Дисертації з теми "Matériaux Composites à Renfort Tissé"
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Couégnat, Guillaume. "Approche multiéchelle du comportement mécanique de matériaux composites à renfort tissé." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2008. http://tel.archives-ouvertes.fr/tel-00403885.
Elleuch, Riadh. "Etude du couplage entre le vieillissement hygrothermique et la tenue en fatigue de composites à renfort tissé utilisés en construction navale." Ecully, Ecole centrale de Lyon, 1996. http://www.theses.fr/1996ECDL0051.
Huang, Jin. "Simulation du drapage des renforts de composites multicouches liés par piquage." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI098.
Nowadays, composite materials make it possible to reduce the mass of parts and are widely used in the aerospace, aeronautics and automotive industries. In addition, the multilayered reinforcement of composites allows the design of thick structures such as the fan blades of aircraft engines. However, many defects can occur during the forming process of multilayered reinforcements, such as the wrinkling problem. Research on the formation of wrinkles, as well as on the tufting technology to improve the mechanical property of multilayered reinforcements in the direction of thickness are presented in this work. The first part of this report is a study of the formation of the wrinkles of multilayered reinforcements subjected to out-of-plane bending. Firstly, the influence of the different orientations of the layers on the formation of wrinkles is explored. The relationship between the load applied to the fabric and the creation of wrinkles is thus shown. The second chapter compares two types of weaving pattern on the drapability of the composite. The third part consists of developing two numerical models adapted to simulate the forming of tuft-bonded composite reinforcements. These approaches involve the use of a stress resultant shell element to represent each layer of reinforcement and bar elements to represent the tufting yarn. These models require a specific contact algorithm to manage the interaction between the reinforcement and the tufting yarn. Finally, the last part consists of validating the models by comparing simulations and experiments
Van, Den Broek D'Obrenan Ghislain. "Adaptation du procédé RTM (Moulage par Transfert de Résine) à la mise en œuvre de matériaux composites à matrice thermoplastique." Phd thesis, INSA de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00715806.
Vilfayeau, Jérôme. "Modélisation numérique du procédé de tissage des renforts fibreux pour matériaux composites." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0026/document.
The aeronautical industry faces new challenges regarding the reduction of fossil fuel consumption. One way to address this issue is to use lighter composite materials. The ability to predict the geometry and the mechanical properties of the unit cell is necessary in order to develop 3D reinforcements in composite materials for these aeronautical applications. There is a difficulty to get realistic geometries for these unit cells due to the complexity of their architecture. Currently, existing tools which model 3D fabrics at a meso scale don't take into account manufacturing process influence on the shape modification of the textile structure. There is already some numerical tools that can model the braiding or knitting process, but none have been developed for weaving so far. Consequently, this study deals with the numerical simulation of the weaving process to obtain a deformed dry fabric structure. During the weaving process of E-glass fabrics, achieved in our laboratory, it has been observed that large deformations led to the modification of transverse section of meshes, or local density changes, that can modify the fabrics mechanical resistance. For this reason, a numerical tool of the weaving process, based on finite element modelling, has been developped to predict these major deformations and their influences on the final textile structure. The correlation between numerical results and fabrics produced with glass fibres has been achieved for plain weave and 2-2 twill
Van, den Broek d'Obrenan Ghislain. "Adaptation du procédé RTM (Moulage par Transfert de Résine) à la mise en œuvre de matériaux composites à matrice thermoplastique." Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0112/document.
The "Resin Transfer Molding" (RTM) process is very largely used for the industrial production of composites materials with thermoset matrix. Indeed, it’s used by many fields such as the automotive and aeronautics. In this work we adapted this process to the manufacture of composite materials with thermoplastic matrix in order to answer the ecological and economic criteria imposed on industries. For that several steps were necessary. The first was the selection of a robust chemistry, adapted to the requirements of the process (low initial viscosity of the reactive system, polymerization time, etc). The selected chemistry, was the ring opening polymerization of ε - caprolactam to obtain polyamide-6 (PA-6). Rhéo-kinetics studies, as well as the physicochemical characterizations of a Pa-6 obtained at the laboratory were carried out. Following this step, tests in conditions of process were carried out with the use of dedicated pilot equipment. These tests were the source of modifications and optimizations of certain parameters of the process. The third step, consisted with the production of composite parts with a reinforcement of the type: unidirectional glass fabric. This production was followed mechanical and physico-chemical tests in order to evaluate the properties of these parts. Various sizing of the glass fabric were studied with, for objective, to determine which to offer the best properties. During this study we observed the low impact of the sizing on the chemistry of PA-6. To finish, we set up a reactive sizing which will allow a better interaction fibre/matrix
Bai, Renzi. "Modélisation de la mise en forme des renforts fibreux : Nouvelle Approche de coque spécifique et étude expérimentale." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI108.
The deformation of textile composite reinforcements is strongly conditioned by their fibrous composition. Classic plate and shell theories are based on kinematic assumptions that are not verified for textile reinforcements. Experiments show that the slippage between fiber (layer) in the thickness makes the specificity of fibrous materials. The RTM process (one of the forming process) is widely used to obtain composite parts with complex geometry is with great importance. In order to optimize the manufacturing of product, numerical models are necessary. Therefore, a 3D shell approach specific to fiber reinforcements is proposed which is based on two specificities: the quasi-inextensibility of the fibers and the possible sliding between the fibers. This approach is developed in the frame of continuum-based shell, the new assumption who based on the conservation of the thickness is applied to the kinematic equation. The theory of virtual power reflects the specific deformation of the fibrous reinforcements. It considers the tensile and bending stiffness of the fibers and the in-plan shear stiffness. The friction between fibers is taken into account in a simple way in connection with bending. The present approach is based on the real physics of the deformation of textile reinforcements. It simulates the 3D deformations of textile reinforcements and provides displacements and deformations for all the points along the thickness of the fabric and simulates the correct rotations of the material director. Finally, experiments and simulations performed on multilayer reinforcements are presented in this work, and a new method of experimentation is proposed
Mathieu, Sylvain. "Modélisation du comportement mécanique lors du procédé de mise en forme et pyrolyse des interlocks CMC." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0115/document.
Manufacture processes modeling of woven fabrics composites is a major stake for state-of-the-art industrial parts, where their usage is intensifying. Control of all the manufacturing stages of ceramic matrix composites, particularly the forming and pyrolysis steps, is essential. Understanding and simulation of the mechanical behavior at each stage is required to optimize the final product performances. Two macroscopic modeling approaches of thick woven fabric reinforcements are detailed: a continuous classical one and a semi-discrete one. An initially orthotropic hyperelastic constitutive law is thus established. This law is based on a phenomenological observation of the main fabric deformation modes, from where physical invariants of the deformation are suggested. The required material parameters identification is explained. A modified version of this law, without any tensile energetic contribution, is implemented in a semi-discrete element where the tensile work is taken into account by bars that discretize the real weaving. Thick woven reinforcements are highly anisotropic materials due to the large ratio between the tensile rigidity and the others. Their numerical modeling highlights spurious phenomena and limitations related to this specificity. The tension locking is firstly tackled. A remedy based on an enhanced assumed strain finite element formulation is suggested for classical continuum and semi-discrete elements. Problems linked to bending-dominated numerical simulations are brought to attention : transverse hourglassing and lack of local bending stiffness. For the transverse hourglassing situation, two stiffening technics are proposed : averaging the dilatation through the whole element or adding a supplementary tangent material rigidity in a specific direction. The local bending stiffness problem is solved by calculating the curvature inside the element by using rotation free plates. The induced bending moment leads to supplementary internal loads. Finally, the elastic springback following the pyrolysis of the polymer matrix with ceramic precursors is modeled. The constitutive behavior is experimentally identified with a transverse isotropic hyperelastic law. Added to the initial reinforcements’ hyperelastic law, with the preformed fabric as reference configuration, the pyrolysis induced deformations can be visualized. This final model is compared with experimental results
El, fallaki idrissi Mohammed. "Réduction de Modèles et Réseaux Neuronaux Artificiels pour une Simulation Multi-échelle Rapide et Précise des Matériaux Composites à Microstructure Périodique." Electronic Thesis or Diss., Paris, HESAM, 2024. http://www.theses.fr/2024HESAE012.
Although woven reinforced composites are experiencing rapid growth across various engineering and industrial domains, their widespread adoption is often hindered by challenges in accurately predicting their mechanical behavior. This obstacle primarily stems from the heterogeneous nature of these materials. Consequently, employing multi-scale approaches becomes imperative to predict their overall response under complex loading conditions, incorporating detailed descriptions of microstructure and the constitutive laws governing their components. However, effectively incorporating these methodologies into real-scale applications, particularly within FE² analyses, remains challenging due to the significant computational requirements they entail. This challenge intensifies when numerous direct calculations are necessary for testing various configurations, a critical aspect in optimization, inverse analysis, or real-time simulations. The need for such calculations adds to the computational demands, posing a significant obstacle to integrated into practical applications. To address these issues, while considering the scale effects, this thesis aims to develop efficient numerical tools to achieve accurate and fast predictions of woven composite response. First, we develop virtual twins (multiparametric solution) for real-time prediction of composite response, using non-intrusive Proper Generalized Decomposition (PGD) based methods. This aims at providing an accurate approximation of high-dimensional problems, that involved several microstructural parameters, with limited dataset. These multiparametric solutions are constructed for both linear and nonlinear behavior including history- and rate-dependent behaviors. Second, we develop an approach based on ANN to perform a macroscopic surrogate model of composites. This model, referred to as Multiscale Thermodynamics Informed Neural Networks (MuTINN), is founded on thermodynamic principles and introduces specific quantities of interest that serve as internal state variables at the macroscopic level. This captures efficiently the state and evolution laws governing the history-dependent behavior of these composites while retaining the thermodynamic admissibility and the physical interpretability of their overall responses. This approach has successfully associated with FE code, streamlining the application of multiscale FE-MuTINN approach for composite structure computations. The prediction capabilities of the proposed approach are demonstrated across the material scales, exemplified through diverse instances of woven composite structures. These applications account for anisotropic yarn damage and an elastoplastic polymer matrix behavior. This promises a potential solution to alleviate the computational challenges associated with multiscale simulations of large composite structures and paving the way for the development of a hybrid twin solution
Steer, Quentin. "Modélisation de la mise en forme des renforts fibreux cousus (NCF) : Etude expérimentale et numérique de l’influence de la couture." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI115.
Continuous fibre composites (carbon, glass) are regularly used in the transport industries (automotive, aeronautics) for their excellent mechanical performance in relation to their mass. While woven reinforcements are widely used and studied, there is a growing interest in stitched reinforcements called "non crimp fabric" (NCF). These reinforcements consist of juxtaposed plies of unidirectional fibres , non-woven, but sewn together with a stitching thread. They allow a greater variety of fibre orientation and optimize the properties of the composite by reducing fiber interweaving. The manufacture of composite parts by automated processes such as RTM (Resin Transfer Molding) involves the forming of fibrous reinforcements to obtain complex 3D geometries. The draping of NCFs is strongly impacted by the presence of the stiching thread. The development of simulation tools should enable the manufacture of these products to be optimize. This work focuses on the mechanical role of stitching during forming. The study focuses on experimental tests and finite element simulations in explicit dynamics of various NCF reinforcements. Different modelling approaches at macroscopic scale are proposed for NCFs, based on previous work on woven reinforcements : integration of stitched thread and the stitch pattern into the laws of behaviour; development of models mixing continuous finite elements for fibre modelisation, and semi-discrete models for the stitch. The performance of these different approaches is compared with experimental results. Finally, a new contribution is add to consider the bending rigidity in the plane of the fibrous reinforcements by generalizing the use of finite elements shell called "rotation-free" for the calculation of all the curvatures (out of plane and in the plane)
Aridhi, Abderrahmen. "Analyse structurelle des composites tissés prenant en compte le procédé de mise en forme." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI012/document.
During the forming process, the woven fabric/prepreg can undergo large fiber rotations due to plane shear deformation. These rotations are mostly important in zones with complexe gometries such as double curvature. Therefore, the fiber reorientations in the new sheared fabric affects significantly the strength and performance of final product. The aim of this thesis work is to develop a constitutive model that taking into account the angle's between the weft and warp yarns. An hypoelastic model has been developed in order to simulate the forming of dry fabric. The forming simulation allows to determine the final reorientations between yarns through the shear angles. The later are transferred into an orthotropic elastic model, developed to perform a structural analysis of a cured composite after its forming. The orthotropic model has been validated by a tensile test on cured specimens after a bias extension test. Finally, to demonstrate the performance of this orthotropic model (taking into account the reorientation of yarns), FE analysis on cured hemisphere and double dome have been performed. The results obtained by the orthotropic model have been compared with those obtained from a model without taking into account the reorientation of yarns
Charmetant, Adrien. "Approches hyperélastiques pour la modélisation du comportement mécanique de préformes tissées de composites." Phd thesis, INSA de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00706212.
Florimond, Charlotte. "Contributions à la modélisation mécanique du comportement de mèches de renforts tissés à l'aide d'un schéma éléments finis implicite." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0136/document.
Simulating the manufacturing process of woven preforms is a major stack for understanding the development of composite materials, used in high performance industries. The effect of the weaving loom on the preforms is very important to caracterize their mechanicals properties. Experimental tests are realised to identify the physical phenomenon. Different deformation modes are studied : elongation, compaction, shear and distortion. The bending and friction behavior are also important to understand the effect of weaving process. Two constitutive laws are considered : a hypoelastic law and a hyperelastic law. An analyse of their properties is presented, and their implementation in a commercial software, ABAQUS/Standard, is detailed. In this purpose, two subroutines can be used. The modelisation of the mechanical behavior of the tows is finally realised with a transversely isotropic hyperelastic St-Venant model, with the subroutine ABAQUS/Standard UANISOHYPER_INV. To conclude, an identification method is presented and the simulated results are compared to experimental tests. The obtained consitutive behavior is finally used to simulate the weaving process
Grail, Gaël. "Approche multimodèle pour la conception de structures composites à renfort tissé." Phd thesis, Université d'Orléans, 2013. http://tel.archives-ouvertes.fr/tel-00919198.
Naouar, Naïm. "Analyse mésoscopique par éléments finis de la déformation de renforts fibreux 2D et 3D à partir de microtomographies X." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0088/document.
The simulation at meso-scale of textile composite reinforcement deformation provides important information. In particular, it gives the direction and density of the fibres that condition the permeability of the textile reinforcement and the mechanical properties of the final composite. These meso FE analyses are highly dependent on the quality of the initial geometry of the model. Some software have been developed to describe composite reinforcement geometries. The obtained geometries imply simplification that can disrupt the reinforcement deformation computation. The present work presents a direct method using computed microtomography to determine finite element models based on the real geometry of the textile reinforcement. The FE model is obtained for any specificity or variability of the textile reinforcement, more or less complex. The yarns interpenetration problems are avoided. These models are used with two constitutive laws : a hypoelastic law and a hyperelastic one. An analysis of their properties is presented and their implementation in the software ABAQUS is detailed. Finally, an identification method is presented and the results of forming simulations are compared to experimental tests, which shows a good fit between the both
Azehaf, Ismael. "Modélisation du comportement mécanique et de la perméabilité des renforts tissés." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI079.
The manufacture of composite parts by Resin Transfert Molding (RTM) requires to control two main phases: the shaping of the dry reinforcement and the injection of the matrix. Numerical simulation is a powerful tool when it comes to find the right set of parameters needed to obtain a part without non conformity. These research works where performed in this specific field with two main contributions: Mesomechanic: textile fabrics are periodic porous media. Modelling these materials at the mesoscale permit to reduce the geometrical model to a Representative Volume Element (RVE). At this scale the boundary value problem to solve is highly nonlinear: non linear behavior of the yarns, large deformations and contact. Solving this problem with a Finite Element Method include dealing with contact surface generation between the RVE and its neighbors. Part of the RVE yarns deformation is coming from these multiple contacts at the borders. There is no methods yet that solve this issue. The first objective of this thesis is to produce one. Permeability: the quality of the composite part at the end of the manufacturing process depends also of the matrix/reinforcement assembly. One of the parameters that influence the efficiency of this linkage is the permeability of the reinforcement. Measuring permeability throughout experiments is not easy. Numerical simulation offers another way to estimate the permeability of a textile fabric. Numerous works have been performed in this subject especially on 2D textiles. The second objective of this thesis is to propose a method for the numerical estimation of the permeability tensor of 2D and 3D textiles
Chouchaoui, Cherif-Saâdane. "Modélisation du comportement des matériaux composites à renforts tissés et à matrice organique." Compiègne, 1995. http://www.theses.fr/1995COMP854S.
Lansiaux, Henri. "Élaboration et caractérisation de renforts tissés 3D interlock chaine en lin pour matériaux composites." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I041.
The 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
Lefebvre, Marie. "Résistance à l’impact balistique de matériaux composites à renforts Interlocks tissés : application au blindage de véhicules." Valenciennes, 2011. https://ged.uphf.fr/nuxeo/site/esupversions/25e254d5-2d8c-4d76-9959-cb97a45dcce8.
This study is a part of an innovative exploratory research with the financial support of the DGA. The aim is to study the impact behaviour of Interlock composite materials. The final objective is to integrate a composite material based on Interlock weaving structure into vehicle armor system that will be placed as backing of a metal panel used to fragment the FSP projectile during the impact. The composite materials should absorb the impact energy during impact and stop the metal fragments after penetration of the metal panel by the projectile. The fabrication of these materials leads to create woven Interlock structures on a weaving loom and the implementation of the fabrics by infusion process. The materials are then impacted. A criterion of comparison was used, taking into account the speed limit perforation of the material and the area density of each impacted structures in order to compare the ballistic performance at the same weight. For this study we have made the choice to produce three Interlocks weaving structures with the same weaving parameters. We also choose to use two types of fibres, Kevlar® and Vectran® for each structure. The change of the weaving process and the infusion of materials allowed us to bring out two Interlocks structures composed of Vectran® fibres with the impact criterion equivalent to the structures currently used in the field of vehicle armor
Ratiarisoa, Lisa Barbara. "Etude de matériaux naturels 2D : Potentialités d'utilisation comme renfort de matériaux composites." Thesis, Antilles, 2019. http://www.theses.fr/2019ANTI0393.
Facing the worldwide environmental, social and economic crisis awareness, the possibility ofreinforcing composites by a lignocellulosic textile reinforcement, the coconut leaf sheaths fromCocos nucifera L. was assessed in this work. The exploratory phase of sheaths characterizationhas shown that this resource forms a two-way textile made up of cellulose mostly. In contrast toclassic vegetable reinforcements, it is less hygroscopic, lighter with best tensile mechanicalproperties in preferential fibers directions. About the experimental campaign on the treatmentseffect, xylanase and laccase treated sheaths show a slight surface chemical change. Pyrolysedfibers are more hydrophobic but less resistant translating a damaging of them. Lime treatedsheaths show a higher thermal stability. Thus, raw sheaths were retained to reinforceparticleboards, the temperature of panels manufacture being lower than the start degradationtemperature of the raw sheaths. The two-faces panel covered with raw sheaths top part forms themost promising candidate to develop thermal eco-insulator. Some of its mechanical and physicalproperties fulfill american and european standards. Its thermal properties are similar to the onesnoticed in the bibliography for low density lignocellulosic particleboards
Labanieh, Ahmad Rashed. "Développement de renfort 3D multiaxial tissé pour les structures de composite : technologie, modélisation et optimisation." Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10163/document.
3D weaving technology is developed in response to the poor delamination resistance of laminated composite structures by insertion through the thickness fiber reinforcements. However, this technology is limited relatively to a possibility to insert in-plane yarns oriented other than 0° and 90°. This results in reduction of the in-plane off axis tensile properties and the in-plane shear resistance. Therefore, 3D multiaxis weaving technology has been developed in order to enable this insertion. In the thesis, a novel technique able to produce 3D multiaxis woven preforms is presented with the possibility to control the sequencing of yarn layers. The constitutive yarns and unit cell parameters of the produced samples have been measured with investigation of yarns geometry (cross section shape and path) within the structure, by analyzing the captured micrographs for the samples cross section. Predictive geometrical model has been developed. This model is indispensable design tool providing approximate estimation of the geometrical properties of the dry preforms and composites. Moreover, a geometric modeling approach is improved helping to construct an RVE of this structure as accurate as possible based on the elaborated geometrical characterization. Based on the developed RVE, a mechanical modeling has been also improved and completed using the finite element method serving firstly, to evaluate the bias yarns effect on the elastic stiffness and in-plane off-axis properties in comparison with equivalent 3D orthogonal woven composite. Secondly, it helps to investigate the influence of the in-plane layers sequence on the induced interlaminare stresses at the composite free edges
Cousigné, Olivier. "Contribution au développement de la simulation numérique des matériaux composites à renforts tissés pour l'application au crash." Thesis, Valenciennes, 2013. http://www.theses.fr/2013VALE0029/document.
This study presents the development of an experimental and numerical material characterization method relying on the investigation of the material behavior of woven composites, from the microscopic scale up to the macroscopic level by increasing progressively the complexity of the geometries and load cases. Taking into account the different limitations imposed by the industrial and engineering fields, a new numerical mesh-insensitive material model has been developed as a UMAT for the explicit finite elements solver LS-DYNA. This model accounts for nonlinearity, plasticity, failure and post-failure damage in order to predict the macroscopic behavior and the damage tolerance of woven laminated composites. It includes also a smeared formulation to avoid undesirable localization phenomena. The first step of the validation process relies on the simulation of quasi-static coupon tests, which allows to set the fundamental numerical parameters corresponding to the effective material properties and to the macroscopic behavior observed experimentally. Then, the post-failure material degradation models have been investigated using the simulations of impact tests on elementary plates and on representative parts. A satisfying agreement has been obtained for the different load cases
Wang, Jie. "Simulation macro-méso de la mise en forme de renforts tissés interlocks." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI075.
The forming stage in the RTM process is crucial because it strongly influences the mechanical behavior of composites in service. In order to better predict the appearance of possible defects of composite materials, numerical simulations are increasingly developed taking into account the duration and the cost of experiences. Deformations and orientations of yarns at the mesoscopic scale are essential to simulate the resin flow in the stage of injection. Given the number of elements and their complex interactions, it is difficult to conduct the shaping simulations for the entire reinforcement at this mesoscopic scale. This present thesis consists in developing a multiscale method that allows linking the macroscopic simulations of reinforcements and the mesoscopic modellings of RVE (representative volume element) during the forming process. Firstly, the numerical simulations for three different woven reinforcements at the macroscopic scale are carried out using an anisotropic hyperelastic constitutive law, by the finite element method with a dynamic explicit scheme. Then, the geometrical modelling of RVE at the mesoscopic scale are reconstituted based on the tomographic images. The mesoscopic displacement-deformation fields of woven reinforcements are determined from the macroscopic results and the position of the yarns. In order to take into consideration sliding effects of yarns, two approaches of mesoscopic simulations of RVE are developed. Finally, the mesoscopic numerical results are compared with the experimental results
Scida, Daniel. "Étude et modélisation du comportement mécanique de matériaux composites à renforts tisses hybrides et non hybrides." Compiègne, 1998. http://www.theses.fr/1998COMP1168.
Marcin, Lionel. "MODÉLISATION DU COMPORTEMENT, DE L'ENDOMMAGEMENT ET DE LA RUPTURE DE MATÉRIAUX COMPOSITES À RENFORTS TISSÉS POUR LE DIMENSIONNEMENT ROBUSTE DE STRUCTURES." Phd thesis, Bordeaux 1, 2010. http://tel.archives-ouvertes.fr/tel-00481601.
Beguinel, Johanna. "Interfacial adhesion in continuous fiber reinforced thermoplastic composites : from micro-scale to macro-scale." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI051.
The present study was initiated by the development of a new processing route, i.e. latex-dip impregnation, for thermoplastic (TP) acrylic semi-finished materials. The composites resulting from thermocompression of TPREG I plies were studied by focusing of interfacial adhesion. Indeed the fiber/matrix interface governs the stress transfer from matrix to fibers. Thus, a multi-scale analysis of acrylic matrix/fiber interfaces was conducted by considering microcomposites, as models for fiber-based composites, and unidirectional (UD)macro-composites. The study displayed various types of sized glass and carbon fibers. On one hand, the correlation between thermodynamic adhesion and practical adhesion, resulting from micromechanical testing, is discussed by highlighting the role of the physico-chemistry of the created interphase. Wetting and thermodynamical adhesion are driven by the polarity of the film former of the sizing. On the other hand, in-plane shear modulus values from off-axis tensile test results on UD composites are consistent with the quantitative analyses of the interfacial shear strength obtained from microcomposites. More specifically, both tests have enabled a differentiation of interface properties based on the fiber sizing nature for glass and carbon fiber-reinforced (micro-)composites. The study of overall mechanical and interface properties of glass and carbon fiber/acrylic composites revealed the need for tailoring interfacial adhesion. Modifications of the matrix led to successful increases of interfacial adhesion in glass fiber/acrylic composites. An additional hygrothermal ageing study evidenced a significant loss of interfacial shear strength at micro-scale which was not observed for UD composites. The results of this study are a first step towards a database of relevant interface properties of structural TP composites. Finally, the analyses of interfaces/phases at different scales demonstrate the importance of a multi-scale approach to tailor the final properties of composite parts
El, Hage Christiane. "Modélisation du comportement élastique endommageable de matériaux composites à renfort tridimensionnel." Compiègne, 2006. http://www.theses.fr/2006COMP1642.
This thesis is dedicated to the modelling of the elastic damage behaviour composite material 3D reinforced. The study is articulated around three essential points: the comprehension of the damage process, analytical modelling and the optimization of architectures of the reinforcements. The studies of carbon architectures are resulting from an orthogonal weaving 3D and 5 Interlock. They are subjected respectively to compression and uniaxial tension tests. The correlation between signals of acoustic emission and the microscopic observations makes it possible to emphasize the effect of architecture on the phenomena of damages. The elastic damage behaviour until the rupture is described with a duality between an analytical model of homogenization and the criterion 3D of Tsai-Wu, coupled to damage criteria. This model takes into account the geometrical characteristic of architectures of the reinforcements. The optimization part is dedicated to minimization of the REV
Aboura, Zoheir. "Etude du processus de délaminage mode I, mode II et mode mixte (I+II) de matériaux composites à renforts tissés à différentes vitesses de sollicitation." Compiègne, 1993. http://www.theses.fr/1993COMP626S.
Badel, Pierre. "Analyse mésoscopique du comportement mécanique des renforts tissés de composites utilisant la tomographie aux rayons X." Lyon, INSA, 2008. http://theses.insa-lyon.fr/publication/2008ISAL0085/these.pdf.
The preforming stage of the RTM composite manufacturing process leads to fibrous reinforcement deformations which may be very large especially for double curvature shapes. The knowledge of the mechanical behavior of the reinforcements and their mesoscopic deformed geometry is necessary for various applications. A simulation method for woven composite fabric deformation at mesoscopic scale is presented. A specific continuum hypo-elastic constitutive model is proposed for the yarn behavior. The associated objective derivative is based on the fiber rotation. Spherical and deviatoric parts of the transverse behavior are uncoupled. X-ray tomography is used to obtain experimental undeformed and deformed 3D geometries of the textile reinforcements. The simulations performed on representative elementary volume are validated based on mechanical experimental tests and tomography images for the geometry
Nguyen, Anh vu. "Matériaux composites à renfort végétal pour l'amélioration des performances de systèmes robotiques." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22606/document.
Improvement of the robot’s performances is a major challenge in the industrial field. In general, improvement objectives are increasing workspace, transportable capacity, speed and precision of the robot. To achieve these objectives, it must increase rigidity, reduce weight and increase damping capacity of the robot. Currently, the robots are generally made of metals: aluminum or steel, which limits their performances due to low damping capacity of these materials.Composite materials present an advantage to combine different materials, which leads to a variety of composite material properties. Among the types of reinforcements, carbon fibers show high modulus that enables robotic parts with high static rigidities to be designed. However, carbon fibers have generally a low damping capacity. Natural fibers have low density, good specific properties and high damping capacity.This thesis focuses on the improvement of the performances of the 3CRS parallel robot by using the composite material to redesign robot parts initially made of aluminum. The thesis begins with static and dynamic characterizations of the original robot. Then, the shape of segments of the robotic arms is optimized with respect to applying force on the robot. A hybrid laminated composite reinforced with carbon fibers and flax fibers is proposed for the use. This combination enables to combine the advantages of two fiber types in a composite for using in high loaded components. The structure of the new hybrid laminated composite is optimized and a composite segment is then fabricated in order to validate the design. Finally, the analysis of the new robot with composite arms is executed. The result shows that the new robot has a slightly higher rigidity, lighter mass and considerably greater damping capacity in comparison with the original robot. Therefore, the application of the hybrid composite could improve the static and dynamic performances and increases considerably the accuracy in operation of the robot 3CRS
Risson, Tania. "Comportement en fluage de composites à renfort carbone et matrices époxyde et peek." Ecully, Ecole centrale de Lyon, 1998. http://bibli.ec-lyon.fr/exl-doc/TH_T1793_trisson.pdf.
Legrand, Nicolas. "Fatigue de composites à matrice métallique base titane à renfort unidirectionnel de fibres SiC." ENSMP, 1997. http://www.theses.fr/1997ENMP0844.
The primary objective of this work is to understand the physical origin of fatigue fracture at high temperature of metal matrix composites SCS6/Ti6-4, SM1140+/Ti6242 and SCS6/Ti6242. The fatigue behaviour of the material is studied in longitudinal (loading parallel to the fiber axis) and transverse (loading perpendicular to the fiber axis) orientations. In longitudinal fatigue, performed at 450 and 550°C on SCS6/Ti6-4 and SM1140+/Ti6242, three major damage mechanisms were identified : the global load transfer from matrix to fibers due to matrix cyclic softening (mechanism n°1), the local interfacial degradation close to broken (mechanim n°2) and the infuence of environment on mechanical fiber properties (mechanism n°3). Damage kinetics of these different mechanisms were identified experimentally using microscopic observations and acoustic emisson technic. A micromechanical modelling, taking into account of the statistical behaviour of fibers has confirmed and quantified influence of these mechanisms on fatigue fracture of the composite : with this model, it was demonstrated that for sufficiently high fatigue loadings (stress up to 1000 MPa), the local interfacial degradation near fiber failures may control fatigue life of the composite. At last, based on experimental acoustic emissions results, this modeling enables to predict both damage kinetics and rupture in fatigue. It is thus an interesting numerical tool to improve and optimize composite fatigue properties. As far as the transverse fatigue is concerned, it was determined in isothermal (at 600°C) and in non isothermal (between 200 and 600°C) conditions. In that orientation, damage mechanisms are due to interfacial debondings and slidings and oxidation of the carbon interface. A simple one dimensionnal "3 bars" model has been formulated (taking into account matrix viscoplasticity). It has demonstrated that cyclic viscoplasticity plays a key role in fatigue fracture along this orientation
Najjar, Walid. "Contribution à la simulation de l'emboutissage de préformes textiles pour applications composites." Phd thesis, Paris, ENSAM, 2012. http://pastel.archives-ouvertes.fr/pastel-00841194.
Cadorin, Nicolas. "Optimisation et influence sur la santé matière des conditions d'usinage d'un composite CMO tissé 3D." Toulouse 3, 2015. http://www.theses.fr/2015TOU30380.
Roussière, Fabrice. "Contribution à l'étude d'un non-tissé de fibres végétales pour le renforcement de matériaux composites." Lorient, 2010. http://www.theses.fr/2010LORIS171.
Rozycki, Patrick. "Contribution au développement de lois de comportement pour matériaux composites soumis à l'impact." Valenciennes, 2000. https://ged.uphf.fr/nuxeo/site/esupversions/7111b587-a841-4752-8ca0-c24897f59bb2.
Fiore, Lucien. "Contribution à l'étude du comportement en fatigue de matériaux composites à renfort verre unidirectionnel." Ecully, Ecole centrale de Lyon, 1988. http://www.theses.fr/1988ECDL0020.
Perreux, Dominique. "Prévisions de la durée de vie de matériaux composites verre-epoxy unidirectionnel, stratifié et tissé en contraintes complexes." Besançon, 1989. http://www.theses.fr/1989BESA2005.
Bréard, Joël. "Matériaux composites à matrice polymère : modélisation numérique de la phase de remplissage du procédé R.T.M. et détermination expérimentale de la perméabilité d'un renfort fibreux." Le Havre, 1997. http://www.theses.fr/1997LEHA0006.
Michaux, Aurore. "Amélioration de la durée de vie de composites à matrice céramique à renfort carboné." Bordeaux 1, 2003. http://www.theses.fr/2003BOR12676.
The goal of this work was to study the influence of parameters characterizing self-healing and layered matrices, which are used to improve lifetime of carbon fiber-reinforced composites. These parameters are the composition, microstructure, as well as the thermomechanical and thermochemical characteristics of each layer constitutive of the layered matrix. The first part of this work deals with (i) the characterization of the reactivity towards oxygen and (ii) the determination of the thermoelastic properties of all the constituants of the composite, including carbon fibers. In the second part, an optimization of the architecture of the layered matrix is proposed from the modelling of the internal stresses distribution and from the elaboration and characterization of model 1D composites. Finally, the last part deals with thermomechanical characterizations of 3D composites constituted by an interlocked carbon fiber preform and a self-healing and layered matrix. An optimization of the matrix architecture is more particularly studied, thanks to lifetime tests performed at high temperature in an oxidizing environment
Cadinot, Séverine. "Aspects rhéologiques de la compressibilité d'un renfort fibreux pour matériaux composites : études en compression et relaxation." Le Havre, 2002. http://www.theses.fr/2002LEHA0017.
The scope of the present work is to study the compressibility of fibrous reinforcements as it products during the manufacture of composite materials by LCM processes. Firstly compression and relaxation tests were carried out to observe the influence of type of reinforcement and control parameters of the processes (deformation rate, initial thickness of the fiber bed, maximal stress applied). We have opted for a rheological approach supported by the viscoelastic response of the fibrous material in connection with its double scale porosity structure. New constitutive equations were developped to model the mechanical response of fiber beds during compression and relaxation. By the analysis of the behavior of the rheological models examined we try to correlate the behavior of the reinforcements under compression with rearrangements and frictional effects
Dafir, Driss. "Etude de l'influence du renfort sur la cinétique de précipitation dans un composite 6061/SiCp élabore par métallurgie des poudres." Lyon, INSA, 1993. http://www.theses.fr/1993ISAL0049.
The aim of this work was the investigation of the precipitation phenomena in a 6061 alloy elaborated by powder metallurgy either unreinforced or reinforced with a 10% or 20% volume fraction of SiC particles. The precipitation kinetics were mainly followed by TEP measurements and the TTP diagram of these materials was determined in the following range of temperature : from room temperature to 400 °C. The major effect of the reinforcement is to lower the stability domain of semi-coherent and coherent phases and to accelerate the precipitation kinetics. The influence of the microstructural modifications due to the introduction of the reinforcement on the precipitation kinetics were analysed. In addition ta the well-known effect of the dislocations, this work clearly evidences the particular role of the interfaces
Gagné, Vincent. "Utilisation de profilés en matériaux composites dans les lignes aériennes de transport d'énergie électrique." Mémoire, Université de Sherbrooke, 2011. http://savoirs.usherbrooke.ca/handle/11143/1623.
Bassoumi, Amal. "Analyse et modélisation du choix des renforts pour optimiser la mise en forme de matériaux composites à base de fibres végétales." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2053.
This thesis is halfway between the study of the deformability of woven structures and the use of flax fibre as reinforcement of composite materials. The first aim of the study is the experimental characterization of the bending behaviour of tows with different structures made of flax fibres and fabrics with different weaves. Parameters such as relative humidity and the composition (100% flax and commingled tows) were also considered. The second aim of the study is to link the bending behaviour of the fabric to the bending behaviour of its constituent tows. This part starts with the geometric modelling of woven fabrics in order to follow the variation of its section in the bending direction. Mesoscopic modelling allows the analytical calculation of the geometric properties of the fabric in particular its moment of inertia. The results obtained were used in the simulation of the fabrics bending to see how far the behaviour depends on the tows bending behaviour and the moment of inertia. The bending behaviour of the fabric seems to be approached satisfactorily from these two factors. This is verified within the range of lengths considered except for high humidity (in this case, other phenomena must be considered). The study pointed out that the difference between two reinforcements tested experimentally can be predicted numerically. Thus, the fabrics designer will be able to anticipate the experimental bending stiffness of the fabric in order to adapt the weaving to the shape forming. A parametric study of the bending was also achieved in order to deduce the most influential parameters of the fabric for an appropriate weaving
Bouzouita, Sofien. "Optimisation des interfaces fibre-matrice de composites à renfort naturel." Phd thesis, Ecole Centrale de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00769959.
Baziard, Yves. "Synthèse sous micro-ondes et caractérisation physico-chimique de matériaux composites à matrice polymère thermodurcissable et à renfort métallique finement divisé." Toulouse, INPT, 1986. http://www.theses.fr/1986INPT002G.
Hamdi, Khalil. "Fonctionnalisation de matériaux composites à renfort carbone et matrice thermoplastique par adjonction de nanocharges : élaboration et étude du comportement." Thesis, Compiègne, 2017. http://www.theses.fr/2017COMP2388/document.
To extend the use of composites in more varied application (smart applications, multifunctional issues), one of the actual barrier is their poor electrical and thermal conductivities. In the case of carbon fiber reinforced composites, organic matrix are in charge of the insulating properties of the resulting composite. One of the solutions to enhance conductivities of materials is the use of conductive nanofillers. Improving the electrical and thermal properties of nanofilled polymers has been investigated in several studies. However, studiing the properties of continuous carbon fiber nano-filled composites is less approached. This work tends to fabricate and characterize carbon black and carbon nanotubes nano-filled composites. First of all, special interest was given to the delicate phase of manufacturing. As mentioned before, processing continuous fiber reinforced nanofilled polymers implies issues related to nanofillers agglomeration and inhomogeneous dispersion in the final composite. To resolve these problems, the choice of the thermoplastic (Polyamide6) matrix seemed preferable. In fact, the dispersion of nanofillers was made by twin screw extrusion which is known as one of the most effective agglomeration separation ways. Adding to this, the fabrication method based on Polyamide 6 shects called film stacking, ensure a homogeneous partition at the beginning of the process. SEM observations were performed to localize the nano-particles. It showed that particles penetrated on the fiber zone. In fact, by reaching the fiber zone, the nano-fillers created network connectivity between fibers which means an easy pathway for the current. It explains the noticed improvement of the electrical conductivity of the composites by adding carbon black and carbon nanotube. This test was performed with the 4 points electrical circuit. It shows that electrical conductivity of 'neat' matrix composite passed from 20S/cm to 80S/cm by adding 8wt% of carbon black and to 15S/cm by adding 18wt% of the same nano-filler. For carbon nanotubes, with '2.5wt% the conductivity was around 150S/cm. For the thermal properties, tests based on Joule's effect were performed. The rise of temperature was recorded using IR camera. Results obtained are in agreement with the electrical conductivity ones, showing enhancement of the thermal behavior in presence of nanofillers. Thanks to these results, the use of these composites as a damage-monitoring tool was possible. By the way, the electrical resistance change method was performed. Nanofilled materials showed better sensitivity to damage. Results were compared with classical damage monitoring tools. At the end, several 'smart' applications were tested such as graded functionalities composite and stitched nanofilled materials
Capelle, Emilie. "Conception et fabrication de renforts tissés à base de fibres de lin pour la réalisation de pièces composites à géométries complexes." Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2065.
This work focuses on the weaving and forming of flax based reinforcements. Before being woven, naturalfibres on the form of finite length bundles (~ 30 mm in average for flax) need to be assembled together in a1D continuous product. The use of roving or slivers without twist is rather recommended for compositeapplications. In a first part, this study focuses on the manufacturing and the use of untwisted rovings treatedwith a bonding agent as well as on the weaving process parameters that may influence the mechanicalproperties and the textile characteristics of the woven fabric. Solutions to prevent roving defects duringweaving are proposed. In a second part, this study investigates the ability to develop composite parts with complex geometrieswithout defect. It focuses on the first step of RTM process which consists in forming dry fibrousreinforcements. An experimental approach is used to identify and quantify the defects. The buckling defectcaused by the bending of tows during the preforming step is particularly investigated. Solutions to realize acomplex shape such as a tetrahedron without any defect from flax based woven reinforcements areproposed. With optimized reinforcement architecture, buckling can be prevented. Another solutionconsisting in optimising the process parameters such as the blank holder geometry or the blank holderpressure to prevent the appearance of buckles from commercial fabrics was also investigated with success
Amdouni, Nouredine. "Caractérisation et rôle d'une interphase élastomère au sein de matériaux composites polyépoxy-renfort de verre (particulaire ou fibreux)." Lyon, INSA, 1989. http://www.theses.fr/1989ISAL0064.
Eguémann, Nicolas. "Etude du comportement mécanique de matériaux composites polymère PEEK / renfort fibre de carbone à architecture discontinue en plis." Thesis, Besançon, 2013. http://www.theses.fr/2013BESA2021.