Literatura académica sobre el tema "Composites à Matrice Polymère (CMP)"
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Artículos de revistas sobre el tema "Composites à Matrice Polymère (CMP)":
1
Bréard, J., A. Saouab y G. Bouquet. "Mesure de la perméabilité spatiale d'un renfort tridimensionnel pour matériaux composites à matrice polymère". European Physical Journal Applied Physics 1, n.º 2 (febrero de 1998): 269–78. http://dx.doi.org/10.1051/epjap:1998145.
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Pautrot, S. "Influence des renforts sur l'évolution en température du module d'Young de différents composites à matrice polymère". Annales de Chimie Science des Matériaux 28, n.º 4 (julio de 2003): 43–52. http://dx.doi.org/10.1016/s0151-9107(03)00094-1.
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Zinchenko, О. V., V. D. Ezhova y A. L. Tolstov. "SILICON-CONTAINING OLIGOMERIC AZOINITIATORS IN THE SYNTHESIS OF BLOCK COPOLYMERS". Polymer journal 43, n.º 2 (9 de junio de 2021): 133–42. http://dx.doi.org/10.15407/polymerj.43.02.133.
Resumen
A solvothermal synthetic pathway and functional polymer styabilizers was used for synthesis of fine silver structures of different architecture. Using polyvinylpyrrolidone as a stabilizer silver micronized wires with a diameter of 3,8–4,2 μm and aspect ratio of up to 30 were prepared. XRD technique was applied for qualitative determination of silver metal structures. New thermoresponse composite hydrogels with a structure of semi-IPNs were prepared from cross-linked polyvinyl alcohol, linear highly hydrophilic poly(2-ethyl-2-oxazoline) (PEtOx) and as-synthesized silver micro-sized wires. Effect of a structure and a composition of the polymer matrix, and inorganic anisotropic filler on structure arrangement of composite hydrogels were evaluated by DMA studies. A presence of linear hydrophilic PEtOx and anisotropic metal filler in PVA matrix reduces storage modulus Е’ from 275 to 222–230 MPa and increases loss modulus Е” up to 45,5 MPa at room temperature measurements that partially initiated by poor structuration ability of the composites under high solvation level of polymer matrices. Increasing temperature leads to redistribution of hydrogen bonds network and hybridization of PVA nad PEtOx macrochains and enhances energy dissipation ability of unfilled hydrogel. A filler due to conjugation with amine-functionalized PEtOx chains and its localization closed to a surface of metal supresses polymer-polymer interactions and elasticity parameters of composite matrix drops down. As a result, diffusion and permeability coefficients of composite hydrogels reaches 1,06–1,52·10–9 cm2/s and 0,83–1,09·10-9 g/(cm·s), respectively, that higher in comparison with cross-linked PVA matrices. A presence of hydrogen bonds of different energy in hydrogels provides an appearance of multiple relaxation transitions due to different macrochain mobility in a bulk of polymer matrix. Differences of temperature interval of LCTS for hydrogels were found from analysis Е”(T)/dT (62–70 °С) and Δχ(T)/dT (67–70 °С) dependencies are interrelated with kinetic pecularities of diffusion processes that are able to suppress a phase separation at the temperatures closed to LCTS. Phase inversion processes for hydrogel containing 5 % of PEtOx at LCTS are accompanied by desorption of 32–73 % of sorbate. Moreover, thermoresponsive properties of the hydrogels filled with metallic silver wires are higher than that of the unfilled semi-IPNs.
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Chinesta, Francisco, Amine Ammar y Kunji Chiba. "Mise en forme des composites à matrice polymère renforcée avec des fibres courtes : Vingt ans de simulation numérique". Revue des composites et des matériaux avancés 15, n.º 3 (23 de diciembre de 2005): 323–37. http://dx.doi.org/10.3166/rcma.15.323-337.
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Immonen, Kirsi, Pia Willberg-Keyriläinen, Jarmo Ropponen, Asta Nurmela, Sini Metsä-Kortelainen, Otto-Ville Kaukoniemi y Heli Kangas. "Thermoplastic Cellulose-Based Compound for Additive Manufacturing". Molecules 26, n.º 6 (18 de marzo de 2021): 1701. http://dx.doi.org/10.3390/molecules26061701.
Resumen
The increasing environmental awareness is driving towards novel sustainable high-performance materials applicable for future manufacturing technologies like additive manufacturing (AM). Cellulose is abundantly available renewable and sustainable raw material. This work focused on studying the properties of thermoplastic cellulose-based composites and their properties using injection molding and 3D printing of granules. The aim was to maximize the cellulose content in composites. Different compounds were prepared using cellulose acetate propionate (CAP) and commercial cellulose acetate propionate with plasticizer (CP) as polymer matrices, microcellulose (mc) and novel cellulose-ester additives; cellulose octanoate (C8) and cellulose palmitate (C16). The performance of compounds was compared to a commercial poly(lactic acid)-based cellulose fiber containing composite. As a result, CP-based compounds had tensile and Charpy impact strength properties comparable to commercial reference, but lower modulus. CP-compounds showed glass transition temperature (Tg) over 58% and heat distortion temperature (HDT) 12% higher compared to reference. CAP with C16 had HDT 82.1 °C. All the compounds were 3D printable using granular printing, but CAP compounds had challenges with printed layer adhesion. This study shows the potential to tailor thermoplastic cellulose-based composite materials, although more research is needed before obtaining all-cellulose 3D printable composite material with high-performance.
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Nguyen, Ch N., M. V. Sanyarova y I. D. Simonov-Emel’yanov. "Calculating the composition of dispersion-filled polymer composite materials of various structures". Fine Chemical Technologies 15, n.º 1 (21 de marzo de 2020): 62–66. http://dx.doi.org/10.32362/2410-6593-2020-15-1-62-66.
Resumen
Objectives. The aim is to calculate the composition of dispersion-filled polymer composite materials with different fillers and structures and to highlight differences in the expression of said composition in mass and volume units.Methods. The paper presents the calculation of compositions in mass and volume units for various types of structures comprising dispersion-filled polymer composite materials according to their classification: diluted, low-filled, medium-filled, and highly-filled systems.Results. For calculations, we used fillers with densities ranging from 0.00129 (air) to 22.0 g/cm3 (osmium) and polymer matrices with densities between 0.8 g/cm3 and 1.5 g/cm3 , which represent almost all known fillers and polymer matrices used to create dispersion-filled polymer composite materials. The general dependences of the filler content on the ratio of the filler density to the density of the polymer matrix for dispersion-filled polymer composite materials with different types of dispersed structures are presented. It is shown that to describe structures comprising different types of dispersion-filled polymer composite materials (diluted, low-filled, medium-filled, and highly-filled) it is necessary to use only the volume ratios of components in the calculations. Compositions presented in mass units do not describe the construction of dispersion-filled polymer composite material structures because using the same composition in volume units, different ratios of components can be obtained for different fillers.Conclusions. The dependences of the properties of dispersion-filled polymer composite materials should be represented in the coordinates of the property – content of the dispersed phase only in volume units (vol % or vol. fract.) because the structure determines the properties. Compositions presented in mass units are necessary for receiving batches upon receipt of dispersion-filled polymer composite materials. Formulas are given for calculating and converting dispersion-filled polymer composite material compositions from bulk to mass units, and vice versa.
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Purbasari, Aprilina, Timothius Adrian Christantyo Darmaji, Cindy Nella Sary y Heny Kusumayanti. "Pembuatan dan Karakterisasi Komposit dari Styrofoam Bekas dan Serat Ijuk Aren". METANA 15, n.º 2 (27 de noviembre de 2019): 65–70. http://dx.doi.org/10.14710/metana.v15i2.25794.
Resumen
Komposit merupakan gabungan dari dua atau lebih bahan yang menghasilkan efek sinergis. Komposit dapat dibuat dari polimer sebagai matriks dan serat alam sebagai bahan penguat. Pada penelitian ini komposit dibuat dari styrofoam bekas dan serat ijuk aren. Styrofoam merupakan salah satu jenis polimer yang sulit terdegradasi secara alami, sedangkan serat ijuk aren merupakan serat alam yang mudah diperoleh di Indonesia. Pembuatan komposit dilakukan dengan alat hot press pada berbagai perbandingan massa styrofoam dan serbuk ijuk aren (10:90; 20:80; 30:70; 40:60; dan 50:50). Karakterisasi komposit yang dihasilkan meliputi uji kekuatan mekanik, kerapatan, daya serap air, mikrostruktur, dan gugus fungsional. Komposit mempunyai kekuatan mekanik tertinggi sebesar 90,26 kgf/cm2 pada perbandingan massa styrofoam dan serbuk ijuk aren 30:70. Semakin tinggi kandungan styrofoam dalam komposit maka kerapatan komposit akan semakin meningkat dan daya serap air komposit semakin menurun. Komposit mempunyai struktur yang homogen dan gugus fungsional yang berasal dari styrofoam dan serat ijuk aren.Composite is a combination of two or more materials that produce a synergistic effect. Composite can be made from polymers as matrices and natural fibers as reinforcing agents. In this study, composite were synthesized from used styrofoam and sugar palm fiber. Styrofoam is one type of polymer that is difficult to degrade naturally, whereas sugar palm fiber is a natural fiber that is easily obtained in Indonesia. Composite synthesis was done using hot press equipment at various mass ratio of styrofoam to sugar palm fiber powder (10:90; 20:80; 30:70; 40:60; and 50:50). Characterization of obtained composites covered tests of mechanical strength, density, water absorption, microstructure, and functional groups. Composite had the highest mechanical strength of 90.26 kgf/cm2 at the mass ratio of styrofoam to sugar palm fiber powder of 30:70. The increase of the styrofoam content in composite caused the increase of composite density and the decrease of composite water absorption. Composite had homogeneous structure and functional groups derived from styrofoam and sugar palm fiber.
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Sarraf, Hamid y Ludmila Škarpová. "Effect of Anodic Surface Treatment on PAN-Based Carbon Fiber and its Relationship to the Fracture Toughness of the Carbon Fiber-Reinforced Polymer Composites". Materials Science Forum 567-568 (diciembre de 2007): 233–36. http://dx.doi.org/10.4028/www.scientific.net/msf.567-568.233.
Resumen
The effect of anodic surface treatment on the polyacrylonitrile (PAN)-based carbon fibers surface properties and the mechanical behavior of the resulting carbon fiber-polymer composites has been studied in terms of the contact angle measurements of fibers and the fracture toughness of composites. Results from contact angle measurements revealed that the angle of electrolyte solution largely decreases with increasing current densities of treatments up to 0.4-0.5 A m-2. The results obtained from the evolution of KIC with flexure of the composites as a function of electric current density shown that the KIC of the composite continually increases with increased current densities of the treatments up to 0.5 A m-2, and a maximum strength value is found about 294 MPa cm1/2 at the anodic treatment of 0.5 A m-2. It can be concluded that the anodic surface treatment is largely influenced in the fiber surface nature and the mechanical interfacial properties between the carbon fiber and epoxy resin matrix of the resulting composites, i.e., the fracture toughness. We suggest that good wetting plays an important role in improving the degree of adhesion at interfaces between fibers and matrices of the resulting composites.
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Colunga-Sánchez, Leslie Mariella, Beatriz Adriana Salazar-Cruz, José Luis Rivera-Armenta, Ana Beatriz Morales-Cepeda, Claudia Esmeralda Ramos-Gálvan y María Yolanda Chávez-Cinco. "Evaluation of Chicken Feather and Styrene-Butadiene/Chicken Feather Composites as Modifier for Asphalts Binder". Applied Sciences 9, n.º 23 (29 de noviembre de 2019): 5188. http://dx.doi.org/10.3390/app9235188.
Resumen
In the present work, the evaluation of chicken feather particles (CFP) and styrene-butadiene/chicken feather (SBS-CF) composites as modifiers for asphalt binder is presented. It is well known that elastomers are the best asphalt modifiers, because their thermoplastic behavior assists asphalts in improving the range of their mechanical properties at both low and high temperatures. Nowadays, the use of natural products and byproducts as fillers for polymer matrices has been a matter of research, and the field of asphalt modification is not the exception. Chicken feather particles (CFP) is a waste material whose main component is keratin, which offers remarkable properties. In the present work, CFP was used as a filler of a styrene-butadiene rubber matrix (SBS) with radial structure, to obtain a composite intended as an asphalt modifier. Besides, raw CFP was also tested as an asphalt modifier. Physical, thermal and rheological properties of the modified asphalts were evaluated in order to determine their degree of modification with respect to the original asphalt. The results show that the addition of raw CFP improves some physical properties as penetration and decreases the phase separation; furthermore, the asphalt modified with CFP displayed similar rheological properties to those shown by the asphalt modified with SBS, while some other properties resulted in being even better, like the phase separation, with the advantage that the CFP comes from a natural waste product.
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Koch, Dietmar, Kamen Tushtev, Jürgen Horvath, Ralf Knoche y Georg Grathwohl. "Evaluation of Mechanical Properties and Comprehensive Modeling of CMC with Stiff and Weak Matrices". Advances in Science and Technology 45 (octubre de 2006): 1435–43. http://dx.doi.org/10.4028/www.scientific.net/ast.45.1435.
Resumen
The mechanical properties of ceramic matrix composites (CMC) depend on the individual properties of fibers and matrix, the fiber-matrix interface, the microstructure and the orientation of the fibers. The fiber-matrix interface of ceramics with stiff matrices (e.g. CVI-derived SiC/SiC) must be weak enough to allow crack deflection and debonding in order to achieve excellent strength and strain to failure (weak interface composites WIC). This micromechanical behavior has been intensively investigated during the last 20 years. With the development of CMC with weak matrices (weak matrix composites WMC) as e.g. oxide/oxide composites or polymer derived CMC the mechanical response can not be explained anymore by these models as other microstructural mechanisms occur. If the fibers are oriented in loading direction in a tensile test the WMC behave almost linear elastic up to failure and show a high strength. Under shear mode or if the fibers are oriented off axis a significant quasiplastic stress-strain behavior occurs with high strain to failure and low strength. This complex mechanical behavior of WMC will be explained using a finite element (FE) approach. The micromechanical as well as the FE models will be validated and attributed to the different manufacturing routes.
Tesis sobre el tema "Composites à Matrice Polymère (CMP)":
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Tuloup, Corentin. "Process and structural health monitoring of Polymer-Matrix Composites (PMC) using embedded piezoelectric transducers". Thesis, Compiègne, 2020. https://bibliotheque.utc.fr/Default/doc/SYRACUSE/2020COMP2593.
Resumen
Ce travail novateur étudie l'intérêt d'intégrer des transducteurs piézoélectriques (à base céramique et/ou polymère) au sein de matériaux composites à matrice organique (CMO) pour effectuer une surveillance en temps réel et in-situ de leur processus de fabrication (Process Monitoring PM) ainsi que de leur vie en service (Structural Health Monitoring SHM). Pour ce faire, les transducteurs piézoélectriques ont été intégrés au cœur des empilements fibreux suivant une méthodologie innovante développée au sein de l’équipe de recherche « Matériaux et Surfaces » du laboratoire Roberval. Le système de fabrication par infusion de résine liquide (LRI) utilisé (campagne en PM) ainsi que les échantillons résultants testés mécaniquement (campagne en SHM) ont été multi-instrumentés à l'aide de plusieurs dispositifs de Contrôle Non Destructif (CND : Emission Acoustique (EA), Thermographie Infrarouge (TIR), Corrélation d’Images Numériques (CIN), etc.) afin d’établir des couplages multi-physiques entre les signaux des techniques CND externes et la signature interne (capacité électrique) provenant des transducteurs intégrés au cœur de la matière. En PM, la sensibilité des transducteurs piézocéramiques (PZT) aux diverses étapes clés du processus LRI (passage du front, imprégnation, arrêt de l’injection, transitions physico-chimiques de réticulation et taux de consolidation) réalisé à divers taux de durcisseur ainsi que leur aptitude à la détection de défauts de fabrication ont montré un fort potentiel digne d’une future utilisation à l’échelle industrielle. En SHM, après une vérification de la non-intrusivité des transducteurs à base céramique et polymère intégrés au cœur des échantillons de tests mécaniques, les transducteurs polymères ont permis une évaluation en temps réel de l’état triaxial de déformation et de la perte de rigidité subis par le CMO hôte durant son chargement mécanique. En revanche, malgré un seuil de non fonctionnement (NWT) lié à la fragilité de leur matériau constitutif, les transducteurs piézocéramiques ont montré une forte sensibilité à la détection et au suivi de l’endommagement en temps réel dès lors qu’ils sont positionnésintelligemment vis-à-vis de la sollicitation mécanique. Ces travaux de thèse se sont achevés sur une première tentative visant à transposer les connaissances acquises en PM et SHM des transducteurs piézoélectriques in-situ d'une échelle 2D « laboratoire » à une échelle structurelle 3D plus proche des réalités industrielles. La fabrication multi-instrumentée d’une structure CMO de type raidisseur « Omega » intégrant 14 transducteurs piézoélectriques (PZT ou copolymère P(VDF-TrFE)) et renforcée en épaisseur par un fil en carbone a permis de confirmer les aptitudes PM du PZT précédemment mises en évidence, et a montré une différence entre la manière dont les signaux de capacité électrique du PZT et des copolymères réagissent à l'ensemble du processus de fabricationThis innovative work studies the interest of integrating piezoelectric transducers (ceramic and/or polymer-based) within Polymer- Matrix Composite materials (PMC) to perform real-time and in-situ monitoring of their manufacturing process (Process Monitoring PM) as well as their lifespan (Structural Health Monitoring SHM). To do this, the piezoelectric transducers were integrated into the heart of the fibrous stacks using an innovative methodology developed within the "Materials and Surfaces" research team at the Roberval laboratory. The Liquid Resin Infusion (LRI) manufacturing system used (PM campaign), as well as the resulting samples tested mechanically (SHM campaign), were multi-instrumented using several Non-Destructive Testing devices (NDT: Acoustic Emission (AE), Infrared Thermography (IRT), Digital Image Correlation (DIC), etc.) in order to establish multi-physical couplings between the signals of external NDT techniques and the internal signature (electrical capacitance) coming from the transducers integrated into the heart of the material. In PM, the piezoceramic (PZT) transducers were found to be sensitive to the various key steps of the LRI process (flow front passing, impregnation, end of injection, chemo-physical transitions during curing and associated consolidation rates) achieved at different hardener rates, and able to detect manufacturing defects. These results showed great potential, worthy of future use on an industrial scale. In SHM, after verification of the non-intrusiveness of the ceramic and polymer-based transducers integrated into the heart of the mechanical test specimens, the polymer transducers allowed a real-time evaluation of the triaxial strain state and the rigidity loss experienced by the host PMC during its mechanical loading. However, despite a Non-Working Threshold (NWT) linked to the brittleness of their constitutive material, the piezoceramic transducers have shown a high sensitivity to the detection and monitoring of damage in real-time when they are positioned intelligently with respect to the mechanical stress. These thesis works ended with a first attempt aimed at transposing the knowledge acquired on PM and SHM of in-situ piezoelectric transducers from a 2D “laboratory” scale to a 3D structural one closer to industrial realities. The multi-instrumented manufacturing of an “Omega” stiffener PMC structure integrating 14 piezoelectric transducers (PZT and P(VDF-TrFE) copolymer) and reinforced through-the-thickness by a carbon tuft thread allowed confirming the previously evidenced PM abilities of the PZT, and showed a difference between how the electrical capacitance signals of PZT and copolymers react to the whole manufacturing process
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Chabert, Emmanuelle. "Propriétés mécaniques de nanocomposites à matrice polymère : approche expérimentale et modélisation". Lyon, INSA, 2002. http://theses.insa-lyon.fr/publication/2002ISAL0011/these.pdf.
Resumen
Ce travail de thèse présente une analyse des propriétés mécaniques de nanocomposites à matrice polymère. Il s'agit d'examiner le rôle de chacun des constituants : la matrice, la charge renforçante et l'interphase (particule-matrice, particule-particule). Nous nous sommes tout d'abord attachés à expliciter, sous forme simple et unifiée, l'approche moléculaire développée au laboratoire GEMPPM (" quasi point defect theory ") destinée à décrire le comportement des polymères amorphes (ou matrice) autour de la transition vitreuse. Une méthodologie originale de détermination des différents paramètres physiques a été proposée et validée sur deux homopolymères amorphes (PET, PMMA) et sur un copolymère statistique (P(S-ABu)). Ensuite, nous avons étudié l'effet du greffage du tensioactif sur les propriétés mécaniques des films de latex. La comparaison de systèmes modèles avec tensioactif greffé et non greffé a montré que l'effet du greffage du tensioactif est faible aux petites et grandes déformations. Par contre, la nature du tensioactif peut éventuellement affecter la morphologie de latex structurés plus complexes, et par conséquent, les propriétés mécaniques des films. Enfin, la dernière partie a été consacrée à l'effet de la présence de charges renforçantes sphériques de taille submicronique. Nous avons étudié le rôle de différents paramètres (fraction volumique, nature de la charge (organique ou minérale), interactions renfort/renfort) sur les propriétés mécaniques élastiques. Pour les modéliser, nous avons développé une approche numérique discrète prenant en compte la microstructure et le contact local renfort/renfort et matrice/renfort. En faisant varier les caractéristiques du contact, on peut ainsi rendre compte des différents résultats expérimentaux de part et d'autre du seuil de percolation géométrique. Finalement, l'analyse des propriétés mécaniques en traction a suggéré que le réseau de charges est détruit dès les premiers pour-cent de déformationThis work aims to analyse the mechanical properties of polymer based composites reinforced by spherical nanofillers. The role of each component has been investigated: the polymer matrix, the filler and the interphase (matrix-filler, filler-filler). Firstly, the mechanical behaviour of polymer has been analysed through the molecular approach (“quasi point defect theory”) developped in GEMPPM laboratory. Based on an new formalism, a original method leading to the determination of physical parameters has been proposed. We have then validated this method for various polymers (PMMA, PET and P(S-ABu)). In a second step, the effect of grafted reactive surfactant on mechanical properties of latex films has been investigated. The comparison of self made model systems with grafted and non grafted surfactant has suggested that the grafting of surfactant affects slightly both the small and the large mechanical properties of latex films. On the contrary, the nature of the surfactant might affect the microstructure of complex latex, and in this way their mechanical properties. The last part is devoted to the effect of nanofillers. We have studied the role played by different parameters (concentration, filler nature (organic or mineral), filler/filler interactions) on the elastic mechanical properties. To model these properties, we have developped a discrete numerical approach taking into account the microstructure and the local contact (filler-filler and matrix-filler). The variation of contact caracteristics has thus enabled us to describe the different experimental results below and above the geometric percolation threshold. Finally, the analysis of tensile strain properties has suggested a rupture of the filler network from the first percent of elongation
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Guigon, Camille. "Vieillissement par cyclage thermique de composites interlocks 3D à matrice polymère". Thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2015. http://www.theses.fr/2015ESMA0004.
Resumen
L’introduction des composites dans des pièces structurelles critiques pour les aéronefs représente une réelle rupture technologique et nécessite des études spécifiques afin de maîtriser leur comportement et leur durabilité. Ce travail a pour objectifs de caractériser et de comprendre les mécanismes de vieillissement de composites interlock 3D à fibres de carbone et à matrice polymère lorsqu’ils sont soumis à des cycles thermiques.Dans ce but, un essai de cyclage thermique (-55°C/120°C), dont l’environnement thermique et gazeux est totalement maitrisé, a été mis en place pour le vieillissement d’échantillons composites représentatifs du motif interlock élémentaire. L’analyse des mécanismes de dégradation induits a été réalisée grâce i/ à la mise au point d’une méthode de caractérisation quantitative 3D de l’évolution des microfissures au cours du cyclage, basée sur des observations par microtomographie RX et sur le développement d’une procédure de traitement d’images spécifique, ii/ au développement d’un essai de cyclage thermique in situ synchrotron couplé à une technique de corrélation d’images volumiques 3D, et iii/ à des simulations par éléments finis prenant en compte l’architecture réelle des échantillons à l’échelle mésoscopique et le comportement thermo-viscoélastique de la matrice.Les résultats obtenus mettent en évidence des couplages thermo-chimio-mécaniques complexes,qui s’expriment à travers quatre paramètres influents : le temps (et le nombre de cycles),l’architecture de l’interlock, la ténacité de la matrice et sa sensibilité à la thermo-oxydationThe introduction of composite materials in critical structural parts for aircrafts represents a real technological breakthrough and requires specific studies to understand their behavior and durability. This work aims to characterize and understand the ageing mechanisms incarbon/epoxy 3D interlock composites when they are submitted to thermal cycling.For this purpose, a thermal cycle test (-55°C/120°C), whose heat and gaseous environment istotally mastered, was set up for the ageing of composite samples of elemental interlock pattern dimensions. Analysis of induced degradation mechanisms was achieved by i/ the development ofa 3D quantitative characterization method of the evolution of microcracks during cycling, basedon observations by microtomography RX and the development of a specific image processing procedure, ii/ the development of an in situ thermal cycle test under synchrotron light, coupled to a digital volume correlation technique, and iii/finite elements simulations taking into account the actual mesoscopic architecture of the samples and the thermo-viscoelastic behavior of thematrix.The results reveal complex thermo-chemo-mechanical couplings that are linked to four important parameters: time (and the number of cycles), the interlock architecture, the matrix toughness andits sensitivity to thermo-oxidation
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Pubellier, Pierre. "Influence de charges micrométriques sur le vieillissement de composites à matrice polymère". Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1177/document.
Resumen
La compréhension des phénomènes de vieillissement dans les élastomères réticulés chargés par des particules inorganiques est primordiale pour proposer un critère de fin de vie aux câbles électriques en usage au sein des centrales nucléaires. En effet, la gaine isolante de ces câbles met en jeu une matrice élastomère formulée par différents adjuvants et charges. Une quantité importante de particules inorganiques, du tri-hydrate d’aluminium (ATH), est usuellement introduite au sein de la matrice afin de lui conférer des propriétés anti-feu satisfaisantes. Les particules utilisées sont de taille micrométrique et du fait de la faible surface de contact polymère / charge intrinsèque aux microcomposites, l’ajout d’ATH est supposé n’impliquer aucune modification des mécanismes de vieillissement de la matrice. Or, des travaux récents ont mis en évidence un comportement au vieillissement thermique différent entre une matrice d’EPDM (élastomère à base d’unités éthylène, propylène et diène) chargée par des particules d’ATH micrométriques et la même matrice, sans ATH.L’objectif de cette thèse est de renseigner plus en détail l’effet du vieillissement thermo- et radio-oxydatif sur une matrice d’EPDM chargée par des particules d’ATH et de mieux comprendre les modifications observées. L’influence de paramètres physico-chimiques importants (taux de charges, fonctionnalisation de la surface des charges) sur le comportement en vieillissement sera en particulier abordée. Nous nous sommes, plus précisément, attachés à décrire l’évolution du réseau à l’échelle macromoléculaire, en déterminant les différentes populations du réseau (chaînes élastiquement actives, chaînes pendantes et extractibles) ainsi que la distribution de la densité de réticulation. Ces données ont été obtenues par le biais de la RMN (Résonance Magnétique Nucléaire) du solide.Les résultats de ces expériences montrent une diminution importante de la période d’induction au vieillissement thermo-oxydatif des matrices d’EPDM lors de l’ajout de particules d’ATH dans le réseau. Cet effet dépend fortement de la quantité de charges ATH introduites et de la fonctionnalisation ou non de leur surface. Lors du vieillissement radio-oxydatif, en revanche, aucune modification des cinétiques de vieillissement n’est observée. La confrontation des données issues des deux types de vieillissement suggère une modification des mécanismes d’amorçage de l’oxydation, dans les réseaux d’EPDM, lorsque ces derniers sont chargés par des particules d’ATH. Le rôle des interfaces charge / matrice semble donc déterminant dans ces modificationsA deep understanding of the ageing behaviour within cross-linked elastomers filled by inorganic particles is a key feature to propose a criterion for the end of life of electric cables in nuclear power plants. Indeed, materials used for wire insulation are usually composed of rubbers designed with several adjuvants and fillers. A significant amount of inorganic particles, such as aluminium trihydrate (ATH), is usually incorporated with the polymer matrix in order to achieve satisfactory fire-retardant properties. The ATH particles used are characterized by a micrometric-size and due to the weak polymer / filler contact area involved in such composites, the ageing mechanisms of the polymer matrix are expected to be essentially unchanged compared to the ones involved in the unfilled matrix. However, recent studies pointed out some differences in the thermal-ageing mechanisms between a cross-linked EPDM rubber (elastomer based on ethylene, propylene and diene units) filled by micrometric ATH (aluminium trihydrate) particles and the corresponding unfilled cross-linked EPDM.In that respect, this work aims at investigating the extent of generality of the above-mentioned filler effect on both thermo- and radio-oxidative ageing behaviour of an EPDM matrix filled by ATH particles. In particular, the influence of both filler content and filler surface functionalization is investigated. A special attention was paid to the evolution of the network at the macromolecular scale by determining the fraction of the various network components (elastically active chains, dangling chains and extractibles) as well as the cross-link density distribution. Such information have been derived using solid-state NMR (Nuclear Magnetic Resonance).The results obtained evidence a significant decrease of the thermal-ageing induction period for the EPDM network filled by ATH particles. This effect display a strong dependence with the amount and the surface functionalization of the ATH particles. However, no modifications of the oxidation kinetics may be observed under radio-chemical ageing. The comparison between the results suggests a possible modification of the oxidation initiation mechanisms within EPDM networks filled by ATH particles. Therefore, interfacial areas should play a great role in the observed modifications
5
Droulas, Jean-Luc. "Chimie interfaciale des systèmes métal - polymère". Lyon 1, 1992. http://www.theses.fr/1992LYO10082.
Resumen
L'etude des premiers stades de la metallisation de differents polymeres a ete effectuee par evaporation thermique et pulverisation ionique du metal in situ. La spectroscopie esca et la microscopie afm ont permis d'etudier la chimie interfaciale et la morphologie du depot. L'evaporation d'or (sur ps et pet) et d'aluminium (sur ldpe, pp, ps, pet, peek, pva et ldpe traite par plasma micro-ondes d'oxygene) induisent respectivement la formation d'interfaces chimiques instables, et l'apparition de complexes interfaciaux de transfert de charge du type carbone-oxygene-aluminium (sauf avec le ldpe et le pp). La pulverisation ionique d'or (sur ps et pet) et d'aluminium (sur ldpe, ps, pet et ldpe traite par plasma micro-ondes d'oxygene), montrent la cassure de liaisons c-c et/ou c-h des chaines polymeriques, et la constitution d'interfaces chimiques (liaisons metal-carbone et metal-oxygene-carbone) selon une interaction due a l'energie des atomes incidents. Dans les deux cas, evaporation et pulverisation, un modele d'interaction est propose (avec les polymeres insatures et oxygenes), base sur les proprietes acido-basiques (au sens de lewis) des deux partenaires. Les etudes afm des surfaces apres depot ont revele une progression du film en ilots d'atomes volumineux et disperses par evaporation, tandis que la pulverisation donne lieu a une plus grande densite surfacique en ilots metalliques
6
Dalmas, Florent. "Composites à matrice polymère et nano-renforts flexibles : propriétés mécaniques et électriques". Phd thesis, Grenoble INPG, 2005. http://tel.archives-ouvertes.fr/tel-00012111.
Resumen
Cette thèse porte sur la mise en œuvre, la caractérisation microstructurale et l'étude des propriétés macroscopiques de matériaux nanocomposites à matrice polymère (un latex filmogène) renforcée par des nanofibres flexibles à haut facteur de forme. En étudiant deux types de renforts (les nanotubes de carbone et les nanofibrilles de cellulose) et en utilisant deux procédés différents pour l'élaboration des composites, ce travail a permis de mieux comprendre le rôle que jouent les enchevêtrements entre nanofibres et la nature de leurs interactions dans ce type de matériaux. Les propriétés mécaniques aux faibles et grandes déformations, et, dans le cas des renforts nanotubes de carbone, les propriétés élecriques ont été analysées. Une approche de modélisation basée sur la discrétisation des fibres dans un volume représentatif, a permis de discuter l'influence de la tortuosité des fibres et des propriétés électriques des contacts entre fibres sur la percolation électrique.
7
Frada, Jean-Michel. "Contribution à l'étude des multimatériaux acier-polymère-acier : caractérisation chimique et structurale des interphases dans des systèmes métal-oxyde-polymère". Nancy 1, 1992. http://docnum.univ-lorraine.fr/public/SCD_T_1992_0408_FRADA.pdf.
Resumen
Le matériau qui constitue le support de notre étude est un composite à structure sandwich acier-polymère-acier, élaboré par SOLLAC, dont la propriété essentielle est l'amortissement des vibrations sonores. Ce composite procure un confort acoustique recherché par l'industrie automobile. Afin d'obtenir un assemblage performant, il faut maîtriser une famille de paramètres dont le plus important est peut-être la durabilité du joint. Il ressort clairement de nos travaux que les produits acides de la dégradation thermique des polymères comme EVA (copolymère thermoplastique polyéthylène-acétate de vinyle), engendrent des réactions avec les métaux ou leurs oxydes. Les produits de réaction les plus caractéristiques sont des "chélates", acétates métalliques. La stabilité de ces phases devient alors le facteur déterminant la durabilité du composite. Les phases insolubles dans l'eau comme l'oxyacétate de chrome peuvent expliquer le rôle favorable du chrome sur l'adhérence métal-polymère, en milieu humide. A contrario, les sels solubles comme l'acétate de fer semblent être à l'origine des décohésions rapides observées. Des traitements du polymère (ajouts basiques comme l'urée) ou de l'acier (nickelage) parviennent à modifier ces réactivités. Les structures des complexes déterminées par diffraction X suggèrent l'existence d'interactions entre le complexe et les métaux ou leurs oxydes, et entre le complexe et les polymères.
8
Lafabrier, Aurore. "Etude de l'adhérence de revêtements poudre appliqués sur substrats composites à matrice polymère". Thesis, Toulon, 2014. http://www.theses.fr/2014TOUL0017.
Resumen
Sur de nombreuses pièces et structures, la peinture garantit une protection de surface et assure l'esthétique du produit final. Cependant, l'arrivée de nouvelles directives visant à réduire les sources de rejets majoritaires de Composés Organiques Volatiles (COV) incite les industriels à s'orienter vers des technologies alternatives aux peintures solvantées classiques, telles que les revêtements poudres. Dans le cas d'un substrat non-conducteur thermosensible, cette substitution implique de développer de nouvelles méthodes de mise en œuvre et d'en optimiser les paramètres.Ce travail de thèse vise à maîtriser l'adhérence et à comprendre les phénomènes d'adhésion de peintures poudre sur substrats composites à matrice organique, d'un point de vue physico-chimique. Notre travail s'est articulé autour d'une peinture poudre et de deux substrats composites dont l'un possède une matrice thermodurcissable (époxy) et l'autre une matrice thermoplastique (PEEK).Dans un premier temps, nous avons analysé l'influence des conditions de mise en œuvre sur l'interface substrat époxy/revêtement, afin de déterminer quel procédé favorise le plus l'adhérence entre la méthode "fond de moule" et l'application directe. Nous nous sommes, ensuite, intéressés à la durabilité de ces systèmes revêtus lors d'un vieillissement hygrothermique. Enfin, nous avons étudié l'effet des traitements plasmas atmosphérique et basse pression sur l'adhérence entre le revêtement poudre et le substrat à matrice PEEKOn many products and structures, the painting ensures surface protection and provides aesthetic of final product. However, the new guidelines to reduce the main release's sources of Volatile Organic Compounds (VOCs) incite the industrials to use alternative to usual solvent-based paints such as powder coatings. In the case of non-conductive and heat-sensitive substrate, this substitution involves the development of new processes and the optimization of their parameters.This thesis is about controlling adhesion and understanding the adhesion of powder coatings on organic matrix composites substrates, on a physico-chemical point of view. Our work focus on a powder coating and two substrates, one containing thermosetting resin (epoxy) and the other a thermoplastic resin (PEEK) .As a first step, we analyzed the influence of the characteristic of the process on the epoxy substrate/coating interface to determine which one promotes the best adhesion between the "in mold-coating" and direct application. Then we studied the durability of these coated systems in a hydrothermal aging. Finally, we studied the effect of atmospheric plasma treatment and low pressure plasma treatment on the adhesion between powder coating and PEEK matrix substrate
9
Boudenne, Abderrahim. "Étude expérimentale et théorique des propriétés thermophysiques de matériaux composites à matrice polymère". Paris 12, 2003. https://athena.u-pec.fr/primo-explore/search?query=any,exact,990002111180204611&vid=upec.
Resumen
Ce travail porte sur l’étude expérimentale et théorique des propriétés thermophysiques de composites constitués de charges d’aluminium (Al) et de cuivre (Cu) dispersées dans une matrice polypropylène (PP). Le travail présenté est consacré dans un premier temps à l’amélioration d’un dispositif expérimental de mesure simultanée de la conductivité et de la diffusivité thermique. La caractérisation d’échantillons connus nous a permis de valider cette méthode de mesure. Par la suite, différents composites PP/Cu et PP/Al ont été réalisés pour diverses concentrations et granulométries de charges. Des mesures de chaleur spécifique, de conductivité et de diffusivité thermique de ces composites ont permis de mettre en évidence l’effet de la taille et de la concentration en charges sur leur comportement thermophysiqueThis work is devoted to the experimental and theoretical study of thermophysical properties of polymer matrix composites containing aluminium (Al) and cooper (Cu) powders dispersed in a polypropylene (PP) matrix. The first objective was the improvement of a simultaneous thermal conductivity and diffusivity measurement method. The characterisation of reference samples allowed the validation of the measurement protocol. Thereafter, several PP/Cu and PP/Al composites were achieved for various concentrations and particles sizes. Measurements of specific heat, thermal conductivity and diffusivity of theses composites showed the effect of concentration and particle size effect on the thermophysical behaviour of these composites
10
Lachi, Mohand Tayeb. "Fluage en torsion de composites à renforts filamentaires et matrice polymère : influence de l'humidité". Lyon 1, 1992. http://www.theses.fr/1992LYO10237.
Resumen
Cette etude se situe dans le contexte general de la caracterisation du comportement en cisaillement de composites a fibres de carbone ou verre et matrice polymere. Les eprouvettes parallelepipediques a fibres longitudinales ou transverses sont soumises a des essais de fluage en torsion aux differents taux d'humidite relative 0, 60, 80 et 96% a la temperature constante de 60#c. Une etude introductive rappelle le probleme de la caracterisation des proprietes de cisaillement et les bases theoriques du probleme de torsion. Les phenomenes d'absorption d'eau des composites a matrice organique sont egalement presentes. La conception et la realisation des machines d'essais de fluage en torsion simples peu encombrantes et de cout de fabrication raisonnable sont ensuite decrites. Ces machines permettent d'effectuer des essais en parallele dans les enceintes de conditionnement. Les cinetiques d'absorption d'eau sont modelises a priori par la loi de fick. Le choix d'un barreau composite de section droite carree a fibres longitudinales ou transverses permet en principe de determiner les diffusivites effectives suivant les trois directions x, y et z de l'eprouvette. Trois composites a matrice polymere ont ete etudies: deux materiaux a base de fibres de verre e unidirectionnelles et tissees et un materiau a fibres de carbone unidirectionnelles. L'absorption d'eau suivant la direction des fibres est en general plus rapide que suivant la direction transverse, on caracterise ainsi l'anisotropie de la diffusion macroscopique des composites unidirectionnels. De plus les diffusivites experimentales du composite renforce par un tissu d verre equilibre sont pratiquement independantes des humidites relatives et de l'orientation chaine et trame. Les essais de fluage d'echantillons satures, testes a differents couples, permettent l'etude de la variation de la complaisance de cisaillement dans le temps en fonction de la quantite d'eau absorbee. Les courbes de complaisance les plus marquantes sont celles des echantillons verre/epoxyde conditionnes a 80 et 96% hr ou l'on met en evidence la grande sensibilite du comportement en cisaillement a la concentration en eau. En outre l'endommagement observe des echantillons a fibres longitudinales se traduit par des fissures longitudinales suivant la direction des fibres alors que les transverses se rompent en traction transverse. Enfin, les courbes maitresses obtenues et la courbe d'evolution du facteur de glissement en fonction de la concentration en eau permettent raisonnablement de prevoir le comportement du materiau dans un large domaine temps-concentration en eau
Libros sobre el tema "Composites à Matrice Polymère (CMP)":
1
Approaches to polymer-derived CMC matrices. [Washington, DC]: National Aeronautics and Space Administration, 1992.
2
Approaches to polymer-derived CMC matrices. [Washington, DC]: National Aeronautics and Space Administration, 1992.
3
United States. National Aeronautics and Space Administration., ed. Approaches to polymer-derived CMC matrices. [Washington, DC]: National Aeronautics and Space Administration, 1992.
4
United States. National Aeronautics and Space Administration., ed. Approaches to polymer-derived CMC matrices. [Washington, DC]: National Aeronautics and Space Administration, 1992.
5
Kudinov, V. V., N. V. Korneeva y I. K. Krylov. Effect of components on the properties of composite materials. Nauka Publishers, 2021. http://dx.doi.org/10.7868/9785020408654.
Resumen
Methods for the creation and characteristics of composite materials reinforced with carbon, aramid and UHMWPE-fibers based on polymer matrices are considered. The properties of more than 50 composite materials are given. Technologies for their production from wound nonwoven and woven fiber reinforcements are proposed, with regulation of activation, composition and arrangement of components in the material. Experimental methods for studying polymer com- posites, such as wet-pull-out (W-P-O), full-pull-out (F-P-O) and impact break (IB) have been developed. It allows one to study the interfacial interaction of components during the creation of CM, regulate the activation of fibers by non-equilibrium low-temperature plasma and fluo rination, and analyze mechanisms of deformation and destruction of CM, in statics and upon impact with the help of uniform universal samples. Monograph – reference book is intended for scientific and engineering staff, teachers, stu- dents, graduate students, and inventors involved in the development, production and use of poly mer composite materials.
Capítulos de libros sobre el tema "Composites à Matrice Polymère (CMP)":
1
Zhang, Weigang, Changming Xie, Min Ge y Xi Wei. "C/C-ZrB2-ZrC-SiC Composites Derived from Polymeric Precursor Infiltration and Pyrolysis Part I". En MAX Phases and Ultra-High Temperature Ceramics for Extreme Environments, 413–34. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-4066-5.ch013.
Resumen
Two-dimensional C/C-ZrB2-ZrC-SiC composites with three phases of ultra high temperature ceramics (UHTCs) are fabricated for the first time using blending pre-ceramic polymeric precursors through the traditional polymer infiltration and pyrolysis (PIP) technique, in which a porous carbon fiber reinforced pyrolytic carbon (C/C) with a porosity of about 60% is prepared as preforms. The fabricated composite possesses a matrix of 20ZrB2-30ZrC-50SiC, which is obtained by co-pyrolysis of three pre-ceramic polymers solution in xylene with certain molar ratios. Pyrolysis of these ZrB2-ZrC-SiC pre-ceramic precursors is studied with XRD characterization of the residual solids. The gas phase products are analysized with an on-line GC-MS-FTIR coupling technique, which confirms the formation of crystalline ZrC and ZrB2 from these precursors at temperatures above 1400°C. Possible mechanisms of pyrolysis and formation of pure ZrB2 from the precursors with various B/Zr molar ratios are suggested. The densification process and microstructures of the fabricated composite are studied. It is found that a composite with a bulk density of 2.06 g/cm3 and open porosity of 9.6% can be obtained after 16 PIP cycles. The formed matrix exhibits homogeneous dispersion of three matrix ceramics without any oxide impurities, i.e., the nano sized ZrB2 and ZrC particles dispersed in a continuous SiC ceramic with clean crystalline boundaries and particle dimensions less than 200 nm. No erosion or interface reaction occurs upon the carbon fiber reinforcement, which therefore avoids a dramatic deterioration of mechanical strength of carbon fiber and the composite. Improvement of PIP benefits from two aspects; firstly, the dense pyrolytic carbon interphase deposited on fiber surface by CVI serves as barrier coating and secondly, pyrolysis of the novel organic polymeric precursors does not release corrosive by-products such as hydrogen chloride.
Actas de conferencias sobre el tema "Composites à Matrice Polymère (CMP)":
1
Shue, Bruce, Alfonso Moreira y George Flowers. "Review of Recent Developments in Composite Material for Aerospace Applications". En ASME 2009 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/detc2009-87847.
Resumen
Advanced materials are a key element in the development of modern aerospace vehicles and composites are one of the most promising types of such materials. They tend to be significantly lighter than their metal counterparts, while possessing impressive strength and performance characteristics. This paper describes recent work and developments in three major types of composite materials — polymer matrix composite (PMC), metal matrix composite (MMC), and ceramic matrix composite (CMC). Recent work in nanocomposites, which is particularly applicable to polymer matrix and metal matrix composites is also presented and discussed. In addition, some recent work in composite material damping is discussed and a modeling strategy for amplitude dependent damping is developing based upon heuristic modeling considerations and experimental testing results.
2
Rahman, Mosfequr, F. N. U. Aktaruzzaman, Saheem Absar, Aniruddha Mitra y Awlad Hossain. "Finite Element Analysis of Polyurethane Based Composite Shafts Under Different Boundary Conditions". En ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-37753.
Resumen
Depending on the type of matrix materials, composites can be broadly divided into three different major classifications: Organic-matrix composites (OMC), metal-matrix composites (MMC), and ceramic-matrix composites (CMC). OMC can be further sub-classified into polymer-matrix composites (PMC) and carbon-matrix composites or carbon-carbon composites. In this paper the main objective is to focus on polyurethane based PMC composites. Polyurethane is one of the widely used polymer matrix materials. It has diversified applications, easily available and cheap. In this computational study a composite shaft with a core made of matrix material completely wrapped around by a woven fiber cloth with a very strong bonding between core and fibers is considered. Three different types of woven fibers: fiber glass, Kevlar 49, and carbon fibers, are considered. A woven fabric is the interlocking or weaving of two unidirectional fibers. This configuration is often used to produce curve surfaces because of the ease with which it could be placed on and conform to curved surfaces. Authors had fabricated these three composites in their in-house laboratory. They had also experimentally measured the mechanical properties of these composites using 3-point bending test which already been published. In this current study finite element analyses has been performed for the modeling of the static response of these three different polyurethane based composite shafts as fiber glass reinforced polyurethane epoxy, carbon fiber reinforced polyurethane epoxy, and Kevlar fibers reinforced polyurethane epoxy for three different boundary conditions. These three boundary conditions are simply supported, cantilever, both end fixed types with bending loads applied at the middle for simply supported case and distributed load along the length of the shaft for the last two types of boundary conditions. A three dimensional model of the composite beam has been implemented in this study using SolidWorks. A finite element commercial software ANSYS is used to investigate the stress response and deformation behavior of the model geometry for these three polyurethane based composite shafts for these three boundary conditions. A twenty node three dimensional element has been implemented for the finite element formulation of the modeled geometry such that it is applicable for the analysis of a layered composite structure, while providing support for linear, large rotation, and large strain nonlinear loading conditions. Convergence has also been ensured for various mash configurations in this work.
3
Wilkinson, Michael P. y Marina B. Ruggles-Wrenn. "Mechanical Properties and Fatigue Behavior of 2D Woven PMC and Unitized Composite Airframe Structures at Elevated Temperature". En ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-65763.
Resumen
Airframe structures and components on many existing and future Air Force aerospace systems require operation in elevated temperature. Examples include hypersonic vehicle airframes, engine related components (such as engine ducts, engine vanes, and exhaust flaps), and hot trailing edges of B-2 and C-17 wings. Material systems that show improved fatigue performance, excellent thermal resistance, and damage tolerance are prime candidate materials for potential air vehicle structural components. Polymer matrix composites (PMCs) and ceramic matrix composites (CMCs) are two types of composites used in aircraft structures subjected to high temperatures. The polymer matrix in most PMCs cannot withstand the temperatures required for many aerospace structural applications. Therefore, either improvements in temperature capability of polymer matrix materials or developing novel thermal protection systems are desired for elevated temperature applications. Any new material system intended for aerospace applications must be studied and tested to verify that the mechanical properties are sufficient for use in the operating environments. This study investigated the mechanical properties and tension-tension fatigue behavior of two newly developed material systems for use in structures subjected to elevated temperatures, namely a 2D weave PMC and a 2D weave unitized composite (or PMC/CMC, consisting of a PMC co-cured with a CMC layer to act as a thermal barrier). These two material systems are two of three new composites developed under contract through the Air Force Research Laboratory (AFRL) and investigated during a master’s thesis research program at the Air Force Institute of Technology (AFIT) [1]. The 2D PMC investigated in this effort consisted of an NRPE (a high-temperature polyimide) matrix reinforced with carbon fibers. The fiber architecture of the PMC was an 8 harness satin weave fiber fabric. The PMC portion of the unitized composite had the same constituent properties and weave as the aforementioned 2D PMC. The CMC layer consisted of a zirconia-based matrix reinforced with an 8 harness satin weave quartz fiber fabric. For both material systems (PMC and PMC/CMC), material properties were investigated for both on-axis [0°/90°] and off-axis [±45°] fiber orientations. Tensile properties were evaluated at (1) room temperature and (2) with one side of the specimen at 329 °C and the other side exposed to ambient air. Tension-tension fatigue tests were conducted at elevated temperature at a frequency of 1.0 Hz with a ratio of minimum stress to maximum stress of R = 0.05. Fatigue run-out for this effort was defined as 2×105 cycles. Elevated temperature had little effect on the tensile properties of both material systems with the 0°/90° fiber orientation; however, specimens with the ±45° fiber orientation exhibited a significant increase in failure strain at elevated temperature. The ultimate tensile strength (UTS) of the 2D PMC with the ±45° fiber orientation decreased slightly at elevated temperature, but the UTS of the unitized composite with ±45° fiber orientation showed no significant change. The unitized composite did not exhibit an increase in tensile strength and stiffness compared to the 2D PMC. However, the 2D PMC with ±45° fiber orientation produced significantly greater failure strain. The 2D PMC showed slightly better fatigue resistance than the unitized composite with the 0°/90° fiber orientation. For the ±45° fiber orientation, the fatigue limit for the 2D PMC was approximately two times greater than that for the unitized composite. Microstructural investigation of tested specimens revealed delamination in the 2D PMC and very severe delamination in the unitized composite.
4
Nixon, Jason R., Inna Lempert, Hyunjo Choi, Jeremy McFarlane y David I. Bigio. "Characterization of Material Properties for Multi-Scale Polymer Composites Extruded From Straight and Divergent Die Geometries Using Various Filler Concentrations". En ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-51919.
Resumen
The addition of nano-scale and micro-scale fillers has been proven to increase tensile and thermal properties in polymer composites. Orientation of high aspect fillers, however, has not been studied before despite being crucial to altering physical properties. When fibers are included during extrusion, they tend to align in the direction of the flow. This phenomena leads to longitudinal improvements in mechanical properties, and thus provides great benefits in some applications; however, it is beneficial to have improved properties in the transverse direction as well. Therefore, it is crucial to study reorientation phenomena in composites. The purpose of this experiment is to study property enhancement resulting from fiber structure. The material properties are compared for the range of weight percentages of fillers. This is done for the purpose of finding an ideal fill concentration. Two dies are used to study different orientation distributions: straight and divergent. Thermal and tensile properties and optical micrographs are analyzed and compared. Composites were processed on a Coperion ZDSK-28mm co-rotating, fully-intermeshing, twin-screw extruder. Polybutylene terephthalate (PBT) was used as the polymer matrix. 0 W% to 2 W% multi-walled carbon nanotubes (CNTs) and 0 W% to 30 W% carbon microfibers (CMFs) were used as fillers. Preliminary results showed a clear trend in increased tensile strength of the composite with the increase of concentration of CMFs and CNTs in the slit die up to 25 W% CMF. After 25 W% CMF, however, there was a depreciation in properties. Similarly, thermal conductivity results have shown a clear peak at 25 W% CMF with 30 W% showing a decrease in thermal properties. Preliminary results for the divergent die showed that, with addition of carbon microfibers to the polymer matrix, thermal properties of the composite increased up to 15 W%, then dropped and increased again as more CMFs were added. In addition, on average, material extruded through the divergent die showed better results of thermal conductivity than that extruded through the slit die. This indicates that when using a diverging die, fiber become oriented perpendicular in relation to the direction of the flow, thus improving heat flow in the transverse direction.
5
Wurtinger, H. y A. Mühlratzer. "Cost Effective Manufacturing Methods for Structural Ceramic Matrix Composite (CMC) Components". En ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/96-gt-296.
Resumen
MAN Technologie AG has been engaged in the field of ceramic matrix composites (C/SiC, SiC/SiC) for approximately 10 years. Two manufacturing methods have been developed with respect to economical series production: - Chemical Vapour Infiltration Process (CVI) with temperature and pressure gradients - Liquid Polymer Impregnation (LPI) and Pyrolysis The advantage of these methods is an essential reduction of process time compared to the conventional isothermal-isobaric CVI method, with equivalent material performance. The main material characterization data, such as strength/strain, thermal shock, dynamic fatigue and high temperature behaviour are described. Several components under development or in low volume preseries production are presented.
6
Miller, Robert J. "Designing With High Temperature Composites". En ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-0149.
Resumen
Abstract Actual and potential composite applications in commercial and military aircraft gas turbine engines range from low temperature graphite/polymer matrix composite (PMC) components at the front of the engine, such as, fan blades, vanes, struts and cases, to high temperature ceramic matrix composite (CMC) turbine, combustor, augmentor, and nozzle components. Currently the “building block” approach is primarily used in the development of composite components for gas turbine engines. Critical issues associated with the design of composite structures for both commercial and military aircraft gas turbine engines are defined. Critical structural components for both commercial and military gas turbine engines are designed to meet strict safety-of-flight requirements established by the FAA and the Air Force/Navy, respectively. Key design requirements established for damage tolerance and durability are emphasized.
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Kumar, Rajesh S. "Micromechanics Approach for the Overall Elastic Properties of Ceramic Matrix Composites Incorporating Defect Structures". En ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-16056.
Resumen
Abstract Initial mechanical behavior of Ceramic Matrix Composites (CMCs) is linear until the proportional limit. This initial behavior is characterized by linear elastic properties, which are anisotropic due to the orientation and arrangement of fibers in the matrix. The linear elastic properties are needed during various phases of analysis and design of CMC components. CMCs are typically made with ceramic unidirectional or woven fiber preforms embedded in a ceramic matrix formed via various processing routes. The matrix processing of interest in this work is that formed via Polymer Impregnation and Pyrolysis (PIP). As this process involves pyrolysis process to convert a pre-ceramic polymer into ceramic, considerable volume shrinkage occurs in the material. This volume shrinkage leads to significant defects in the final material in the forms of porosity of various size, shape, and volume fraction. These defect structures can have a significant impact on the elastic and damage response of the material. In this paper, we develop a new micromechanics modeling framework to study the effects of processing-induced defects on linear elastic response of a PIP-derived CMC. A combination of analytical and computational micromechanics approaches is used to derive the overall elastic tensor of the CMC as a function of the underlying constituents and/or defect structures. It is shown that the volume fraction and aspect ratio of porosity at various length-scales plays an important role in accurate prediction of the elastic tensor. Specifically, it is shown that the through-thickness elastic tensor components cannot be predicted accurately using the micromechanics models unless the effects of defects are considered.
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Nishio, Kozi, Ken-ichiroh Igashira, Koji Take y Takeshi Suemitsu. "Development of a Combustor Liner Composed of Ceramic Matrix Composite (CMC)". En ASME 1998 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/98-gt-104.
Resumen
The Research Institute of Advanced Materials Gas-Generator (AMG), which is a joint effort by the Japan Key Technology Center and 14 firms in Japan, has, since fiscal year 1992, been conducting technological studies on an innovative gas generator that will use 20% less fuel, weigh 50% less, and emit 70% less NOx than the conventional gas generator through the use of advanced materials. Within this project, there is an R&D program for applying ceramic matrix composite (CMC) liners to the combustor, which is a major component of the gas generator. In the course of R&D, continuous SiC fiber-reinforced SiC composite (SiCF/SiC) was selected as the most suitable CMC for the combustor liner because of its thermal stability and formability. An evaluation of the applicability of the SiCF/SiC composite to the combustor liner on the basis of an evaluation of its mechanical properties and stress analysis of a SiCF/SiC combustor liner was carried out, and trial SiCF/SiC combustor liners, the largest of which was 500mm in diameter, were fabricated by the filament winding and PIP (polymer impregnation and pyrolysis) method. Using a SiCF/SiC liner built to the actual dimensions, a non-cooling combustion test was carried out and even when the gas temperature was raised to 1873K at outlet of the liner, no damage was observed after the test. Through our studies we have confirmed the applicability of the selected SiCF/SiC composite as a combustor liner. In this paper, we describe the present state of the R&D of a CMC combustor liner.
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Krishnan, Srivatsava, Prasant Vijayaraghavan y Vishnubaba Sundaresan. "Characterization of Mechanoluminescent Composites and Their Applications for SHM of Polymer Composites". En ASME 2015 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/smasis2015-9078.
Resumen
Mechanoluminescence (ML) is a property of inorganic and organic materials that describes the emission of light due from the application of force. Inorganic crystals (mostly phosphors) and certain organic macromolecules exhibit elastico-ML and are a natural fit for structural health monitoring (SHM) of composite structures. Composites with particulate ML crystals enable the visualization of stress distribution over a plane and over contoured surfaces in a spatially continuous manner. Imaging ML composites with affordable high-resolution imaging methods further enables the creation of high-resolution validation method for computational methods. Also, with the embedding of suitable photo-detectors for signal detection, the need for additional wiring, sensor electronics and high-level electronics is eliminated. In this conference proceedings technical publication, the application of commercially available ZnS:Cu, Mn phosphors for SHM of polymer composites will be presented via experimental and structural simulation. Results demonstrate the dependence of intensity of elastico-ML (in cd/cm2) on strain rate, strain and composition (w/w of ML particulates). The experiments show methods to fabricate elastic coupons of phosphors in polydimethylsiloxane (PDMS) and subsequent methods for application in SHM. The structures are excited at 5Hz to 17.5Hz to develop empirical relationships between strain rate and EML intensity and it is shown that the intensity increases nonlinearly with the magnitude of stress/strain rate. A range of stresses transferred to the EML particles by the PDMS matrix is also numerically predicted. The numerical simulations show the importance of interfacial binding in the transfer of stress and subsequent EML emission. These results also provided a basis for validation and improvement of structural simulation models.
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Hiromatsu, M., T. Yamamura, T. Chikata, T. Sekido, S. Ohama, H. Miyagawa, I. Murakami y S. Seki. "Research and Development Status of Advanced Material Gas-Generator (AMG) Project". En ASME 1995 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/95-gt-287.
Resumen
Advanced Material Gas-Generator (AMG) R&D Project was initiated in 1993 as a ten year’s program with a joint investment from Japan Key Technology Center and fourteen participating domestic companies. The program objective is to establish basic key technologies for next generation gas-generator using advanced materials, which should have the features of significantly low fuel consumption with reduced weight and size, and should be environmentally acceptable, toward the realization of future industrial, marine and aerospace gas-turbine. The R&D themes in this project cover advanced gas-generator conceptual study, advanced material and structures, innovative system and control, and advanced components technologies such as low NOx combustor. Each R&D theme is underway toward achieving the program goal. The 1st conceptual drawing of the advanced material gas-generator is completed as the result of the conceptual study. PMC (Polymer Matrix Composites), MMC (Metal Matrix Composites), CMC (Ceramic Matrix Composites) and TiAl (Titanium-Aluminide) are considered as the candidate material for the advanced material gas-generator. This paper introduces the outline of this project, and describes the status of conceptual study and each R&D themes.