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Dissertations / Theses on the topic 'Particulate composite'
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1
Wang, Huaijun. "Creating Virtual Wood Particulate Composites." Fogler Library, University of Maine, 2000. http://www.library.umaine.edu/theses/pdf/Wang.pdf.
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Butsch, Susan Laurel. "Mechanical and physical properties of particulate reinforced composites." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-10312009-020333/.
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Sharifi-Yazdi, Farnaz. "Bioresorbable particulate filled composite for bone regeneration." Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248041.
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Mucharreira, de Azeredo Lopes Sofia. "Statistical analysis of particle distributions in composite materials." Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341906.
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Chalivendra, Vijaya Bhaskar. "Static and dynamic constitutive behavior and fracture of particulate composites /." View online ; access limited to URI, 2003. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3112114.
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Sidbury, Carmen Kay. "Effect of processing conditions on cast particulate reinforced composite materials." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/17607.
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Lemieux, Stéphane. "Thermal expansion study of particulate reinforced aluminum matrix composite materials." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20505.
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The thermal expansion behavior of Duralcan particle reinforced composite materials was investigated. Initially, the temperature dependence of the CTE of Al-Si alloy containing SiC reinforcement particles ranging from 10 to 40% in volume was experimentally examined and compared with standard theoretical model predictions. In addition, the effects of reinforcement volume fraction and nature of the composite constituents during thermal cycling between 25 and 350ºC were determined for Al-Si alloy containing between 10 and 40% SiC particles and Al alloy having 40% alumina in volume. Accurate experimental CTE measurements were made using a high precision Thermomechanical Analyzer system. Silicon carbide reinforced composite average CTE values were bounded by two elastic CTE theoretical models consisting of Schapery and Kerner predictions over the 25--350ºC interval for reinforcement volume fractions between 10 and 40%. The CTE mismatch between the particles and the matrix does not appear to be the only factor influencing the expansion response of the composites. Indeed, the nature of the composite constituents also plays an important role by influencing the ductility and bonding of the particle-matrix interface.
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Lemieux, Stephane. "Thermal expansion study of particulate reinforced aluminum matrix composite materials." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0005/MQ44021.pdf.
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Wahlers, John Colin. "A study of the extrusion of particulate cellulosic composite materials." Thesis, Brunel University, 1988. http://bura.brunel.ac.uk/handle/2438/7868.
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Traditional routes to the manufacture of timber based composite materials such as particleboard rely on platen pressing a premix of carefully chosen and prepared timber particles and an adhesive to produce flat sheets. Historically such routes have made very inefficient use of forest resources, and because of the planar nature of the composite produced, the finished articles have enjoyed a reputation of being of poor quality and "cheap". The work documented in this thesis sought to examine alternatives to the traditional manufacturing methods in terms of both raw materials and processing route, and to establish technical, economic, and environmental boundaries for the use of the alternatives. Having settled upon extrusion as the most likely technique with which to proceed, the investigation was carried forward by the construction of a series of experimental instruments with the joint aims of refining the technique to a realistic working level and investigating the underlying mechanical principles behind the process. Recourse to the literature of polymer rheology, fluid mechanics, and soil mechanics gave the basis for a crude mechanism hypothesis, and iterative improvements in the instrumental techniques yielded data with which this could be refined. Although some correlation between the extrusion behaviour of this system with other more easily quantifiable systems was found, there is still considerable work required in defining the dynamic changes in the material properties as the raw material is extruded. Small scale production experiments proved successful, however, and an elementary financial model of a suitable production facility indicated that the techniques developed could be used as the basis of an environmentally acceptable, economically viable, low technology industry.
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Lanz, Herrera Ruben Waldemar. "Machinability of a particulate-filled polymer composite material for rapid tooling." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/16727.
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Herba, Edward. "Constitutive analysis and extrusion modeling of 6061 alloy and particulate composite." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0001/MQ44805.pdf.
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Styles, Clinton Mark. "Fracture and fatigue behaviour of a particulate reinforced aluminium based composite." Thesis, University of Southampton, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239454.
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Gavroňová, Ivana. "Příprava a charakterizace vysoce plněných kompozitních systémů pro stomatologické aplikace." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-295702.
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Master thesis deals with highly filled particulate composite materials for dental applications. In the practical part, the dimetacrylate matrix was filled with a mixture of particles of different types and different sizes to achieve the maximum possible packing. Moreover, filler content and the influence of filler on composite material was studied. Hydrolytic stability was also tested on composite materials. The methods used to characterize composite materials were bending test, thermogravimetric analysis (TGA), differential scanning photocalorimetry (DPC), dynamic-mechanical analysis (DMA) and scanning electron microscopy (SEM). Curing of the matrix was characterized by the degree of conversion, the heat of polymerization and the polymerization rate. Furthermore the polymerization shrinkage was measured. The glass transition temperature, the dynamic modulus at 40 °C and 100 °C, the modulus of elasticity, the strength, the critical value of the stress factor and the critical energy release rate were found in the tested samples.
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Yilmaz, Hamdi Sencer. "Characterization Of Silicon Carbide Particulate Reinforced Squeeze Cast Aluminum 7075 Matrix Composite." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/12605261/index.pdf.
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The aim of this study is to investigate the mechanical behavior and its relation with processing and microstructure of the silicon carbide particulate (SiCp) reinforced aluminum matrix composite. Aluminum 7075 alloy is chosen as matrix alloy, in which zinc is the main alloying element. Four different additions of SiCp were used and the weight fractions were 10%, 15%, 20% and 30%. Composites were processed by with squeeze casting and the applied pressure during casting was 80 MPa. The mould is specially designed to produce both specimens ready for tensile and three point bending tests.
Both as-cast and heat treated aluminum composites were examined and T6 heat treatment was applied. Three point bending tests were performed to reveal the fracture strength of aluminum composites. 10wt% SiCp aluminum composites showed the maximum flexural strength in both as-cast and heat treated composites. The mechanical test results revealed that precipitated phases in heat treated composites, behaved like fine silicon carbide particulates and they acted as barriers to dislocation motion. Maximum flexural strength increased about 40 MPa (10%) in as-cast and 180 MPa (44%) in heat treated composites. Tensile testing was also conducted to verify the results of the three point bending tests.
Hardness tests were done to find the effect of silicon carbide addition and to find the peak hardness in heat treatment. For as-cast specimens hardness values increased from 133 to 188 Vickers hardness (10 kg.) with increase in SiCp content from 0 to 30wt% and for heat treatment specimens hardness values increased from 171 to 221 Vickers hardness (10 kg.). The peak hardness values were obtained at 24 hours precipitation heat treatment. SEM studies were carried out to examine the heat treated composites, to take SEM photographs and to obtain a general elemental analysis. Theoretical volume percentage addition of SiCp was checked with Clemex Image Analyzer program. Distribution of SiCp was determined by mettalographic examination. Second phases that were formed during heat treatment was searched by x-ray analysis.
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Goteti, Vasudha. "Parametric modeling of bolted joints between components made of particulate composite materials." Morgantown, W. Va. : [West Virginia University Libraries], 2003. http://etd.wvu.edu/templates/showETD.cfm?recnum=3003.
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Thesis (M.S.)--West Virginia University, 2003.Title from document title page. Document formatted into pages; contains xii, 79 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 78-79).
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Rezvani, Mohamad A. "A study of near tip phenomena for cracks in a particulate composite." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54272.
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An experimental investigation using grids with a frequency of 125 lines/in. (5 lines/mm) was performed on inert propellant and pure binder at two different global head rates of 0.1 in./min (2.5 mm/min) and 1.0 in./min (25.4 mm/min). From the extracted data, displacements, strains, and dominant eigenvalue for displacement were calculated. An idealized model was used to explain the high strain zone ahead of inert propellant that caused severe blunting at the crack tip.
Using the available algorithms and three dimensional photoelasticity, the dominant stress singularity order values were calculated in a four point single edged cracked bend specimen with both straight front and thumbnailed cracks. The free surface values are the same as for the inert propellant and in good agreement with analytical values.
A boundary layer is observed in the singularity order which extends towards the mid-plane of the specimen. This region is about twenty percent of the distance from the free surface to mid-depth of the fractured body.
The slow and fast head rates alter the global behavior of the specimen as well as the density of the displacement and strain contours. However, the near tip mechanisms are not altered.Ph. D.
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Owens, Anthony Taylor Tippur Hareesh V. "Development of a split Hopkinson tension bar for testing stress-strain response of particulate composites under high rates of loading." Auburn, Ala., 2007. http://repo.lib.auburn.edu/Send%2002-04-08/OWENS_ANTHONY_54.pdf.
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Wong, Franklin C. "Analysis and prediction of particulate composite mechanical behavior using a nonlinear micromechanical theory." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25471.pdf.
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Shyong, Jian-Hua. "The relationship between microstructure and mechanical properties of particulate reinforced metal matrix composite." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358735.
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Stevanovic, Dejan, and dejan@mso anu edu au. "Delamination Properties of a Vinyl-Ester/Glass Fibre Composite Toughened by Particulate-Modified Interlayers." The Australian National University. Faculty of Engineering and Information Technology, 2002. http://thesis.anu.edu.au./public/adt-ANU20030421.212730.
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The main aim of this work is to examine fracture toughness improvement mechanisms of a
composite material containing tough interlayers modified with large thermoplastic
particles.
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Various vinyl-ester (VE)/ poly(acrylonitrile-butadiene-styrene) (ABS) blends were used
for the interlayer-toughening of a VE/glass fibre composite to increase delamination
resistance of the material under mode I and mode II loading. Dry ABS powder was mixed
with the liquid resin in four different weight ratios: 3.5, 7, 11 and 15 phr (parts per
hundred parts of resin) while the layer thickness was varied from 150 to 500um.
Firstly, the tensile and mode I fracture toughness properties of the VE/ABS blends were
assessed, and, by using the Raman Spectroscopy technique, a chemical reaction was
discovered which occurred during ABS/VE mixing. This reaction consisted of butadiene
dissolution from the ABS particles into the VE. Also, butadiene saturation within the VE
was achieved at a composition of around 7% ABS particle content. Both mode I and mode II
fracture toughness of the composite were significantly improved with the application of
interlayers. Mode I fracture toughness GIc was found to be a function of
interlayer thickness and ABS particle content variations, with the latter dominating
GIc after the saturation point. Mode II fracture toughness was found to be
independent of interlayer thickness and only moderately influenced by particle content.
The toughening mechanisms that were the most influential within this interlayered
material were plastic deformation and micro-cracking of the layer materials. Evidence of
both mechanisms was found using optical and scanning electron microscopy (SEM).
¶
A numerical analysis was conducted, using the experimental results from this study, to
further explain the basic toughening mechanisms and fracture behaviour in the materials.
The aim of the analysis was to examine the influence of the particles on the plastic zone
size that develops in front of the crack tip, and the interaction between the particles
and the crack tip. For this purpose FEA elastic-plastic crack propagation models were
employed. Good agreement with the experimental data was found.
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Thomas, Martin Paul. "Microstructure/property relationships in 2124 Al alloy and Al/SiC particulate metal matrix composite." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339487.
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Renova, Elvia Paola. "Simulated annealing algorithms for the optimization of particulate composite structures analyzed by X-FEM." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2008. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Hayes, Ian. "Microstructural characterisation and heat treatment refinement of a particulate reinforced aluminium metal matrix composite." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8077/.
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The purpose of this work was to determine the microstructure and secondary phase distribution in the TiB2 particulate reinforced Al-4.5Cu A205 alloy. This was extended to sand, investment and die casting techniques with the overall aim of optimising the existing solution heat treatment protocol for a variety of possible starting conditions. Additional work was aimed at determining a relationship between TiB2 additions and the observed globular microstructure. Hardness testing, DSC analysis, EDS and tensile testing were used to determine the effectiveness of heat treatment. It was found that a 4hr solution treatment at 538oC did not produce significantly different results from a 44hr, four step treatment process. As the diffusion behaviour of Cu was judged to be the most important factor affecting solution heat treatment, a simple microstructural model of typical A205 grain structures was proposed. The model was found to operate on similar timescales to those observed from experimental testing of A205 but was limited by idealised phase structures. The castability of A205 was determined using fluidity and hot tearing experiments. The better than expected castability was attributed to enhanced feeding brought about by the globular structure of A205.
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Samer, Nassim. "Synthèse réactive de Composites à Matrice Métallique." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1057/document.
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En raison de leur propriétés spécifiques élevées, par rapports aux alliages légers, les Composites à matrice métallique (CMM) représentent des matériaux d'intérêt pour des applications de haute technologie dans les domaines aéronautique et aérospatiale. Les CMM les plus couramment utilisés sont à renfort particulaire, ou PRMMC, et à matrice Al en raison de leur faible densité. Cette thèse porte sur la mise au point de PRMMC à renfort nanométrique par une voie de synthèse réactive globale. En raison des normes encadrant l’usage des nanomatériaux et visant à limiter l’exposition des usagers et de l’environnement, la manipulation de poudres de taille nanométrique est coûteuse et problématique dans le cadre d’un usage industriel. La nouvelle voie de synthèse qui a été développée dans le cadre de cette thèse a permis de démontrer la faisabilité de composites à matrice métallique et à renfort particulaire nanométrique, dimension moyenne de 30 nm, sans avoir recourt initialement à des poudres de taille nanométrique. Le procédé étudié consiste en une réaction chimique à haute température entre deux matériaux précurseurs qui conduit à la formation in-situ non seulement du renfort mais aussi de la matrice. Par rapport aux techniques de synthèse classiques, cette technique permet de synthétiser des nanoparticules in situ et d’en contrôler la taille. De plus, la matrice et le renfort étant co produits par la réaction à haute température, l’interface entre les deux phases est exempte de couches d’oxydes, ce qui lui assure une très bonne adhésion. Dans le cadre du projet ANR NanoTiCAl, la faisabilité de cette nouvelle méthode a été étudiée à travers le cas d'un composite à matrice aluminium renforcé par des particules de carbure de titane (TiC). Les synthèses ont été réalisées entre 900°C et 1000°C à partir d’un couple de précurseurs incluant le graphite et un aluminiure de titane (Al3Ti). Le composite obtenu, caractérisé par un taux de renfort élevé de 34wt.%, possède un module de Young de 106 GPa, un allongement maximal à la rupture de 6% ainsi qu’une énergie à rupture de l’ordre de 28 J.cm-3. Ces valeurs démontrent un compromis entre résistance et capacité d’endommagement original et particulièrement intéressant, jamais observé dans la littérature pour des composites d’une teneur en renfort aussi importante. La caractérisation fine de la microstructure du composite ainsi que du renfort TiC après extraction du composite massif, ont permis de mieux comprendre les mécanismes à l’oeuvre dans cette voie de synthèse réactive. Enfin, sur la base de la compréhension obtenue dans le cas du composite Al/TiC, des critères ont été identifiés permettant d’aller vers une généralisation de ce procédé de synthèse. La pertinence de cette généralisation a finalement pu être démontrée par quelques mises en application à d’autres systèmesMetal Matrix Composites (MMCs) have attracted research and industrial attentions as materials for high technological applications in the aeronautic and aerospace industry. The MMCs differ by their high specific mechanical properties compared to light weight alloys. The most commonly used are the Particulate Reinforcement Metal Matrix Composites (PRMMCs), especially the Al based matrices because of their low density.This thesis deals with the reactive synthesis of PRMMCs reinforced by nanoparticles. Because of the standards governing the use of nanomaterials to limit the exposure of users and environment, handling nanoscaled powders is very problematic and expensive in industry. Furthermore, the cost of this kind of processes is very high. This new synthesis route, developed during this thesis, shows the feasibility of PRMMCs reinforced by nanosized particles, with a mean size of 30 nm, without using any starting nanoparticles.The process consists in a chemical reaction at high temperature between precursor materials which leads to form both of the matrix and the reinforcement phase. Compared to conventional synthesis techniques as stir casting, this route allows to synthesis nanoparticles in-situ and to control their size. In addition, the matrix and the reinforcement, which are formed by a reaction at high temperature, have an interface free of oxide layers which assures a good adhesion.In the NanoTiCAl project, the feasibility of this new method is illustrated in the case of an aluminium based composite reinforced by titanium carbide (TiC). The synthesis were realized between 900°C and 1000°C from a couple of precursors including graphite and titanium aluminide (Al3Ti). The resulting composite, characterized by a high reinforcement ratio (34 wt.%), presents a Young’s modulus of 106 GPa, a maximum elongation of 6 % and a high toughness, about 28 J.cm-3. These values represent an uncommon compromise between strength and toughness never seen in the literature regarding to the high content of reinforcement.The characterization of the composite microstructure and of the reinforcement phase, after extraction of the solid composite, allowed a better understanding of the reaction mechanism during the reactive synthesis. Finally, based on our understanding of the Al-TiC composite, criteria have been identified to generalize this synthesis process. This generalization was demonstrated with success in other systems
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Kitey, Rajesh Tippur Hareesh V. "Microstructural effects on fracture behavior of particulate composites investigation of toughening mechanisms using optical and boundary element methods /." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Spring/doctoral/KITEY_RAJESH_50.pdf.
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Serdarli, Osman. "A Study On The Production And Properties Of In-situ Titanium Diboride Particulate Reinforced Aluminum A 356 Alloy Composite." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613380/index.pdf.
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TiB2 particle reinforced aluminum matrix composites have been the subject of several investigations. An M.Sc. thesis on production of TiB2 reinforced aluminum composites by reaction between liquid aluminum and B2O3 and TiO2 dissolved in cryolite has been completed in this Department in 2005. This study is a continuation of the mentioned M.Sc.study. Composition of the starting cryolite-B2O3-TiO2 system, temperature and time were used as experimental variables. The resulting composite was squeeze cast and its microstructure was examined. Mechanical properties of the produced composite were measured and how mechanical properties of the composite vary with TiB2 content of the composite was determined.
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Katepalli, Nagababu Lankarani Hamid M. "Parametric study of stress concentration in bolted lap joints between particulate metal matrix composite materials." Diss., A link to this thesis in SOAR, 2006. http://soar.wichita.edu/dspace/handle/10057/660.
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Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering."December 2006. Title from PDF title page (viewed on August 17, 2007). Thesis adviser: H.M. Lankarani. Includes bibliographic references (leaves 84-86).
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SETHI, VARUN. "Effect of Aging on Abrasive Wear Resistance of Silicon Carbide Particulate Reinforced Aluminum Matrix Composite." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1191951786.
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Degnan, Craig Cambell. "Processing and wear properties of a (W,Ti)C particulate reinforced ferrous-based metal matrix composite." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285253.
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Trautmann, Radoslav. "Effect of Composition on Adhesion Strength Between Particle Filled Composite and Fiber Reinforced Composite." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-233308.
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Disertační práce se zabývala vlivem adheze mezi vláknovým (FRC) a částicovým (PFC) kompozitem a složením obou komponent na mechanické vlastnosti a způsob porušování modelových bi-materiálových kompozitních těles při statickém namáhání. Zkoumán byl také vliv způsobu přípravy bi-materiálového kompozitního tělesa na pevnost adheze mezi jeho kompozitními komponentami. K hodnocení mechanických vlastností bi-materiálových PFC/FRC těles byl použit jak 3 tak 4-bodový ohybový test za pokojové teploty a relativní vlhkosti 70%. Modifikovaný vytrhávací test byl použit k měření smykové pevnosti adheze mezi vláknovým a částicovým kompozitem. Tyto výsledky byly korelovány s výsledky ze strukturní a fraktografické analýzy (TGA, SEM). Experimentální data byla poté analyzována pomocí existujících mikromechanických modelů a byl nalezen vztah mezi tuhostí modelových bi-materiálových těles, složením a geometrií uspořádání jejich komponent a pevností adheze mezi těmito komponentami. Na základě těchto výsledků byl navržen optimální způsob vrstvení a přípravy PFC/FRC bimateriálových těles. Navržené postupy byly použity k přípravě a pre-klinickým testům nosných konstrukcí zubních můstků.
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Kirugulige, Madhusudhana S. "A study of mixed-mode dynamic fracture in advanced particulate composites by optical interferometry, digital image correlation and finite element methods." Auburn, Ala., 2007. http://repo.lib.auburn.edu/07M%20Dissertations/KIRUGULIGE_MADHUSUDHANA_29.pdf.
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Liong, Silvia. "A Multifunctional Approach to Development, Fabrication, and Characterization of Fe3O4 Composites." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7640.
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A unique approach for lightweight multifunctional composites was developed using Fe3O4 nanoparticles and polypyrrole-coated Fe3O4 particles as fillers. Fe3O4 particles are a good candidate for filler in a multifunctional composite system because they can reinforce mechanical properties of a polymer matrix and impart magnetic properties into a composite. Polypyrrole coating on Fe3O4 particles was utilized to incorporate electrical conductivity to the properties of composites. The effects of filler size and filler content were studied on both the mechanical and electromagnetic properties. Fe3O4 nanoparticles improved fracture toughness, but they compromised strength and modulus. Polypyrrole-coated Fe3O4 has potential for multifunctional material applications because the coating allows for concurrent increase in magnetic permeability and electrical conductivity in a composite. The polypyrrole coating also improved the strength of the composite. Fe3O4 nanoparticles were a major part of this work from their synthesis to their application in composites. The surface effect on magnetic properties was analyzed for Fe3O4 nanoparticles, resulting in a more accurate calculation of the magnetically dead layer thickness than previously reported. The results from this work contributed to further understanding of synthesis and characterization of magnetic nanoparticles, fabrication and characterization of nanocomposites, and design and development of lightweight multifunctional materials. Although the properties of the fabricated composites require further improvement, the methodology and approach provide a basis for future work in development of lightweight multifunctional composites.
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Bernardeau, Fabien. "Stratégies et scénarii de valorisation de déchets phénoplastes au sein de matrices thermoplastiques." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTS033/document.
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Cette thèse, réalisée en partenariat avec deux industriels, a pour objectif de mettre au point une voie de valorisation matière des résines phénoplastes (bakélite) issues de gisement de déchets plastiques. En effet, ce type de résine (thermodurcissable) n’est pour l’instant pas valorisé en fin de vie et finit en enfouissement. Pour répondre aux attentes législatives (directive DEEE, mais aussi VHU dans l’automobile), qui imposent un quota de recyclage (réutilisation et valorisation matière) et de valorisation énergétique minimum pour les déchets en fin de vie, il parait important de développer des procédés de régénération de ces plastiques ainsi que de trouver des domaines d’application pour leur utilisation en tant que matière première secondaire.Enedis, dans le cadre du déploiement de ces nouveaux compteurs électriques, collecte les anciens compteurs et équipements installés et cherche une solution de recyclage adaptée. Une partie de ce gisement important de déchets est constituée de plastiques de tous types en mélange, et en particulier de bakélite. Le travail de cette thèse s’est concentré sur le traitement et la régénération de ce gisement.Dans un premier temps, un schéma de démantèlement et de tri de ce gisement varié a été mis en place. Il est basé sur une étude des matières présentes dans le gisement, en particulier plastiques. La présence d’additifs est également évaluée, en particulier celle de substances contrôlées comme les retardateurs de flamme halogénés, le cadmium, etc. L’objectif était d’optimiser le procédé de séparation des matières en vue d’obtenir des gisements de matières régénérées de pureté suffisante pour le réemploi, tout en limitant la présence d’additifs contrôlés pour respecter les concentrations maximales légales.Pour valoriser les résines phénoplastes issues de ce gisement, la voie envisagée consiste à réutiliser cette matière sous forme de charges incorporées au sein de matrices thermoplastiques (éventuellement régénérées). Pour ce faire, une étude de la transformation de la bakélite par broyage pour obtenir un produit de granulométrie très fine (micronisation) a été réalisée. La distribution granulométrique, la morphologie et son état physico-chimique de surface ont été évaluées en fonction des paramètres du procédé. Après incorporation à différents taux de charge dans des matrices thermoplastiques, les propriétés mécaniques en quasi-statique et dynamique des composites ont été évaluées. La fonctionnalisation des charges/matrices et l’incorporation d’agents compatibilisants ont permis d’améliorer la cohésion des interfaces. Une modélisation par homogénéisation a été réalisée pour rendre compte de l’influence des différentes variables sur la tenue mécanique des composites.Le comportement au feu des composites formulés a également été étudié. Du fait de la stabilité thermique élevée de la bakélite et du taux de char important formé lors de sa combustion, il est envisagé d’utiliser les charges phénoplastes comme donneur de carbone dans la formulation d’un système retardateur de flamme intumescent. Des additifs appropriés, comme une source d’acide et un agent gonflant, seront évalués pour la formulation du systèmeThe main goal of this PhD project, born from a partnership between EMA, APR2 and Enedis, was to develop a material recycling solution for phenolic molding compound (PMC, or Bakelite). Indeed, these types of thermoset material are hardly valorized and end up in landfill, mostly because of the lack of technically and economically viable solutions for recycling.Phenolic molding compound material are present in large amount in End of Life (EOL) electrical meter waste stream. Therefore, Enedis committed to find a valorisation scheme for these materials. This PhD work is aimed to develop a recycling process for PMC issued from this waste stream.Firstly, a dismantlement and sorting scheme was designed. It is based on the study of the waste stream material composition – in particular the plastic stream. The presence of regulated substances (such as halogenated flame retardant, etc.) in plastic formulations was assessed. The objective was to optimize the separation process to recover materials with a high degree of purity.The proposed recycling solution consists in using the PMC as a functional filler in a thermoplastic matrix. To do so, a comminution scheme was developed to reduce the size of the PMC part. The particle size distribution, morphology and surface chemistry of the obtained products were characterized. Quasi-static and dynamic mechanical properties of composite materials incorporating micronized PMC were determined. Various coupling schemes were studied in order to increase the adhesion between filler and matrix. The mechanical behaviour of the composite materials was also modelized using finite element methods.The fire behaviour of the composite material incorporating PMC filler was also studied. Because of the high thermal stability and high char yield of phenolic molding compound, its potential use as a carbon donor in intumescent flame retardant formulations was finally assessed
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Lacondemine, Tanguy. "Initiation et propagation d'une fissure dans un composite particulaire à matrice verre : expérimentation et analyse numérique." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S094.
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L’inclusion de particules dans un verre offre la possibilité de fonctionnaliser et de renforcer le matériau. Ici, le contraste d’absorption au rayon X entre la matrice et les inclusions permet d’analyser les images tomographiques par corrélation d’image, et de mesurer les champs de déplacement lors d’essais mécaniques in-situ. Dans un premier temps, l’initiation et la propagation de fissure par contact ponctuel à la surface sont étudiées grâce à des essais d’indentation Vickers in-situ sous tomographie de rayon X synchrotron. Un modèle analytique décrivant les champs de déplacement (déformation élastique et densification) sous le site d’indentation est validé expérimentalement. Dans un second temps, la ténacité de composites particulaires à matrice verre est déterminée grâce à la méthode SEPB. L’évolution de KI est mesurée au cours de la phase finale de flexion trois points par corrélation d’image. Enfin, des essais DCDC permettent de faire se propager une fissure de manière stable. Une observation optique met en évidence les interactions entre la fissure et les inclusions, et l’évolution de KI au cours du chargement est également mesurée. La tomographie de rayon X in-situ donne accès à la distribution de KI le long du front de fissure et l’influence du T-stress sur la propagation de la fissure est discutéeThe inclusion of particles in a glass offers the possibility of functionalizing and strengthening the material. Here, the X-ray absorption contrast between the matrix and inclusions allows tomographic images to be analyzed by image correlation, and displacement fields to be measured during in-situ mechanical tests. Initially, the initiation and propagation of cracking by sharp contact loading at the surface is studied using Vickers in-situ indentation tests under synchrotron X-ray tomography. An analytical model describing the displacement fields (elastic deformation and densification) under the indentation site is then experimentally validated. In a second step, the toughness of glass matrix particulate composites is determined using the SEPB method. The evolution of KI is measured during the final three-point bending phase by image correlation. Finally, DCDC tests allow a crack to propagate in a controlled way. An optical observation highlights the interactions between the crack and inclusions and the evolution of KI during loading is also measured. In-situ X-ray tomography provides access to the distribution of KI along the crack front and the influence of T-stress on crack propagation is discussed
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Gallican, Valentin. "Homogenization estimates for polymer-based viscoelastic composite materials." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS543.
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Cette thèse porte sur l’étude de la réponse harmonique macroscopique de matériaux composites viscoélastiques à base polymère. Nous nous intéressons tout d’abord à l’étude de matériaux composites à renforts particulaires dont la matrice est modélisée à partir de modèles de Zener fractionnaires et contient des particules sphériques élastiques. Le comportement asymptotique du module complexe macroscopique est étudié à l’aide de principes de stationnarité appliqués à la viscoélasticité complexe. Il est à noter que quatre conditions exactes sont obtenues sur les modules de stockage et de perte. Les deux premières correspondent aux réponses élastiques découplées à haute et basse fréquences, tandis que les deux autres résultent du couplage viscoélastique caractérisant la phase de transition vitreuse. A partir de celles-ci, nous développons des modèles micromécaniques viscoélastiques approchés sur toute la gamme de fréquences. Les modèles approchés font intervenir des développements en séries de Dirichlet-Prony afin d’estimer le comportement viscoélastique macroscopique. Ces derniers sont présentés à l’aide du schéma GSC dans le cas de constituants isotropes et comparés à des simulations FFT réalisées sur des microstructures périodiques pour différentes fractions volumiques de particules. Nous nous attachons ensuite à modéliser la réponse d’explosifs composés de poudres de TATB avec adjonction d’une phase polymère par une approche micromécanique en deux étapes. Nous commençons par étudier l’élasticité effective de polycristaux de TATB sans liant en fonction de nombreux paramètres morphologiques. Le comportement viscoélastique macroscopique est ensuite approché par des modèles micromécaniques et comparé à des simulations FFT et des données expérimentalesThis Ph.D. work deals with the description of the time harmonic response of polymer-based viscoelastic composite materials. On the one hand, the emphasis is put on particulate-reinforced composite materials whose matrix is defined by fractional Zener models containing elastic spherical particles. The asymptotic behaviour of the overall complex moduli is studied by resorting to stationary principles for complex viscoelasticity. Four exact conditions on the storage and loss moduli are obtained. Two of them classically correspond to the uncoupled elastic responses at low and high frequencies while the two others result from the viscoelastic coupling in the transient regime. These conditions only involve the strain fields solutions of asymptotic elastic problems. Based on these conditions, we propose to develop approximate viscoelastic homogenization models for the whole frequency range. They classically make use of Dirichlet-Prony series to estimate the overall viscoelastic behaviour. Such models are presented by means of the GSC scheme for isotropic constituents and compared to FFT full-field computations carried out on periodic microstructures with various volume fractions of particles. On the other hand, we focus on the modeling of TATB-based pressed polymer-bonded explosives seen as jointed polycrystals by means of two-step multiscale modeling. We first investigate the effective elasticity of binder-free TATB-based polycrystals with respect to various morphological parameters. Afterwards, the overall viscoelastic behaviour is assessed by making use of mean-field schemes and compared to FFT full-field computations and experimental data
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Humphreys, Matthew. "Development and Structural Investigation of Monocoque Fibre Composite Trusses." Queensland University of Technology, 2003. http://eprints.qut.edu.au/15898/.
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Fibre composite materials are gaining recognition in civil engineering applications as a viable alternative to traditional materials. Their migration from customary automotive, marine, aerospace and military industries into civil engineering has continued to gain momentum over the last three decades as new civil engineering applications develop. The use of fibre composite materials in civil engineering has now evolved from non-structural applications, such as handrails and cladding, into primary structural applications such as building frames, bridge decks and concrete reinforcement. However, there are issues which are slowing the use of fibre composite materials into civil engineering. Issues include high costs, difficulties in realising potential benefits, general lack of civil engineers' familiarity with the material and relatively little standardisation in the composites industry. For composites to truly offer a viable alternative to traditional construction materials in the civil engineering marketplace, it is essential that these issues be addressed. It is proposed that this situation could be improved by demonstrating that potential benefits offered by composites can be achieved with familiar civil engineering forms. These forms must be well suited to fibre composite materials and be able to produce safe and predictable civil engineering structures with existing structural engineering methods. Of the numerous structural forms currently being investigated for civil engineering applications, the truss form appears particularly well suited to fibre composites. The truss is a familiar structural engineering form which possesses certain characteristics that make it well suited to fibre composite materials. In this research a novel monocoque fibre composite truss concept was developed into a working structure and investigated using analytical and experimental methods. To the best of the author's knowledge the research presented in this thesis represents the first doctoral research into a structure of this type. This thesis therefore presents the details of the development of the monocoque fibre composite (MFC) truss concept into a working structure. The developed MFC truss was used as the basis for a detailed investigation of the structural behaviour of the MFC truss elements and the truss as a whole. The static structural behaviour of the principal MFC truss elements (tension members, compression members and joints) was investigated experimentally and analytically. Physical testing required the design and fabrication of a number of novel test rigs. Well established engineering principles were used along with complex finite element models to predict the behaviour of the tested truss elements and trusses. Results of the theoretical analysis were compared with experimental results to determine how accurately their static structural behaviour could be predicted. It was found that the static structural behaviour of all three principal truss elements could be accurately predicted with existing engineering methods and finite element analysis. The knowledge gained from the investigation of the principal truss elements was then used in an investigation of the structural behaviour of the MFC truss. Three full-scale MFC trusses were fabricated in the form of conventional Pratt, Howe and Warren trusses and tested to destruction. The investigation included detailed finite element modelling of the full-scale trusses and the results were compared to the full-scale test results. Results of the investigation demonstrated that the familiar Pratt, Howe and Warren truss forms could be successfully manufactured with locally available fibre composite materials and existing manufacturing technology. The static structural behaviour of these fibre composite truss forms was accurately predicted with well established engineering principles and finite element analysis. A successful marriage between fibre composite materials and a civil engineering structure has been achieved. Monocoque fibre composite trusses have been developed in the familiar Pratt, Howe and Warren truss forms. These structures possess characteristics that make them well suited to applications as primary load bearing structures.
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Jahani, Babak. "Development of an Advanced Composite Material Consisting of Iron Matrix Reinforced with Ultra High Temperature Ceramic Particulate (TiB2) with Optimum Properties." Thesis, North Dakota State University, 2016. https://hdl.handle.net/10365/28089.
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This study was intended to investigate the mechanical properties and microstructure of iron based composite reinforced by ultra high temperature ceramics fabricated by powder metallurgy technique. The fabrication parameters were optimized and composite samples with different volume fraction of TiB2 were fabricated and were subjected to different mechanical tests. The results indicated improving in mechanical properties of Fe-TiB2 composites by increasing the volume fraction of TiB2 up to 20 vol%. More TiB2 particles didn?t improve the mechanical properties of composite, instead adversely affected it due to increasing the chance of agglomeration and porosity in entire microstructure. Another finding showed the twofold characteristic of TiB2 on mechanical properties of composite via increasing the hardness and decreasing the bulk density of composite. Finite Element Analysis (FEA) have also been performed on microstructural based developed models to simulate failure of composites. Numerical simulation results could verify the experimental results.
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Gomes, Márcia Aparecida. "Caracterização mecânica e microestrutural de compósitos de matriz metálica Al/SiCp e Al/Al2O3p obtidos via interação por laminação acumulativa." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-01032016-131333/.
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Compósitos de matriz metálica (CMM) reforçados com dois tipos de particulado cerâmico foram produzidos por meio do processo ARB (Accumulative Roll Bonding) a fim de estudar os efeitos destes no que diz respeito às propriedades mecânicas e microestruturais. ARB é um processo de deformação plástica severa aplicada originalmente a uma pilha de lâminas metálicas, a qual é laminada, seccionada em duas metades, as quais são empilhadas e novamente laminadas, e assim por diante, desenvolvido com o propósito de reduzir o tamanho de grão e aumentar a resistência mecânica do produto final. O processo é econômico e capaz de produzir de folhas ultrafinas a placas espessas, sem que haja restrição de quantidade. Confeccionou-se CMM de alumínio reforçados com partículas de carbeto de silício (Al+SiCp) e alumina (e Al+Al2O3p) com granulometria média de 40µm, as quais foram caracterizadas microestruturalmente e ensaiadas em tração até a falha, cuja análise foi conduzida via microscopia eletrônica de varredura. Ambas as amostras obtiveram ganho em sua resistência mecânica, comparadas ao alumínio monolítico (sem adição de partículas de reforço) e alumínio recozido. Foram ensaiados em tração corpos de prova com e sem presença de entalhe, sendo que as peças entalhadas apresentaram comportamento esperado de aumento de resistência mecânica e baixo alongamento e fratura de aspecto frágil. De acordo com análise feita por fratografia houve boa ancoragem e dispersão das partículas de reforço na matriz.Metal matrix composite (CMM) reinforced with two types of ceramic particles have been produced through the process ARB (Accumulative Roll Bonding) in order to study their effect as regards the mechanical and microstructural properties. ARB is a severe plastic deformation process originally applied to a stack of metal sheets, which is laminated, sectioned into two halves, which are stacked and rolled again, and so on, developed with the purpose of reducing the grain size and increase the mechanical strength of the final product. The process is economical and capable of producing ultrafine sheets to thicker plates without much restriction. Were fabricated CMM of the aluminum reinforced with particles of silicon carbide (Al + SiCp) and alumina (and Al + Al2O3p) with an average particle size of 40μm, which are characterized microstructurally and tested in tension until failure, whose analysis was conducted via scanning electron microscopy. Both samples were successful in its mechanical strength compared to the monolithic aluminum (without addition of reinforcing particles) and annealed aluminum. They were tested for tensile specimens with and without the presence of notch, and the carved pieces showed strength-enhancing behavior and low elongation and frail fracture. According to analysis by fractography was good anchoring and reinforcement particles dispersed in the matrix.
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Gardiner, Peter Christopher. "Microstructural damage and mechanical properties of a metal matrix composite (Al-particulate SiC) and an intermetallic (titanium aluminide) under various deformation regimes." Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287656.
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Máša, Bohuslav. "Numerické modelování chování částicového kompozitu se sesíťovanou polymerní matricí." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229477.
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The master's thesis deals with the determination of macroscopic behavior of a particulate composite with cross-linked polymer matrix under tensile load. The main focus of thesis is estimation of mechanical properties of a composite loaded by tensile loading using numerical methods (especially finite elements method). Investigated composite is composed of matrix in a rubbery state filled by alumina-based particles (Al2O3). Hyperelastic properties of the matrix have been modeled by the Mooney-Rivlin material model. Different compositions of particles, their different shape, orientation and different volume fractions have been considered. For all these characteristics of composite numerical models have been developed. The damage mechanisms of the matrix have also been taken into account. Results of numerical analyses have been compared with experimental data and good agreement between numerical models with damage mechanisms of matrix and experimental data has been found.
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Godbole, Chinmay. "The Influence of Reinforcement on Microstructure, Hardness, Tensile Deformation, Cyclic Fatigue and Final Fracture behavior of two Magnesium Alloys." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1321633235.
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Dubernet, Marion. "Mécanoluminescence de composites particulaires à matrice vitreuse." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S120/document.
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La mécanoluminescence (ML) est un phénomène physique qui se traduit par l’émission de lumière suite à l’application d’une contrainte mécanique. Dans le cadre de ce travail de thèse, les matériaux mécanoluminescents vont être utilisés afin de visualiser les contraintes qui peuvent être générées dans un verre lors d’une sollicitation mécanique. Nous avons élaboré un composite constitué de particules mécanoluminescentes SrAl2O4:Eu, Dy incorporées dans une matrice vitreuse. Nous nous sommes ensuite intéressés à l’origine et au mécanisme de ce phénomène en réalisant une étude mécanique sur le composite. Ces essais nous ont permis de développer un modèle empirique qui relie la contrainte à l’intensité émise. La structure cristalline des particules jouant un rôle clef dans la ML, nous avons également mené une étude théorique de cette structure, ce qui nous a permis de corréler les observations macroscopiques faites sur le composite aux phénomènes ayant lieu à une échelle atomiqueMechanoluminescence (ML) is the phenomenon of light emission generated by a mechanical loading. Mechanoluminescent materials were used to visualize the stress in glasses during mechanical loadings. A mechanoluminescent particulate glass composite was synthesized by incorporating SrAl2O4:Eu, Dy particles in a glass matrix for the first time. We performed a mechanical study on the composite to determine the origin and the mechanism of this phenomenon. We developed a theoretical model which accurately predicts the ML intensity changes induced by a complex mechanical loading. The crystal structure of the particles has a key role in the ML and we carried out a theoretical study of this structure to correlate the macroscopic observations made on the composite to the phenomena which occur at the atomic scale
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Huczala, Vít. "Vliv fyzikální úpravy sráženého CaCO3 na vlastnosti kompozitu na bázi PP." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217005.
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The diploma thesis deals with study of system of polypropylene and inorganic filler. As filler was used commercially available particulate filler CaCO3 termed NPCC 201. The objective of the study was a surface plasma treatment of filler in order to obtain composite based on polypropylene. Mechanical properties of this composite will show significantly greater value than basic matrix. The filler was treated in dielectric barrier plasma discharge by atmospheric pressure. The characterization of filler was performed before and after plasma treatment by x-ray photoelectron spectroscopy (XPS), electron microscope (SEM) and sedimentation analysis. The distribution of particle size was measured by laser diffraction and by dynamic light scattering. The composite materials with various weight concentration of filler were prepared in POLYMER INSTITUTE BRNO by using the twin-screw extruder and the test specimens were prepared by the injection molding technology. Their mechanical properties was studied by using of short and long-term tests. The uniaxial creep testing in tension was used for study of long-term behavior of composites.
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El-Gallab, Mariam S. "Machining of particulate metal matrix composites." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0030/NQ66206.pdf.
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Riaz, Shahid. "Titanium based composites containing particulate carbides." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264184.
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Murphy, Angela Mary. "Clustering in particulate metal matrix composites." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242540.
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Muhaidi, Abed. "Fracture behaviour of particulate-reinforced glass composites." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413009.
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Khanbareh, Hamideh. "Expanding the functionality of piezo-particulate composites." Thesis, University of Bath, 2016. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715258.
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Islam, Md. "Computational modelling of particulate composites using meshless methods." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/13332/.
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This thesis deals with the numerical simulation of particulate composites using one of the more stable and accurate meshless methods namely the element free Galerkin (EFG) method. To accurately describe the material inhomogeneities present in particulate composites, an extrinsic enrichment function is incorporated into the approximation of the EFG method which produces more versatile, robust and effective computational methodology. The effectiveness of the proposed numerical model is then investigated by employing the model to analyse different configurations of particulate composites. The accuracy and efficiency of this enriched EFG method are studied numerically by comparing the results obtained with the available analytical solutions and other numerical techniques. Further, it is demonstrated that the method developed in this work has the potential to efficiently model syntactic foam, a type of particulate composites. This is illustrated by performing multi-scale modelling using homogenisation technique which confirms satisfactory comparison of the numerical method with experimental results. To further explore the applicability of the developed methodology, an enriched or extended finite element method (XFEM) based technique, is applied to study crack inclusion and interaction of crack propagation with matrix and particles within particle reinforced composite material.
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Knight, Matthew G. "Numerical modelling of particulate and fibre reinforced composites." Thesis, Brunel University, 2002. http://bura.brunel.ac.uk/handle/2438/7387.
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This thesis presents research into the micromechanical modelling of composite materials using numerical techniques. Composite materials are generally examined from two points of view: macromechanics and micromechanics, owing to their inherent heterogeneous nature. In this research, the material behaviour is examined on a microscopic scale, as the properties of interest, i.e. strength and toughness, are dependent on local phenomena. In general, the strength and toughness of composite materials are not as well understood as the simpler elastic properties, because in many cases the modes of failure under a given system of external load are not predictable in advance. Previous research in this field has typically involved specially designed experiments, theoretical/statistical studies, or the use of numerical models. In this study, advanced implementations of numerical methods in continuum mechanics, i.e. the boundary element and the finite element methods are employed to gain a greater understanding of composite behaviour. The advantage of using numerical methods, as opposed to experimental studies, is that the geometric and material characteristics can be investigated parametrically, in addition to the reduced time and expense involved. However, to model the complete behaviour of real composites is still not possible, due to the degree of complexity and uncertainty involved in modelling the various mechanisms of damage and failure, etc. and also due to the immense computational cost. Therefore, simplified models must be employed which are limited by their assumptions. For the preliminary studies within this thesis, geometrically simplified models are presented to provide an understanding of the influence of embedding second phase inclusions on the local stress fields, and also to validate the numerical techniques with readily available analytical solutions. These models are then extended to accommodate additional phenomena, such as inclusion interaction, spatial inclusion arrangement, material formulation, i.e. consisting of two- and three-phases of various material properties. The influence of such factors on the local stress concentrations, which play an important role in determining the strength of the composite, is analysed through a series of parametric studies. The localised toughening of composites is also considered through novel investigations into the interaction between a propagating crack with inclusions and microcracks. Through the development of the numerical models a more realistic representation of composite behaviour is achieved, which in tum, provides an improved knowledge of the factors that control strength and toughness. Such information is invaluable to composite material designers, who presently rely heavily on experimental studies to develop composite materials.