Tesi: "Composites"

1

Thanomsilp, Chuleeporn. "Toughening composites for liquid composite moulding". Thesis, Queen Mary, University of London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390838.

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2

Mahmoud, Bassam. "Modélisation d'impacts sur des stratifiés composites unidirectionnels et hybrides". Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30212.

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Les structures aéronautiques sont aujourd’hui largement réalisées à partir de matériaux composites, permettant ainsi d’en diminuer la masse. L’impact sur structure composite est une des sources de dommage la plus courante et la plus pénalisante. L’objectif de cette thèse est de développer un modèle prédictif d’impact sur stratifiés unidirectionnels de faible épaisseur afin, dans un premier temps, de mieux comprendre les mécanismes d’endommagement mis en jeu et, dans un deuxième temps, de pouvoir proposer des pistes d’amélioration de la tenue de ces structures. La première étape de ces travaux a consisté à développer un modèle éléments finis explicite de stratifiés composite unidirectionnel, en s’appuyant sur les travaux d’impact sur pale d’hélicoptère réalisés par F. Pascal. Ainsi, un nouvel élément capable de représenter le comportement à l’impact des plis unidirectionnels a été formulé. Le comportement des paquets de fibres est représenté par des éléments barres stabilisés grâce à des éléments 2D spécifiques. La dégradation de ces éléments est pilotée par des lois d’endommagement déduites d’observations expérimentales. La stratégie de modélisation proposée a été identifiée sur la base d’essais expérimentaux pour deux matériaux : T700/M21 et HTA7/913. Les résultats donnés par le modèle ont ensuite été validés par une comparaison avec des essais d’impact à basse vitesse. Enfin, dans le but d’optimiser la tenue des stratifiés, des impacts à basse et moyenne vitesse sur des stratifiés hybrides unidirectionnels/tissus composites ont été étudiés expérimentalement et numériquement grâce à la stratégie de modélisation proposée
Today, composite materials are largely used in the manufacturing of aeronautical structures, in order to lighten their weight. Impact on composite structures is one of the most detrimental loading. The present study aims to develop a predictive modelling of impacts on thin unidirectional laminates in order to, firstly, better understand the damage mechanisms involved, and, secondly, be able to provide guidance for a strength improvement of these structures. First, an explicit finite element modelling of unidirectional laminates is developed based on the work of F Pascal dealing with impact modeling on helicopter blades. Thus, a new element that can represent the impact response of unidirectional plies is formulated. The behavior of the bundle of fibers is modeled with rod elements stabilized with specific 2D elements. The degradation is managed using damage based on experimental observations. The parameters of the proposed modelling strategy are identified on the basis of experimental tests carried out on T700/M21 and HTA7/913 composites. The results provided by the modeling are then validated by a comparison with experimental low velocity impact results. Finally, in order to improve the laminate strength, low velocity and medium velocity impacts on hybrid unidirectional/woven composite laminates are studied experimentally and with the developed modelling strategy

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3

Vogler, Tracy John. "On the failure and post-failure of fiber composites in compression /". Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

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4

Wu, Xiang. "Thermoforming continuous fiber reinforced thermoplastic composites". Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/9383.

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5

Christen, Jean-Loup. "Acoustic transmission through composite shells with noise treatment : Modelling and sensitivity". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEC028.

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La transmission acoustique de plaques et de coques est un problème présent dans de nombreuses industries, de l'automobile à l'aéronautique en passant par le génie civil. Il s'agit alors, en présence d'une source externe, de limiter le niveau de bruit à l'intérieur d'une cavité enclose par une structure vibrante, qu'il s'agisse d'une voiture, d'un avion ou d'un immeuble.Les matériaux composites sont de plus en plus largement utilisés par toutes les industries du transport, du fait de leur faible masse rapportée à leur grande rigidité. Ces caractéristiques, utiles pour réduire la consommation énergétique des véhicules, sont cependant un handicap lorsqu'il s'agit de limiter le niveau de bruit intérieur. Il est alors nécessaire d'ajouter des protections acoustiques. On s'intéresse dans ce travail à la transmission d'un bruit produit à l'extérieur de la cavité, et à des solutions antibruit passives, utilisant des matériaux poreux absorbants. Ceux-ci, mousses ou laines minérales, présentent en général de bonnes performances acoustiques pour des fréquences élevées, mais nettement mois intéressantes en basses fréquences. Ce travail s'inscrit dans le cadre d'un projet international ayant pour objectif d'étudier la réduction de bruit à travers des structures composites incluant des protections acoustiques passives. Deux axes y sont privilégiés, la modélisation et l'analyse de sensibilité. En effet, les matériaux poreux et composites présentent souvent de grandes incertitudes, dues au procédé de fabrication, à la difficulté de mesure, ou encore simplement à des choix de conception à faire. On cherche donc à s'assurer de la robustesse des solutions étudiées.Cette thèse est organisée en trois parties. La première traite de la modélisation des structures composites et des traitements poroélastiques. On s'intéresse surtout à deux types de structures, les plaques et les cylindres, pouvant dans les deux cas inclure un grand nombre de couches et de matériaux différents. La deuxième partie traite des méthodes d'analyse de sensibilité, et d'applications dans le cas de la transmission acoustique à travers des structures composites. On s'intéressera enfin dans la troisième partie à l'effet du traitement poroélastique, à travers des études numériques et expérimentales
Acoustic transmission through plates and shells is a problem that appear in many applications, for example in the automotive or aerospace industries, or in civil engineering. The idea is to reduce the noise level inside a caivty enclosed by a vibrating structure, which may be a car, a plane or a building. Composite materials are widely used in the transportation industries due to their light weight and high mechanic resistance, but these features tend to increase the acoustic transparency of the structures, thus making it necessary to add acoustic protections for reducing noise in the enclosed cavity. The most frequently used acoustic protections take the form of layers of poroelastic materials, which are very efficient noise absorbers in high frequencies, but perform less efficiently in lower frequency ranges.This thesis is part of an international project aimed at improving the noise reduction performance of composite structures through passive sound packages. This implies the development of reduced models of acoustic transmission through such structures, and optimization studies on these models. Besides, the robustness of a solution with respect to uncertainties in the model have to be ensured. This thesis is organised in three parts, dealing with numerical modelling, sensitivity analysis for acoustic transmission and the effect of a porous treatment on sound transmission

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6

Hsu, Sheng-yuan. "On the prediction of compressive strength and propagation stress of aligned fiber-matrix composites /". Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

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7

Podnos, Eugene Grigorievich. "Application of fictitious domain method to analysis of composite materials /". Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

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8

Ellerby, Donald Thomas. "Processing and mechanical properties of metal-ceramic composites with controlled microstructure formed by reactive metal penetration /". Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/10583.

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9

Cheung, Yin Nee. "Investigation of concrete components with a pseudo-ductile layer /". View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202004%20CHEUNGY.

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10

Palmer, Nathan Reed. "Smart Composites evaluation of embedded sensors in composite materials /". Thesis, Montana State University, 2009. http://etd.lib.montana.edu/etd/2009/palmer/PalmerN0809.pdf.

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As an emerging form of renewable energy, horizontal wind turbines have experienced advancements in improving efficiency and reliability. These advances have pushed the limits of current technology used in wind turbines. Smart blades have been proposed as a method of addressing these limitations. Sensor integration within blade construction is the first step in development of smart blades. Thus, several low cost sensors were chosen, 1 axis strain gages, polyvinylidene fluoride films (PVDF), and single mode fiber optics either coated in acrylate or polyimide. To ensure successful bonding between sensor and composite two surface treatment techniques were developed. The first, dipping of the sensor into a bath of 20% by weight solution of nitric acid and the second was submersion of the sensor in the nitric acid for ten seconds prior to removal. These treatments were compared against sensors not surface treated prior to embedding. These sensors were embedded within samples created of fiberglass and epoxy or vinyl ester resin. Two different material tests were conducted. Tensile testing allowed for evaluation of sensor sensitivity, sensor failure point, material tensile modulus, and material tensile strength. Mode I fracture toughness evaluation, indicated the level of successful bonding which occurred during resin curing. Field Emission Scanning Electron Microscopy (FESEM) was conducted to further confirm the level of bonding between resin and sensor, post fracture. Results for embedded strain gages showed an adverse effect for vinyl ester samples. Epoxy samples fared better, thus concluding manufacturing success for epoxy samples, submersion being preferred, and alternative methods needed for vinyl ester samples. PVDF films had good qualitative FESEM images combined with increasing trends. It was concluded that integration for both resin groups with sensors submerged in nitric acid was successful. Fiber optics coated in acrylate also showed good bonding under FESEM imaging as well as testing. It was thus concluded that submersion was the preferred treatment. Lastly, fiber optics coated in polyimide embedded in vinyl ester composites showed significant drawbacks and it was concluded that alternative methods need exploration. Those embedded in epoxy were successfully integrated and submersion in nitric acid showed the most potential.

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11

Tompson, Carl G. "Radiographic determination of the lay-up influence on fatigue damage development under bearing/bypass conditions". Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29689.

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Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Dr. Steve Johnson; Committee Member: Dr. Andrew Makeev; Committee Member: Kyriaki Kalaitzidou. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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12

Veazie, David R. "Modeling of fiber reinforced composites incorporating distinct interface properties". Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/17385.

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13

Lee, Jaehong. "Vibration, buckling and postbuckling of laminated composites with delaminations". Diss., This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-06062008-170322/.

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14

Ward, William F. "A theoretical investigation into the inelastic behavior of metal-matrix composites". Thesis, Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/17244.

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15

Horden, John. "Composites". Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/394007.

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The four main chapters in this dissertation, while each largely self-standing, can be seen as together providing an extended defence of the view that classical mereology is analytically true. In chapter 1, I criticise Eli Hirsch’s influential deflationary account of the ontological debate on composition, according to which universalists and nihilists talk past each other, and neither speak truly in ordinary language. In chapter 2, I respond to a recent argument from Louis deRosset against the standard assumption that analytic truths are somehow metaphysically insubstantial. In chapter 3, I criticise various attempts to reconcile mereological nihilism with the truth of everyday discourse. Finally, in chapter 4, I argue for the analyticity of classical mereology, and answer the main objections to this view of composition.
Si bien los cuatro capítulos principales de esta tesis pueden leerse de forma independiente, se pueden considerar conjuntamente como una defensa extensa y detallada de la posición según la cual los axiomes de la mereología clásica son verdades analíticas. En el primer capítulo, critico la teoría deflacionista de Eli Hirsch, que afirma que los universalistas y los nihilistas no se entienden, y que ambas teorías son falsas en el lenguaje ordinario. En el segundo capítulo, rebato un argumento reciente de Louis deRosset en contra de la asunción estándar según la cual las verdades analíticas son, de alguna forma, metafísicamente insustanciales. En el tercer capítulo, critico varios intentos de reconciliar el nihilismo mereológico con la verdad del discurso cotidiano. Finalmente, en el cuarto capítulo, argumento en favor de la analiticidad de la mereología clásica, y respondo a las objecciones principales contra esta teoría de la composición.

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16

Perkins, Holly Lyn. "Air knife fiber spreading in composites manufacturing". Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/19068.

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17

Somanath, Nagendra. "A finite element cure model and cure cycle optimization for composite structures". Thesis, This resource online, 1987. http://scholar.lib.vt.edu/theses/available/etd-04272010-020304/.

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18

Call, Russell Kent. "Parameter establishment and verification of a fabrication stress model and a thermo-kinetic cure model for filament wound structures". Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-08142009-040256/.

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19

Chang, Sheau-Miin. "Critical evaluation of strong organic fibers vis-a-vis mechanical performance in flexible structures". Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/8479.

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20

Kokan, David R. "Development and use of an improved filament-winding process model". Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/12261.

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21

Yang, Heechun. "Modeling the processing science of thermoplastic composite tow prepreg materials". Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/17217.

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22

Kothidar, Arjun. "Use of finite element method to evaluate the strength response of notched composite laminates under tension". Pullman, Wash. : Washington State University, 2008. http://www.dissertations.wsu.edu/Thesis/Fall2008/A_Kothidar_120508.pdf.

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Abstract (sommario):

Thesis (M.S. in mechanical engineering)--Washington State University, December 2008.
Title from PDF title page (viewed on July 6, 2009). "Department of Mechanical and Materials Engineering." Includes bibliographical references (p. 115-118).

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23

Pascal, Serge. "Comportement mécanique de composites mortier-polymère". Châtenay-Malabry, Ecole centrale de Paris, 2002. http://www.theses.fr/2002ECAP0851.

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L'objectif de ce travail était d'apporter une meilleure compréhension de l'influence des latex sur les propriétés mécaniques des mortiers. Par ailleurs, nous avons modélisé leur comportement afin de réaliser des simulations numériques d'un "essai-métier". Pour cela, nous avons tout d'abord élaboré des composites mortier-styrène butadiène avec un rapport massique polymère sur ciment variant de 0 à 15 %, tout en contrôlant l'effet entraîneur d'air du latex et l'hydratation du ciment. Nous souhaitons obtenir des matériaux présentant peu de différences vis-à-vis de ces deux paramètres. Nous avons ensuite réalisé des analyses sur les pâtes à l'état frais (air occlus, temps de prise, conductivité électrique) comme à l'état durci (DRX, spectroscopie infrarouge, porosimétrie au mercure) afin de vérifier si leurs phases minérales étaient effectivement de même nature. Nous avons également étudié la façon dont les phases polymère et minérale étaient agencées. La caractérisation mécanique des matériaux a été réalisée à partir d'essais de compression uniaxiale et de flexion trois points. Nous avons montré en particulier que la percolation de la phase polymère en un réseau continu améliore la résistance mécanique des composites en flexion trois points. Le comportement endommageable des composites est décrit à l'aide d'un modèle développé par Dragon (A. ) et Halm (D. ). Ce modèle s'est avéré pertinent pour décrire le comportement mécanique de nos matériaux. Finalement, il a été appliqué avec succès à la simulation d'un "essai-métier". Ce travail offre une meilleure compréhension de l'influence des latex sur les propriétés mécaniques des composites mortie-polymère. De plus, les nombreuses analyses microstructurales réalisées apportent des résultats complémentaires sur l'influence de ces additifs sur : l'hydratation du ciment, la porosité, et l'agencement du polymère au sein de la phase minérale.

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24

Wang, Xufeng Materials Science &amp Engineering Faculty of Science UNSW. "Application of single-part adhesives as healing agent in self-healing composites". Awarded by:University of New South Wales. Materials Science and Engineering, 2007. http://handle.unsw.edu.au/1959.4/32233.

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The aim of this study was to develop a new single-part healing system for self-healing composites. The self-healing approach to composite repair has been developed in the last two decades and means that a damaged area can be repaired by material already housed within the structure. The background and development of self-healing has been reviewed. The two main self-healing mechanisms are discussed. To date only two part self healing systems have been examined. These require diffusion of the separate constituents to a single location in order to effect cure and restore strength. Single part adhesives do not have this disadvantage and are therefore very attractive. Several candidate single-part adhesive or resin systems were considered and discussed according to the critical requirements of a self-healing system. A series of experiments was undertaken to evaluate the possibility of candidate adhesive systems being effective for self-healing by focusing on the determination of storage stability and bonding efficiency. The results of storage stability testing showed that the stability of cyanoacrylate and polyurethane adhesives was poor. However silane and polystyrene cements showed good storage stability. Very low bonding efficiency was achieved with polystyrene cement but a 22% strength recovery was obtained with the silane 3-[tris(trimethylsiloxy)silyl]-propylamine. Suggestions for further research into single-part healing systems are also given.

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25

Scott, David William. "Short- and long-term behavior of axially compressed slender doubly symmetric fiber-reinforced polymeric composite members". Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/19276.

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26

Proia, Emiliano. "Modélisation de treillis composites commandables". Paris 6, 2004. http://www.theses.fr/2004PA066572.

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27

Norpoth, Lawrence R. "Processing parameters for the consolidation of thermoplastic composites". Thesis, Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/19099.

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28

Graham, Samuel Jr. "Effective thermal condutivity of damaged composites". Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/16935.

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29

Zhang, Fangzhou. "Multiscale modeling of laminated composites under extreme environmental conditions". Thesis, Cachan, Ecole normale supérieure, 2014. http://www.theses.fr/2014DENS0027/document.

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À haute température, l'oxygène réagit avec la matrice organique du matériau composite, ce qui change les propriétés du matériau et réduit la résistance à la rupture globale. Mais la compréhension de la dégradation du composite stratifié oxydé, en particulier son comportement à l'échelle du pli, est aujourd'hui limitée et phénoménologique. Les travaux dans cette thèse ont été réalisés pour donner notre contribution sur les aspects méthodologiques de ce sujet. Des essais sont réalisés pour caractériser expérimentalement le comportement d'éprouvette oxydée : en particulier, un nouveau essai, l'essai 'oxy-délaminage', a été développé pour identifier la ténacité du matériau composite vieilli. Une stratégie a été proposée d'étudier le problème à partir des propriétés de la matrice oxydée à l'échelle fibre/matrice et jusqu'à la reproduction et la prédiction du comportement de fissuration transversale des échantillons oxydés à échelle méso via un procédé d'homogénéisation
At high temperature, the oxygen reacts with the organic matrix of composite material, which changes the material properties and reduces the resistance to global failure. But understanding on the degradation of the oxidized composite laminate, particularly its damage behavior, is now limited and phenomenological. Work in this thesis has been made to give our contribution to the methodological aspects of this topic. Tests are performed to characterize experimentally the behaviors of the oxidized specimens: in particular, a new test test oxy-delamination ', was developed to identify the tenacity of composite material aged. A strategy has been proposed to study the problem from the properties the oxidized matrix at the fiber/matrix scale up to the reproduction and predicting the behavior of transverse cracking of the sample at the scale of a ply via a homogenization process

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30

James, Aaron. "Development of composites materials from waste paper and plastic". Australian Digital Thesis Program, 2006. http://adt.lib.swin.edu.au/public/adt-VSWT20070130.165426/index.html.

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Thesis (PhD) - Swinburne University of Technology, Industrial Research Institute Swinburne - 2006.
A thesis submitted for the degree of Doctor of Philosophy, Industrial Research Institute Swinburne, Swinburne University of Technology - 2006. Typescript. "August 2006". Includes bibliographical references (p. 361-389).

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31

Allen, Abraham Keith. "A method for winding advanced composites of unconventional shapes using continuous and aligned fibers /". Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd639.pdf.

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32

Han, Jie. "An experimental and analytical study of the behavior of fiber-reinforced polymer piles and pile-sand interactions". Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/20296.

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Peterson, Nels Royal. "Wood-thermoplastic composites manufactured using beetle-killed spruce from Alaska's Kenai Peninsula". Online access for everyone, 2008. http://www.dissertations.wsu.edu/Thesis/Summer2008/N_Peterson_060508.pdf.

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Anegunta, Swetha. "Manufacture and rehabilitation of guard-rail posts using composites for superior performance". Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1419.

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Thesis (M.S.)--West Virginia University, 2000.
Title from document title page. Document formatted into pages; contains xvii, 153 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 120-123).

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Farooq, Mohammed. "Development of FRP based composite fibre for fibre reinforced cementitious composites". Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/57668.

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This thesis describes a method of development of a novel fibre based on fibre reinforced polymers (FRP), for use fibre reinforcement in concrete. Thermosetting epoxy resin matrix were reinforced with E-glass, S-glass, and Carbon fibre to produce different types of composite fibres. The FRP panels were produced using the Vacuum Infusion technique, and then cut to different fibre sizes. The volume fractions of reinforcements within the FRP fibre were controlled by using woven and unidirectional fabrics. The number of layers of reinforcing fibres were also changed, to obtain the optimal thickness of the fibres. The FRP material was characterized by means of tensile tests and microscope image analysis. Four different compositions of FRP were produced with tensile strengths ranging from 195 MPa to 950 MPa. The different combinations in geometry broadened the total number of fibres investigated to 12. Single fibre pullout tests were performed to obtain the fundamental fibre-matrix interfacial bond parameters for the different FRP fibres. The FRP fibres, being hydrophilic, along with having a unique rough surface texture, showed a good bond with cement matrix. A bond strength superior to industrially available straight steel fibres and crimped polypropylene fibres has been observed. The 3 best fibres were then chosen to examine the flexural behaviour FRP fibre reinforced concrete beams. The optimized FRP fibres, one each of Glass FRP and Carbon FRP were then further investigated to study the effect of matrix maturity, temperature, fibre inclination, and loading rate on the fibre-matrix interfacial behaviour using single fibre pullout tests. Scanning Electron Microscope (SEM) analysis was carried out to identify the effect of above-mentioned factors on the surface characteristics of the fibre. An attempt was also made to optimize the fibre-matrix interface to achieve an optimized failure mechanism by coating the fibre with oil. The ability of the fibre to transfer stresses across a cracked section over extended periods has been investigated by means of fibre-relaxation tests. Finally, to assess durability, the fibres were conditioned at high pH and high temperature after which single fibre pullout, direct tension tests, & SEM analysis were conducted.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

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36

El-Ashkar, Nabil H. "Wood pulp microfibers in cement-based composites : improving fiber distribution and characterizing composite behavior". Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/21518.

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García, Ramírez José Ernesto. "Consumption composites". Thesis, Konstfack, Inredningsarkitektur & Möbeldesign, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:konstfack:diva-3009.

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Consumption composites is a project in which I want to reflect about the concept of recycling, to explore the idea of a society result of recycling, to see if it could be helpful to think in it in another way. I explore the act of recycling as a statement, as a discourse not as a solution for industrial production waste, the relation between the semiotics of the discarded material and the recycled resulting piece but most the interaction between these two and the final user/ spectator[1]. By looking at the soprum[2] is possible to see estrange combinations for instance baby pap packages with liquor bottles, political propaganda together with brochures advertising winter sports, a table with beer cans and a painting it. It is a composition in itself is a sort of collage where all possible come together. I found inspiring how waste could be classified from one criterion but mixed in other criteria like the cultural and semiotic one. Although there are differences between neighborhoods and municipalities, the half-ton of garbage produced by a Swedish citizen per year is classified by if the material could be recycled, composted, burn, landfilled or if it is hazardous for the environment or humans[3]. I put the waste together in order to create structures that further on could be used to build either furniture or spaces. I worked only with materials that were classified in the same category for instance newspapers or uncolored glass, keeping as much as possible the original form of the existing material in order to be able to see their original meaning or purpose. I noticed that the material transform to something new while keeping some of their form and semiotic properties when it is covered with a sort of layer. Something that reminds me the landfill, where the material is buried and then it is a new beginning but there is some transformation in the landscape that never would be the same. This is more an intervention in the materials in their way to their following step either landfill, recycling, burn or compost. The form and statement is the result of consumption from Stockholm where the material was collected and my own aesthetic intentions. [1](Debord, 1994) [2]Soprum: Swedish word for “garbage room” there are several versions of it but it is basically a room where the garbage can be sorted in different bins. [3]Avfall Sverige – Swedish Waste Management, was founded in 1947. It is a stakeholder and trade association in the field of waste management and recycling.

The full version contain an image is only for the archive because it contain a picture without copyright

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38

Harfouche, Nesrine. "Electrodéposition de revêtements composites à base de polyaniline pour des applications de batterie Lithium-ion et de protection contre la corrosion". Thesis, Toulon, 2016. http://www.theses.fr/2016TOUL0013/document.

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Dans cette étude, nous avons préparé deux matériaux composites conducteurs par le procédé d’électropolymérisation. Lebut de la première partie de la thèse était l’élaboration de films composites polyaniline /LiMn2O4 pour leur applicationcomme matériau de cathode dans les batteries lithium-ion. Les analyses par diffraction des rayons X, analyse EDX etspectrométrie IRTF ont confirmé l'incorporation de LiMn2O4 dans les films composites. Les analyses électrochimiquesdes films obtenus ont mis en évidence une conductivité plus élevée des films composites comparée à la conductivité desfilms de PANI. La deuxième partie a été consacrée à la préparation de l’oxyde de graphène (OG) à partir de graphiteselon 2 méthodes de synthèse dérivées de la méthode de Hummers. Les résultats obtenus ont montré que le de gréd’oxydation des feuillets n’était pas le seul critère à prendre en compte pour évaluer la stabilité du OG dans l’eau. Lesfeuillets d’OG obtenus ont été incorporés à la polyaniline par électropolymérisation d’une suspension d’OG et d’anilineen milieu neutre. Le milieu électrolytique neutre conduit à des chaînes oligomères de PANI de faible masse molaire avecune proportion significative d’unités aromatiques mono et 1,2-disubstituées dans la structure finale. Différents substratsmétalliques ont été testés et les films ont été en particulier déposés sur fer afin d’évaluer leur protection anticorrosion
In this study, we prepared two conductive composite materials based on polyaniline (PANI) byelectrodeposition. First, we investigated the development of new polyaniline/LiMn2O4 composite films forapplication as cathode material in lithium-ion batteries. Analysis by X-ray diffraction, EDS analysis and FTIRspectroscopy confirmed the incorporation of LiMn2O4 in composite films. The electrochemical analysis of thefilms obtained showed a higher conductivity of the composite films compared to the conductivity of the filmsof PANI. The second part was devoted to the preparation of oxidized graphene (GO) from graphite by 2methods of synthesis derived from the method of Hummers. The results showed that the degree of oxidation ofthe graphene sheets was not the only criterion in assessing the stability of GO in water. Electropolymerizationof aniline in a neutral electrolyte containing GO sheets was carried out to prepare PANI-GO composite films.The neutral electrolytic medium leads to PANI oligomer chains of low molecular weight with a significantproportion of aromatic mono units and 1,2-di-substituted units in the final structure. The electrodeposition wasperformed on inert and oxidizable metals. The corrosion protection efficiency of PANI/GO composite filmswas studied in HCl corrosion medium

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39

Sacks, Serena. "Effects of thermal aging on the mechanical behavior of K3B matrix material and its relationship to composite behavior". Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/18865.

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40

Breunig, Thomas M. "Nondestructive evaluation of damage in SiC/Al metal matrix composite using x-ray tomographic microscopy". Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/19999.

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41

Klug, Jeremy Hager. "High-performance adhesive systems for polymer composite bonding applications /". Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/9883.

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42

Na, Gwang-Seok. "Load-displacement behavior of frame structures composed of fiber reinforced polymeric composite materials". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26699.

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Thesis (Ph.D)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Dr. Leroy Z. Emkin; Committee Co-Chair: Dr. Abdul-Hamid Zureick; Committee Member: Dr. Dewey H. Hodges; Committee Member: Dr. Kenneth M. Will; Committee Member: Dr. Rami M. Haj-ali. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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43

Montagne, Benoit. "Effet de l'interaction fixation composite sur les modes de rupture des assemblages boulonnées composites". Thesis, Toulouse, ISAE, 2020. http://www.theses.fr/2020ESAE0012.

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La problématique abordée dans ces travaux de thèse est l’influence de l’interaction entre lesfixations et le composite sur la tenue des assemblages boulonnés composites. Le passage desefforts d’assemblages dans le composite par les boulons engendre des dégradations localesconduisant à des modes de rupture variés du composite en fonction des principaux paramètresde conception. L’objectif de cette thèse est d’identifier la complexité de modélisation nécessairepour traduire l’effet de ces paramètres de conception sur l’apparition des différents modes derupture des matériaux composites et leur conséquence sur le dimensionnement desassemblages boulonnés. Cette thèse repose sur l’étude d’une importante base de donnéesexpérimentale de résultats d’essais sur assemblages en simple et double cisaillement fournieDassault Aviation à laquelle s’ajoute des essais multi-instrumentés menés au laboratoire. Cetteétude permet d’une part d’identifier les paramètres les plus influents sur les modes de rupturedes assemblages boulonnés composite et d’autre part d’identifier les dégradations entrainant lesmodes de ruptures observées. Ces résultats expérimentaux servent également de base decomparaison pour la validation des modèles éléments finis développés. Ces modèles sont mis aupoint dans un souci de complexité croissante. Cette complexité se décompose en un aspectgéométrique, c’est-à-dire l’étude de la modélisation des différentes pièces en jeu, et en un aspectmatériel avec l’étude du comportement matériau de ces pièces. L’analyse des modèles élémentsfinis linéaires basés sur des cinématiques de membrane et des plaques révèle la limite del’utilisation de critères de rupture au premier pli pour les assemblages boulonnés. Cesmodélisations sont alors enrichies avec une loi de comportement endommageable du composited’une part. Cela permet de mettre en place des scénarios d’endommagement du matériau et deréaliser des corrélations essais/calculs. D’autre part, un modèle volumique est développé pourévaluer l’apport de cette modélisation avec notamment une meilleure représentation desinteractions entre les substrats
The problematic studied in this thesis is the influence of the interaction between fixations andcomposite on the bolted joint behavior. Stresses are crossing the joint thanks to the bolt. Thiscreates local degradations and results in various failing modes depending on conceptionparameters. The goal of this thesis is to identify the needed complexity to explain the effect ofthese conception parameters on the various composite failing modes apparition and theirconsequences on bolted joints dimensioning. This study is based on the analysis of an importantexperimental database on composite single and double lap bolted joints provided by the industrialpartner and on multi-instrumented tests lead in the laboratory. It permits identifying the mostinfluent parameters on the failure modes of composite bolted joints. Moreover the degradations ofthe composite material are studied in order to establish damaging scenarios. These experimentalresults are compared to finite element models to validate their robustness. These finite elementmodels are developed with a growing complexity. This complexity is decomposed in two aspects:the geometrical modeling of the different parts and the material behavior. The analysis of linearfinite element model based on membrane and shell cinematic underlines the limit of using failurecriteria to study the failure of composite bolted joints. Thus these models are enhanced with thenonlinear behavior of the composite material thanks to a continuous damaging law. It permitsestablishing damaging scenarios and to compare them with experimental results. Finally avolume model is developed to ensure a better representation of the parts interaction and evaluatethis contribution on the study

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44

Alvarez-Valencia, Daniel. "Structural Performance of Wood Plastic Composite Sheet Piling". Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/AlvarezValenciaD2009.pdf.

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45

Urbanetto, Peres Bernardo. "Experimental dental composites with electrospun nanofibers and nanofibrous composites". Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58069.

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Electrospun nanofibers with and without nanoparticles are poorly explored in dental research. Nanocrystalline cellulose is a nanoparticle with distinguished properties that has already been associated with nanofibers, but yet not applied to any dental aspect. The objective of this work was to investigate the use of polyacrylonitrile (PAN) nanofibers containing nanocrystalline cellulose (NCC) in the light of the mechanical behavior of fibrous mat and experimental dental composites. Three experiments were performed to answer the following research questions: 1) Can nanocrystalline cellulose improve mechanical properties of polyacrylonitrile nanofiber meshes? 2) Does the method of dispersion (simple mixture vs. with solvent exchange) of NCC in PAN solution affect fiber formation and the respective properties of the meshes? and 3) Can NCC-containing PAN electrospun nanofibers affect flexural properties of experimental dental composites? Results showed that nanocrystalline cellulose, at low concentrations, significantly increases PAN nanofibers tensile properties (chapter 2). Dispersion methods affected both the morphology and mechanical properties of the fibers (chapter 3). Finally, when NCC-containing PAN nanofibers were used to produce experimental dental composites, there was a significant improvement in flexural strength and work of fracture (chapter 4). In conclusion, the findings indicated that the use of electrospun nanofibers and nanofibres containing nanoparticles is a promising approach to reinforce dental composites.
Dentistry, Faculty of
Graduate

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46

Xu, Jian. "Rehabilitation of concrete highway bridge members using fiber-reinforced composites". Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/20180.

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47

Vautey, Philippe. "Bilan des performances mécaniques des composites carbone/thermoplastiques pour l'aéronautique". Compiègne, 1993. http://www.theses.fr/1993COMP0639.

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Ce travail a été orienté pour dresser un bilan des performances mécaniques des composites à matrice thermoplastique, en s'efforçant d'identifier les sollicitations élémentaires sur lesquelles sont basées les sélections matériaux, pour un concepteur de structures aéronautiques. Le composite thermoplastique APC2/AS4 de la société ICI a servi de support à cette étude. Au delà d'une comparaison thermoplastique/thermodurcissable, l'influence d'une matrice ductile sur les propriétés des stratifiés a pu être étudiée grâce à l'APC2, qui se démarque nettement des systèmes thermodurcissables plus fragiles utilisés en production à ce jour. Après que le comportement élasto-plastique marque de la matrice Peek au sein du composite ait été souligné, l'analyse des modes de ruines a permis de préciser les raisons du compromis mécanique réalisé sur stratifiés APC2 vis à vis de la traction, de la compression, et de la sensibilité aux dommages d'impact et à l'environnement. Parallèlement, des aspects spécifiques à la morphologie semi-cristalline de ce thermoplastique ont été étudiés. Des conditions limites de moulage ont été proposées pour éviter certains risques de fragilisation.

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48

Morin, Victor. "Elaboration de composites multiférroïque et caractérisation de l'effet magnétoélectrique". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLN030/document.

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L'effet magnétoélectrique (ME) est la modification de la polarisation électrique par l'application d'un champ magnétique (effet ME direct), ou bien la modification de l'aimantation magnétique par l'action d'un champ électrique (effet ME inverse).L'utilisation de matériaux composites permet de reproduire de manière extrinsèque cet effet. Le couplage mécanique entre des matériaux magnétostrictifs et piézoélectriques fournit un effet ME extrinsèque plus important à température ambiante que celui fournit intrinsèquement. Nous avons dégagé (théoriquement et expérimentalement) différentes caractéristiques de matériaux nécessaires à l'obtention d'un effet ME important et justifé l'utilisation de ferrite et de PZT dans les composites ME. Nous expliquons dans cette thèse, les méthodes de fabrications des différentes géométries de composites étudiées (empilement de couches ou bien inclusions d'une phase dans l'autre). En particulier, l'utilisation du frittage non conventionnel par Spark Plasma Sintering, pour améliorer le couplage mécanique y est abordée. En nous focalisant sur la géométrie en multicouche, nous avons montré l'importance de facteurs tels que le champ démagnétisant ou encore la symétrie de la structure. Nous présentons un prototype de capteur de courant utilisable en génie électrique. Nous en avons montré sa bonne linéarité et sensibilité, mais aussi ses défauts en terme de bande passante
The magnetoelctric (ME) response consists in the modification of the electric polarization by an applied magnetic field (direct effect) or the modification of the magnetic polarization by an applied electric field (inverse effect). Intrinsic multiferroics are rather uncommon and the effect is often weak at room temperature. An alternative route to achieve ME effect, consists in using magnetostrictive and piezoelectric materials and coupling the two phases by mechanical stress. We draw (theoretically and experimentally) some material characteristics to achieve an importantME effect, which justify the use of ferrite and PZT. We describe the production process of the two studied connectivity schemes (stack of layers or inclusion of a phase in another). We focus on the sintering by Spark Plasma Sintering as a potential improvement of the mecanical bonding. We devoted a part of our work on multilayer composite and showed the importance of some factors such as the demagnetizing effect or the symmetry of the structure. We introduce a current sensor prototype suitable for electrical engineering application. We showed its good linearity and sensitivity but also some effects of its bandwidth

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49

Raimondi, Luca <1980&gt. "Theoretical and experimental study of novel hybrid composite and metal-composites interfaces". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/10366/1/Tesi%20dottorato%20Luca%20Raimondi_rev1.pdf.

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The growing demand for lightweight solutions in every field of engineering is driving the industry to seek new technological solutions to exploit the full potential of different materials. The combination of dissimilar materials with distinct property ranges embodies a transparent allocation of component functions while allowing an optimal mix of their characteristics. From both technological and design perspectives, the interaction between dissimilar materials can lead to severe defects that compromise a multi-material hybrid component's performance and its structural integrity. This thesis aims to develop methodologies for designing, manufacturing, and monitoring of hybrid metal-composite joints and hybrid composite components. In Chapter 1, a methodology for designing and manufacturing hybrid aluminum/composite co-cured tubes is assessed. In Chapter 2, a full-field methodology for fiber misalignment detection and stiffness prediction for hybrid, long fiber reinforced composite systems is shown and demonstrated. Chapter 3 reports the development of a novel technology for joining short fiber systems and metals in a one-step co-curing process using lattice structures. Chapter 4 is dedicated to a novel analytical framework for the design optimization of two lattice architectures.
La crescente domanda di soluzioni alleggerite in ogni campo dell'ingegneria, sta spingendo l'industria a cercare nuove soluzioni tecnologiche per sfruttare il pieno potenziale dei diversi materiali. La combinazione di materiali diversi con gamme di proprietà specifiche racchiude in sé una trasparente ripartizione delle funzioni fra componenti, consentendo al contempo un connubio ottimale delle loro caratteristiche. Sia dal punto di vista della progettazione che del processo, l'interazione tra materiali differenti può portare a gravi difetti che compromettono le prestazioni di un componente, anche nell’integrità strutturale. Questa tesi mira a sviluppare metodologie per la produzione, la progettazione ed il controllo di componenti ibridi metallo-composito e compositi ibridi. Nel Capitolo 1, viene esposta una metodologia per la progettazione e la produzione di tubi ibridi in alluminio/composito co-curati. Nel Capitolo 2, viene mostrata e dimostrata una metodologia full-field per il rilevamento del disallineamento delle fibre e la previsione della rigidezza per sistemi fibrorinforzati a fibra lunga. Il capitolo 3 riporta lo sviluppo di una nuova tecnologia per l'unione compositi a fibra corta e metallo in processo di co-curing, utilizzando lattice structures. Il capitolo 4 è dedicato a un nuovo quadro analitico per l'ottimizzazione del design di due tipologie di lattice structure.

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50

Wright, Richard J. "Bolt bearing creep behavior of highly loaded polymer matrix composites at elevated temperatures". Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/17362.

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Tesi sul tema "Composites"

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