrôle en ligne sur site de filage". Mulhouse, 1992. http://www.theses.fr/1992MULH0247.
Testo completoAdolphe, Dominique. "Contribution à l'étude de certaines propriétés physiques et hydrauliques de géotextiles". Mulhouse, 1990. http://www.theses.fr/1990MULH0140.
Testo completoSaïhi, Douha. "Modification de surface des fibres textiles par greffage chimique : Synthèse et caractérisation". Lille 1, 2003. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2003/50376-2003-297.pdf.
Testo completoSeurin, Marie-José. "Contribution à l'étude de propriétés statiques de polymères mésomorphes". Nice, 1985. http://www.theses.fr/1985NICE4061.
Testo completoVu, Thi Hong Khanh. "Etude de l'influence de la structure et de la texture des microfibres de PET sur leurs propriétés tinctoriales". Mulhouse, 1997. http://www.theses.fr/1997MULH0474.
Testo completoFreyburger, Jean-Marie. "Développement d'une méthodologie et d'un appareillage destinés au contrôle mécanique des textiles linéaires soumis à des sollicitations rapides". Mulhouse, 1990. http://www.theses.fr/1990MULH0141.
Testo completoBigaud, David. "Description géométrique pour la caractérisation mécanique multi-échelles de matériaux composites à renforts textiles 2D et 3D". Lyon 1, 1997. http://www.theses.fr/1997LYO10223.
Testo completoWu, Yueming. "Evaluation des caractéristiques physique des étoffes par méthodes classiques et kes : études de corrélations". Mulhouse, 1992. http://www.theses.fr/1992MULH0218.
Testo completoMsahli, Slah. "Etude du potentiel textile des fibre d'agave americana L". Mulhouse, 2002. http://www.theses.fr/2002MULH0691.
Testo completoBertheux, Brigitte. "Etude mécanique de la compression de flocons de fibres : application à la mesure du "degré d'ouverture"". Mulhouse, 1989. http://www.theses.fr/1989MULH0103.
Testo completoHuilier, Hervé. "Apport de propriétés thermorégulantes à un tissu pour le prêt-à-porter par modifications physico-chimiques de la surface des fibres : application au polyester et à la laine". Besançon, 2003. http://www.theses.fr/2003BESA2065.
Testo completoResearch is being carried out to find the necessary steps to manufacturing a wool/polyester thermoregulating fabric. The perfecting of such a fabric requires that the phase-changing materials (PCM), which are micro-encapsulated at the surface of the textile fibres, can be flxed. The micro-encapsulation of the PCM is do ne by spray-drying method Alternating between formulation parameters makes it possible to manufacture micro-capsules that have much smaller diameters than those of the wool and PET fibres <5 microns). The physical properties of the walls give the micro-capsules extra resistance to treatments that wear down fabrics. Wooi and PET are both sensitive to UV, which penetrate the fabrics mostly by the radicalar photolysis of the amide and ester. The fixing of the micro-capsules to the surface of the fibres is done by co-polymerising an acrytic cross-linking agent with the micro-capsules, the wool and PET fibres by UV radiation at 254 nm. The binder photopolymerisation, in which the kinetic is influenced by the photonic intensity and the atmosphere, can be carried out in one second under air. The validity of the procedure has been tested in an industrial context. Thus, the fabric manufactured in this way has enthalpic properties of about 2 KJ. M-2, and it can be dyed, and dried up to 130 DC. Treatments at higher temperatures lead to partialloss of the fabric's climatic properties by fragilizing the wall of capsules. The capsules'walls is fragilized above its glass step transition The procedure is relatively polyvalent, and fixing the micro-capsules to different properties (i. E. Cosmétic, pharmaceutic. . . ) is possible
Brites, Sanches Salvado Luisa Rita. "Les Non tissés utilisés en hygiène : étude des relations entre les processus technologiques, la structures et les propriétés". Mulhouse, 2002. http://www.theses.fr/2002MULH0684.
Testo completoMadrolle, François. "Etude du comportement mécanique des matériaux textiles soumis à des sollicitations rapides". Mulhouse, 1995. http://www.theses.fr/1995MULH0368.
Testo completoBal, Kheireddine. "Etude du comportement hydraulique de textiles techniques de type fourrure ou aquafourrure : caractérisation des propriétés de perméabilité et de rétention". Mulhouse, 1991. http://www.theses.fr/1991MULH0195.
Testo completoNotin, Laure. "Étude fondamentale de l'élaboration et des propriétés de fibres de chitosane dans le cadre d'une problématique biologique". Lyon 1, 2006. http://www.theses.fr/2006LYO10038.
Testo completoDreyer, Claude. "Contribution à la modélisation de l'influence des caractéristiques des fibres de laine peignée sur les propriétés des textiles linéaires". Mulhouse, 1994. http://www.theses.fr/1994MULH0442.
Testo completoIndelicato, Giuliana. "Modèles mécaniques de réseaux de fibres 2D et de textiles". Thesis, Vandoeuvre-les-Nancy, INPL, 2008. http://www.theses.fr/2008INPL009N/document.
Testo completoIn this work, we discuss three basic problems related to the mechanical behavior of textile materials. First, we extend the model of Wang and Pipkin for textiles, described as networks of inextensible fibers with resistance to shear and bending, to a model in which resistance to twist of the individual fibers is taken into account, by including torsion contributions in the elastic stored energy. As an example, we study the behaviour of a cylindrical shell made of helical fibers. Second, we study how the geometry of the weave pattern affects the symmetry properties of the deformation energy of a woven fabric. For networks made by two families of fibers, four basic types of weave patterns are possible, depending on the angle between the fibers and on their material properties. The symmetry properties of the pattern determine the material symmetry group of the network, under which the stored energy is invariant. In this context, we derive representations for the deformation energy of a woven fabric that are invariant under the symmetry group of the network, and discuss the relation of the resulting group invariants with the curvature of the fibers. Third, we develop a model for textiles viewed as surfaces with microstructure, using a modification of the classical Cosserat model for shells, in which the microstructure accounts for the undulations of the threads at the microscopic scale. Describing the threads as Euler's elastica, we derive an explicit expression for the microscopic elastic energy that allows to set up a simple model for the macroscopic mechanical behavior of textiles
Eve, Sophie. "Comportement à la prise et propriétés mécaniques de matériaux composites à base de plâtre". Caen, 2003. http://www.theses.fr/2003CAEN2068.
Testo completoMagniez, Labalette Carole. "Nouveaux textiles à performances au feu et à tenue à la chaleur améliorées". Lille 1, 2002. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2002/50376-2002-77.pdf.
Testo completoOmrani, Fatma. "Caractérisation de la variabilité des propriétés mécaniques aux échelles fils, renforts et composites à base de lin". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10085/document.
Testo completoThis work focuses on understanding the mechanical properties of flax-based composites. First of all, a multi-scale characterization is carried out for oriented fabric with different types of yarns, structures and treatments. Parameters such as the weaving process and the existence of treatments like desizing and drying has a strong impact on the mechanical properties. Furthermore, the results shows a high variability of the mechanical properties at the yarn scale which decreases significantly at the fabric and composite equivalent properties with the synthetic fibres based composites. Secondly, the thesis focused on the mechanical properties of randomly oriented preforms known as nonwovens. The mechanical characterizations of flax fibre nonwoven are carried out with tensile, bending tests in the dry form. Then, forming tests of the non-woven preforms are performed with different geometries. Based on this experimental approach, a characterization protocol is established to identify and quantify their formability behavior. New phenomena such the variation of local density and the slippage of fibres network are observed for this type of reinforcement. The forming behavior depends strongly on the punch geometry, blank-holder, the area density and direction of the preform
Magno, Massimo. "Modèle mécanique du comportement de structures souples aux échelles mésoscopique et macroscopique : application aux matériaux fibreux". Mulhouse, 1999. http://www.theses.fr/1999MULH0554.
Testo completoCherif, Zine Eddine. "Caractérisation et optimisation d’un pré-imprégné industriel fibre lin/résine époxy pour les matériaux composites". Caen, 2013. http://www.theses.fr/2013CAEN2004.
Testo completoThis thesis focuses on the characterization and optimization of a prepreg based on epoxy resin and flax fibres. The reinforcement consists of fabrics made by twisted flax yarn. The composites were manufactured by two methods: hot platen press and autoclave chamber. Each material was tested using tensile tests to determine its mechanical properties (elastic and at break). Sorption properties were studied by immersion aging tests. Finally, the damping capacity of the flax/epoxy composite was determined from vibration tests of free beams and was compared with carbon/epoxy, glass/epoxy and kevlar/epoxy composites. A systematic study of the influence of the prepreg manufacturing parameters has been performed. We have studied the effect of the type of reinforcement (woven or quasi-unidirectional), the weaving parameters (yarn diameter, filling rate) and the influence of various textile pretreatments (applied to yarn or fabric). Some models are proposed to overcome the rate of porosity on the mechanical properties as well as on the sorption properties. The aim of this work is to identify the main properties of a range of flax/epoxy prepregs with woven reinforcement, and to establish optimal manufacturing conditions to optimize their performances
Bhouri, Naoufel. "Comportement thermodynamique et dimensionnel des matériaux textiles soumis à des variations des conditions climatiques". Thesis, Nancy 1, 2009. http://www.theses.fr/2009NAN10120/document.
Testo completoThe 2D deformation of bleached plain weave and Jersey cotton ready to wear clothing was measured during adsorption and desorption cycles. The strain along warp and weft directions and the shear deformation were evaluated by image correlation process. The dimensional variations are explained by geometrical consideration of the structure at microscopic (fibers scale) and macroscopic levels (yarns scale). Indeed, the reaction between water vapor molecules and material enlightens two steps. At first, the swelling fibers fill the micro pores inside the yarns. Then, the yarns swell and push on their neighbors to fill up the macro pores and cause the macroscopic swelling of the overall structure. During the desorption phase, the fibers shrink to create a free space inside the plain weave structure that will be relaxed to find its initial state. The shear deformation is related to the cohesion by twist between cotton fibers. The ironing generates flattened yarns and increases their friction which amplifies the deformation during the first adsorption cycle. However, this effect is cancelled at the end of the first adsorption / desorption cycle with no memory effect of the ironing process. These results are confirmed by comparison between sorption isotherms of ironed and not ironed plain weave samples. A comparison between the sorption capacity of Jersey and yarn made of the same structure shows that the geometric form decreases the sorption capacity of jersey especially at high humidity. Then knitting infects the swelling of yarns and decreases their sorption capacity
Hammi, Tarik. "Étude de méthodes de mesures et réalisation d'un banc de test pour l'évaluation des propriétés électrostatiques des textiles". Lille 1, 2005. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2005/50376-2005-Hammi.pdf.
Testo completoMuller, Didier. "Influence des caractéristiques physico-chimiques de la fibre de polyester et de l'ensimage sur les interactions fibres-ensimages : diffusion - répartition - cohésion". Lyon 1, 1992. http://www.theses.fr/1992LYO10063.
Testo completoSolarski, Samuel. "Développement de nouveaux filaments de polylactide nanocomposites". Lille 1, 2006. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2006/50376-2006-Solarski.pdf.
Testo completoLansiaux, Henri. "Élaboration et caractérisation de renforts tissés 3D interlock chaine en lin pour matériaux composites". Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I041.
Testo completoThe multi-scale characterisation of textile preforms made with natural fibres is a necessary method to understand and analyse the mechanical properties and behaviour of the composite. In this study, a multi-scale experimental characterisation is carried out on 3D warp interlock fabrics made with flax fibres at the fibre (micro), yarns (meso), fabric and composites (macro) scales. The mechanical tensile properties of the flax fibre were determined using the IFBT methodology. The twist effect was also taken into account in the calculation of fibre stiffness and revealed the limits of the rules of mixtures and some other models. Tensile tests on dry rovings were carried out considering different levels of twist, in order to determine the optimal twist level suited for 3D weaving process. The results reveal the importance of considering the properties of the fibre and the yarn at these scales to determine the most suitable material for weaving. At the fabric scale, seventeen 3D warp interlock fabrics were produced to understand the influence of product parameters on textile parameters and mechanical behaviour. The characterisation of 3D warp interlock woven structures shows the predominant role of yarns on structural and mechanical properties. On the following macroscopic scale, the six impregnated structures have enabled relationships to be established between the reinforcing structures and the associated composite materials. Coupled with these studies, a statistical approach provided a global vision of the product parameters that influence the 3D interlock warp interlock fabrics and the associated composite materials
Sibellas, Aurélien. "Cordes textiles torsadées à fibres continues : Caractérisation de la structure et modélisation du comportement mécanique en extension". Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI017.
Testo completoTwisted continuous filament yarns are commonly used as reinforcements in a wide variety of industrial applications and more specifically as reinforcements in tyre rubber. The yarns concerned are made of nylon, polyester or aramid fibres by twisting them together (from 200 to 1000 fibres of the same material) to obtain what is called a single yarn. The assembly of two or three single yarns by twisting them together makes it possible to build a multiply yarn that will be called hybrid if the initial single yarns are made of different fibres. All configurations give a wide range of possible mechanical properties involving the effects of the material's behaviour, the local orientation of the fibres and the transverse pressures inducing an imbalance in the case of the presence of different types of fibres. This thesis presents a precise structural study of fiber orientations by X-ray microtomography of single and multiply yarns and an original tool to analyze the spatial frequencies characteristic of fiber trajectories. A mechanical model of single yarn in extension from the literature is enriched from this work supported by an additional experimental study of their lateral contraction under extension. The influence of the disorder of the initial fibre bundle on the mechanical behaviour of the final single yarns is analysed numerically by the finite element method by simulating the physical process taking place during twisting. Finally, a general mechanical model is proposed to predict the mechanical behaviour in extension of the hybrid multiply yarns, consisting of three single yarns showing different torsions
Ayad, Esma. "Développement de fibres fines multicomposantes pour la filtration de l’air". Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10159/document.
Testo completoThis study is part of the project FILAIRCO which consists in the development of fine fibers for air filtration. The ultimate goal is to increase filtration efficiency by decreasing diameter of fibers in nonwoven webs. Bicomponent melt spinning allows polymers combination according to “segmented pie” and “islands-in-the-sea” morphologies. Thus, subsequent fiber splitting is promoted by hydroentanglement process. However, components splitting requires a fiber morphology with stable and poor interface. Equivalent viscosities and difference of crystallization temperatures are the relevant parameters influencing morphologies fibers. Polypropylene (PP) and polyamide 6 (PA6) were performed within the two morphologies. Polymers are evenly distributed to avoid encapsulation phenomenon of the most viscous polymer by the less viscous one. Polymers don’t need cohesion to allow fiber splitting by hydroentanglement process. Depending on polymers localization within “islands-in-the-sea” morphology, polymers cohesion is more or less strong. PPislandsPA6sea association with poor interface enables fiber splitting unlike PA6islandsPPsea fiber. Both fibers PA6islandsPPsea and PPislandsPA6sea (diameter ~ 26 µm) are performed using carding and spunbond processes and fiber splitting is allowed with hydroentanglement process. Air permeability and SEM analysis show fiber splitting is promoted for PPislandsPA6sea couple. Decrease of fiber diameter from 3.6 to 1.1 µm is allowed with increase of islands in the morphology from 37 to 300. Finally, influence of draw ratio on polymers cohesion and decrease of fiber diameter are studied to optimize bicomponent melt spinning process parameters
Bilal, Mohammad-Bassem. "Etude des corrélations structure-propriétés tinctoriales des fibres d'acide polylactique (PLA)". Phd thesis, Université de Haute Alsace - Mulhouse, 2010. http://tel.archives-ouvertes.fr/tel-00712551.
Testo completoPauli, Nicolas. "Recherche de forme et analyse statistique orthotrope de membranes textiles architecturales". Montpellier 2, 1994. http://www.theses.fr/1994MON20002.
Testo completoNeagu, Ionut. "Contribution à la modélisation et à la simulation tridimensionnelle de l’interface fibres/fil". Thesis, Lille 1, 2010. http://www.theses.fr/2010LIL10029/document.
Testo completoThe basic need of this study, would be to predict accurately yarn structure behavior based on the physical behavior and mechanical properties under different loads applied to the range. Beyond the scientific nature of the forecast, we can use the same computer to simulate virtually ground tests and laboratory experiments (prediction of new material technology) or to generate realistic animation art characters (design of textiles and clothing).Therefore, to model and to predict the different behavior in the chain of textile design by the a tool provides a gain of time and considerable manpower. Simulation of laboratory tests for textile products in the clothing industry may eventually lead to improved products, lead to higher rates of successful or reduce the amount of unsold goods, and lead ultimately to an increase in sales. In computer graphics, it is possible to implement a virtual chain of comparative testing using a specific standard based on criteria of quality obtained by simulation. The innovative aspect of our research is the generation of a structure with a variable diameter structure. The real model of the yarn is simulated by presenting a preliminary 2D structure that simulates the change in diameter and after the 3D presentation of it, the repetition of the simulated part is also an important part.The use of interpolation curves represented by Bezier polynomials in the context of this work represents a new approach, especially in the area of natural yarns sectional variation.In this context we obtained a valid model of the yarn in order to extended and validated theother one that are allready developed The main objective of this work is to complement research conducted in the framework of modeling and simulation applications textiles. By using 3D tools, companies can reduce the time required for product improvement. The immediate consequences are the reduction of costs and working hours. The increased power and speed of computing technologies, but also reducing their prices, make possible the implementation of virtual tools to improve the realistic level of quality and technical simulations
Zrida-Ammar, Hana. "Les composites avec mesostructure en faisceaux : propriétés élastiques et endommagement". Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0280/document.
Testo completoTextile composites with bundle meso-structure have been studied in this thesis for elastic properties and damage investigations. The first chapter of this thesis deals with elastic properties modeling for Non-crimp fabric (NCF) based composites for investigating the effect of meso-structure defects on mechanical properties degradation. The objective of the work is to formulate a model for the NCF composite mesostructure in an attempt to investigate the effect of the waviness on stiffness reduction. The cross-ply NCF composite stiffness reduction is dominated by the stiffness reduction of the 0°-layer. The 0°-layer effective stiffness can be determined either by modeling a single curved tow subjected to distributed load, to reproduce its interaction with the neighboring layers, together with symmetry boundary conditions, or using a master curve approach, where a knock down factor is introduced to characterize the stiffness reduction and analytical expression is suggested. This expression allows for determination of knock down factor for any given wavelength and amplitude of the waviness. The damage initiation and development is presented is the second chapter, where woven fabric composites designated for high temperature application were investigated under severe thermal conditions to study their thermal stability and their resistance to thermal damage. Finally, the mechanical performance of the composites designated to high temperature applications was studied. The effect of aging was also investigated. 3D models were realized with Finite elements in order to explain the edge effect on the evolution of the cracks observed during the tensile tests. In addition, the differences and similarities in cracking in different layers were analysed using probabilistic approaches (a simple one as well as Monte Carlo simulations with Hashin’s and also shear lag model) and fracture mechanics arguments
Vafaee, Maedeh. "Conception, développement et caractérisation des fibres spécifiques activées (composite nanoweb) pour le traitement des rejets de l'industrie textile". Thesis, Mulhouse, 2019. http://www.theses.fr/2019MULH3062.
Testo completoIn this research, at first, a new catalyst was synthesized by a new combustion method and it was also characterized and applied in a photo-catalytic reactor to degrade the organic compounds. Then, these photocatalysts were immobilized on the surface of nonwovens of polyamide nano fibers obtained by the electro-spinning process using a semi-industrial machine. Then, the mechanical behaviors of polyamide (PA) nano-fiber nonwovens were studied in the short and long term by tensile and creep test. This allowed on the one hand to evaluate finely the properties of nonwovens and on the other hand to model their behavior on average of analog models. The generalized Kelvin-Voigt model has shown its robustness. They were installed on the reactor wall in order to have a stainless steel fixed bed reactor and to avoid the disadvantages of a heterogencous system. The solution analysis results showed us a favorable degradation of organic compounds and intermediate products in a closed circulation system. Pressurizing the reactor confirmed, as shown in the mechanical tests, that the mechanical properties of the doped fibers were sufficient to withstand the mechanical stresses associated with the flow of the Jiquid
Duchamp, Boris. "Contribution à l’élaboration de préformes textiles pour le renforcement de réservoirs souples". Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10081/document.
Testo completoThe dimensioning of the aircraft tanks is based on the performance levels to satisfy with respect to certifications described in MIL-TLD-27422-E. These performances are evaluated among others on the self-sealing capacity by a ballistics test but also for crash resistance by a "drop -test." For this test the tank, filled, is dropped in free fall from a height and hits the rigid ground, the integrity (without leakage) of the tank has to be preserved. Flexible tanks are consisted of three major components: an inner layer in contact with the fluid, a layer mainly dedicated to the self-sealing function, and a number of layers of elastomeric reinforced fabric for anti-crash properties. The lightweight approach led to rethink the design of these tanks while maintaining the performance levels in relation to these specifications. To do this, it is mainly the heavier layer, composed of coated textiles, which is to be optimized. This thesis work is part of this context, in the FUI Balloo project and aim to reduce the number of layers, incorporating textile reinforcement structures (exoskeleton) around bladders. The development of these textiles by braiding structures, the geometric characterization but also mechanical in uniaxial tension of these reinforcements have been the heart of the developments made. In this work, the braiding process is positioned relative to other textile reinforcements elaboration technologies. With the braider machinery available in laboratory GEMTEX (EA No. 2461 ENSAIT), and by a control of the process parameters, various braids configurations have been developed. An experimental approach of geometrical and mechanical properties characterization of these braided structures was conducted and was associated with a modeling approach of these characteristics. Finally these braided structures, assembled on a prototype tank were also tested on this scale
Kamdem, Signe Christian. "Caractérisation et modélisation du comportement mécanique des structures tissées aux températures cryogéniques". Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1I063/document.
Testo completoThe exploitation and use of Liquefied Natural Gas (LNG) is growing worldwide, resulting in a booming market with many LNG terminal installation projects. These liquefied natural gas installations, which operate at very low temperatures (~ -160 ° C) to facilitate its transport, however require continuous maintenance without cutting the supply valves upstream or downstream. This study is a part of a global project funded by the government named CRYOBTURE which aims to design and develop a new solution of inflatable shutter to facilitate the maintenance of LNG (Liquefied Natural Gas) pipeline facilities. This solution would be obtained from a sealing balloon formed of several layers coated textile composite materials capable of obstructing the flow of LNG. Th question is therefore to find the ideal composition and combination of these woven structures which must have optimum mechanical properties and in adequacy with the operating conditions, in particular in terms of breaking strength and deformability. At first, the mechanical behavior in tension of certain synthetic textile fibers was investigated under cryogenic temperatures. The analysis of the obtained results made possible to discriminate some of them with regard to their mechanical properties and thus to make choices that were exploited for the elaboration of the woven structures. From there, we have been able to characterize the tensile mechanical behavior at cryogenic temperatures of some coated woven structures obtained from the previous fibers. The analysis of the various results allows us to consider several architectures for designing the shutter and thus to propose choices on the woven structures for each of the composite layers of the LNG shutter. These structures generally exhibit nonlinear orthotropic behavior. Modeling such behavior requires the use of specific models such as Fung's. We were able to numerically simulate the mechanical and thermal behavior (decoupled) of the shutter in an LNG environment.The results of this project have shown a number of limitations but open up prospects in terms of transfer to other application sectors requiring flexible supports subjected to cryogenic temperatures
De, Luycker Emmanuel. "Simulation et expérimentation en mise en forme de renforts composites 3D interlocks". Phd thesis, Lyon, INSA, 2009. http://oatao.univ-toulouse.fr/18622/1/DeLuycker_18622.pdf.
Testo completoMerotte, Justin. "Contribution a l'étude des matériaux composites renforcés par des fibres végétales aiguilletées". Thesis, Lorient, 2017. http://www.theses.fr/2017LORIS444.
Testo completoProposing solutions to produce more efficient and environmentally friendly automotive parts has become a major challenge for tier one suppliers. The work described in this thesis is about understanding and improving composite materials made with commingled plant fibre nonwovens. From the same initial nonwoven, it is possible to obtain very distinct material structures by controlling porosity content. One can then give to the material enhanced acoustic properties with high porosity content (50%) or in the contrary show good mechanical properties by limiting porosities. Material structure will evolve with porosity as well as its mechanical behavior. Thus, as function of porosity, interfacial adhesion of fibre mechanical properties will govern composite mechanical properties. Biocomposite automotive parts are exposed to a large range of climatic environments and their mechanical properties can vary significantly. Indeed, radial stresses are drastically influenced by the reinforcement hygroscopic state. Finally, the idea developing an innovative material structure from compression moulding wastes has helped enhancing material rigidity
Zahour, Selim. "Performances de fibres synthétiques issues du recyclage. Role des propriétés aux interfaces sur le comportements au temps et à l'usage". Thesis, Normandie, 2018. http://www.theses.fr/2018NORMR019/document.
Testo completoWe focused on physical ageing of a non-woven produced by recycled fibers from plastic bottles. This non-woven is produced by drylaid-textile process and is used for building thermal insulation. Two networks are visible and structural relaxation has been investigated through the study of evolution of one fiber skin part with different couple time, temperature. Physical ageing of polymers can be followed by structural relaxation process. We showed that structural relaxation process is very long for temperatures of use far from glass transition temperature. Same results have been shown on the global non-woven stored in non-insulated box governed by Normandy weather. The combination of the two previous results reinforce our basic idea ; the insulator properties variation will be stable for long time only if temperature of use is far from glass transition temperature
Chatain, Szostkiewicz Catherine. "Méthodes mixtes numériques et expérimentales pour la caractérisation en rigidité et la fissuration de membranes composites orthotropes". Lyon 1, 1998. http://www.theses.fr/1998LYO10288.
Testo completoNauman, Saad. "Geometrical modelling and characterization of 3D warp interlock composites and their on-line structural health monitoring using flexible textile sensors". Thesis, Lille 1, 2011. http://www.theses.fr/2011LIL10010/document.
Testo completoThis thesis is divided in two parts. In the first part a geometrical modelling approach has been developed in tandem with weaving parameters. The reinforcements were woven on a modified conventional loom to study the geometry of these structures. Their weaving has been described in detail. The weaving parameters have been correlated to the modelling approach. The meso structural modelling approach is capable of predicting essential reinforcement geometrical characteristics at meso structural level without being too complicated. Furthermore, mechanical characterization of 3D interlock reinforcements has been carried out in such a way that a track of mechanical properties during the complete production cycle has been maintained. A novel parameter called strength transfer coefficient was proposed which allows better understanding of the influence of structural parameters on the final properties of the composite. In the second part of the thesis an online structural health monitoring system which is composed of a textile based sensor and signal amplification and treatment module, has been developed. This system is capable of detecting structural deformations in the composite as the sensor is integrated during the manufacturing of the reinforcement and can follow its deformation pattern when composite is subjected to tensile loading in a real time
Glé, Philippe. "Acoustique des Matériaux du Bâtiment à base de Fibres et Particules Végétales - Outils de Caractérisation, Modélisation et Optimisation". Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00923665.
Testo completoMailler, Philippe. "Rhéologie des membranes composites souples orthotropes sous chargement multi-axial". Lyon 1, 1996. http://www.theses.fr/1996LYO10143.
Testo completoLei, Lei. "Étude des matériaux poreux thermo compressés pour la modélisation des écrans acoustiques automobiles". Thesis, Compiègne, 2018. http://www.theses.fr/2018COMP2428/document.
Testo completoThis work was carried out in the framework of the project EcOBEx, whose main objective was to reduce the passby noise by mean of acoustic shields in the engine compartment of the vehicle. The acoustic shields are manufactured by thermocompression of uniform porous materials. The material’s properties and thickness evolve according to the degree of compression experienced by the material. The objective of this work is to propose some laws to predict the evolution of the materials properties from their initial non compressed values and the compression rate. Firstly, we focus on the parameters of the Johnson-Champoux-Allard-Lafarge (JCAL) equivalent fluid model : porosity, air-flow resistivity, tortuosity, viscous characteristic lengths, thermal characteristic length, static thermal permeability. Some analytical expressions are proposed to predict the variation of these parameters as a function of compression. They are derived from a physical model of cylindrical fibres where the fibre orientation variations induced by the thermocompression can be taken into account. The results are in good agreement with the measurements made two types of materials (open cell foam and fibrous). A generalized empirical model is finally proposed for the air-flow resistivity.In a second part, we focus on the elastic parameters, which are necessary to take into account the vibration of the skeleton. The quasi-static experimental method is first applied to study the evolution of the Young’s modulus along the compression rate for fibrous and open cell foams. A power law is then proposed to predict these variations. Finally, an inverse method for estimating the elastic properties of an orthotropic poro-elastic material from a vibratory measurement of a thermocompressed three layer sandwich structure is proposed. This method allows us to characterize the elastic properties of a porous material in a situation close to its actual application
Alruhban, Ayham. "Contribution à l'analyse de la déformabilité de renforts tricotés". Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10103/document.
Testo completoDuring the manufacturing process of composite materials, such as «RTM» (Resin Transfer Moulding); resin is injected through the preformed reinforcement. The mastery of dry reinforcement layout in the mold is essential for defects control. Many studies cover wide areas related to this step for woven reinforcements, while few studies have focused on the deformability of knitted reinforcements at forming stage in spite of their significant extensibility and their potential as reinforcements of composite materials. The macroscopic behavior of the technical textiles is mainly due to their structural effect. In this research, the development and detailed design of knitted reinforcements in order to understand the specific parameters as textile structures are carried out. An experimental study of the uniaxial tensile mechanical behavior is conducted. The mechanical behavior of knitted structures in different orientations is analyzed by using contactless deformation measurements. In association with the characterization of in-plan behavior, forming tests of dry knitted reinforcements are performed on a special rig. Analysis of the results in terms of shortening, forming forces and local deformations shows the specificity of the deformability of these structures compared with woven reinforcements. To describe the formability of the knitted reinforcements, a correlation between the tensile and forming behavior is given
Apolinario, Testoni Guilherme. "Analyse en service de la durabilité à long terme des biocomposites en environnement marin". Thesis, Paris, ENMP, 2015. http://www.theses.fr/2015ENMP0046/document.
Testo completoThis work aims to address a complete analysis of the use of flax fibres to substitute glass fibres in composite materials designed for nautical applications. This substitution requires a better understanding of the composites life cycle: from materials selection and processing to its hydric ageing, especially under real conditions (exposition to water, temperature and mechanical loadings).A preliminary study is devoted to the selection of materials (flax fibre fabrics and polyester resin) and to the comparison between two methods for manufacturing composites (vacuum infusion and compression moulding) through their mechanical and the morphological properties.The ageing behaviour of flax fibre reinforced composites (FFRC) and glass fibre reinforced composites (GFRC) is then studied. A set of original methods have been implemented to monitor the evolving morphology (water uptake, swelling) and mechanical properties (statics and dynamics). First of all, hydrothermal ageing of glass and flax fibre composites is characterized until water saturation. This step is followed by the study of a drying phase in order to verify the reversibility of physical and mechanical properties. In parallel, a particular issue of this work was devoted to reducing the hydrophilicity of flax fibres into composites.The hydrothermo-mechanical coupling behaviour of biocomposites is then studied by imposing a creep solicitation to biocomposites immersed in water. The application of this methodology highlighted the significant influence of the coupled solicitations. Contrary to all expectations, superimposing a load during a hydrothermal ageing slows the loss of the elastic properties in comparison with the sum of the uncoupled ageing effects.Finally, a finite element model was stablished in order to predict the hydric diffusion within the composite material. The 2D model integrates the real morphology of composites, and particularly the organisation of the flax fibres in the matrix at different scales. This modelling represents the first step in predicting the evolving behaviour of biocomposites exposed to ageing conditions