Dissertations / Theses on the topic 'Ceramic matrix composite'
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Grosskopf, Paul P. "Mechanical behavior of a ceramic matrix composite material." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/42214.
Full textMonolithic ceramic materials have been used in industry for hundreds of years. These materials have proven their usefulness in many applications, yet, their potential for critical structural applications is limited. The existence of an imperfection in a monolithic ceramic on the order of several microns in size may be critical, resulting in catastrophic failure. To overcome this extreme sensitivity to sman material imperfections, reinforced ceramic materials have been developed. A ceramic matrix which has been reinforced with continuous fibers is not only less sensitive to microscopic flaws, but is also able to sustain significant damage without suffering catastrophic failure.
A borosilicate glass reinforced with several layers of plain weave silicon carbide cloth (Nicalon) has been studied. The mechanical testing which was performed included both flexural and tensile loading configurations. This testing was done not only to determine the material properties, but also to initiate a controlled amount of damage within each specimen.
Several nondestructive testing techniques, including acousto-ultrasonics (AU), were performed on the specimens periodically during testing. The AU signals were monitored through the use of an IBM compatible personal computer with a high speed data acquisition board. Software has been written which manipulates the AU signals in both the time and frequency domains, resulting in quantitative measures of the mechanical response of the material.
This paper will compare the measured AU parameters to both the mechanical test results and data from other nondestructive methods including ultrasonic C-scans and penetrant enhanced X-ray radiography.
Master of Science
Davies, C. M. A. "Failure mechanisms in glass-ceramic matrix composite laminates." Thesis, University of Bath, 1994. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387305.
Full textMarriner-Edwards, Cassian. "The development of fibre-reinforced ceramic matrix composites of oxide ceramic electrolyte." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:3af11d08-c0d8-429b-8eab-d2befc83ea74.
Full textLyons, Jed S. "Micromechanical studies of crack growth in ceramic matrix composite." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/16086.
Full textDunyak, Thomas John. "Properties and performance of a ceramic composite component." Diss., This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-07282008-134634/.
Full textEllerby, 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.
Full textBulsara, Vatsal N. "Effects of fiber spatial distribution and interphase on transverse damage in fiber-reinforced ceramic matrix composites." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/21429.
Full textBischoff, Matthew Lee. "CHARACTERIZATION OF CERAMIC MATRIX COMPOSITE MATERIALS USING MILLIMETER-WAVE TECHNIQUES." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1362655198.
Full textTrandel, Barbara Dawn. "Nondestructive evaluation of a high temperature ceramic matrix composite material." Thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-01312009-063125/.
Full textYang, Fan. "Oxidation and mechanical damage in unidirectional SiC/Si#N# composite at elevated temperatures." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/19057.
Full textAldridge, Matthew. "Aspects of the processing, mechanical properties and thermal shock behaviour of a ductile particle toughened alumina." Thesis, University of Surrey, 1996. http://epubs.surrey.ac.uk/605/.
Full textWest, Grant. "Microstructure and mechanical performance of SiC/BMAS glass-ceramic matrix composite." Thesis, University of Warwick, 1997. http://wrap.warwick.ac.uk/66932/.
Full textGoff, Adam Carter. "Modeling and Synthesis of a Piezoelectric Ceramic-Reinforced Metal Matrix Composite." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/10143.
Full textMaster of Science
King, Harry C. III. "Automation of CVI equipment for laminated matrix composite fabrication." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/19509.
Full textTang, Chao. "Modelling of Thermo-Mechanical Behaviour of Ceramic Matrix Composite Tows and Laminates." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509397.
Full textPryce, A. W. "Matrix cracking and stress/strain behaviour of continuous fibre ceramic composite laminates." Thesis, University of Surrey, 1991. http://epubs.surrey.ac.uk/843150/.
Full textAl-Joubory, Kassim M. "Fibre-matrix reaction in composite ceramics based on alumina, titania, and zirconia matrices." Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329508.
Full textHam, Alexander. "High temperature erosive wear of a continuous fibre reinforced glass-ceramic matrix composite." Thesis, University of Surrey, 1998. http://epubs.surrey.ac.uk/804413/.
Full textMariappan, L. "In-Situ Synthesis Of A12O3_ZrO2_SiCw Ceramic Matrix Composites By Carbothermal Reduction Of Natural Silicates." Thesis, Indian Institute of Science, 2000. https://etd.iisc.ac.in/handle/2005/215.
Full textMariappan, L. "In-Situ Synthesis Of A12O3_ZrO2_SiCw Ceramic Matrix Composites By Carbothermal Reduction Of Natural Silicates." Thesis, Indian Institute of Science, 2000. http://hdl.handle.net/2005/215.
Full textButts, Mark D. "Nondestructive examination of nicalon fiber composite preforms using x-ray tomographic microscopy." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/19959.
Full textLudford, Nicholas Philip. "An investigation into the thermal aging of an all oxide ceramic matrix composite." Thesis, University of Surrey, 2005. http://epubs.surrey.ac.uk/843476/.
Full textHu, Yile, and Yile Hu. "Peridynamic Modeling of Fiber-Reinforced Composites with Polymer and Ceramic Matrix." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/625367.
Full textChen, Makan. "A modified sol-gel route to fibre reinforced alumina and mullite composites." Thesis, University of Sheffield, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326846.
Full textCottet, Arnaud J. "Modelling of ceramic matrix composite microstructure using a 2-D fractal spatial particle distribution." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/12928.
Full textDearn, Sophie Clare. "Development of a novel oxide-oxide ceramic matrix composite for high temperature structural applications." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/5924/.
Full textGHOSH, DIPANKAR. "CRACK PROPAGATION AND FRACTURE RESISTANCE BEHAVIOR UNDER FATIGUE LOADING OF A CERAMIC MATRIX COMPOSITE." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1019491575.
Full textHalverson, Howard Gerhard. "Durability of Ceramic Matrix Composites at Elevated Temperatures: Experimental Studies and Predictive Modeling." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/27834.
Full textPh. D.
Smith, Craig Edward. "Monitoring Damage Accumulation In SiC/SiC Ceramic Matrix Composites Using Electrical Resistance." University of Akron / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=akron1249917100.
Full textAKRAM, MUHAMMAD YASIR. "Giunzione di compositi a matrice ceramica a base ossidica." Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2751274.
Full textHerbst, Stephan. "Investigation of a ceramic metal matrix composite functional surface layer manufactured using gas tungsten arc welding." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9191.
Full textMARCHISIO, SILVIA. "Composite Materials reinforced by Carbon Nanotubes." Doctoral thesis, Politecnico di Torino, 2013. http://hdl.handle.net/11583/2506164.
Full textMiller, Ian Timothy. "Probabilistic finite element modeling of aerospace engine components incorporating time-dependent inelastic properties for ceramic matrix composite (CMC) materials." Akron, OH : University of Akron, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=akron1144941702.
Full text"May, 2006." Title from electronic thesis title page (viewed 11/29/2007) Advisor, Vinod Arya; Co-Advisor, Ali Hajjafar; Faculty reader, Shantaram S. Pai; Department Chair, Kevin Kreider; Dean of the College, Ronald F. Levant; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.
Gordon, Neal A. "Material Health Monitoring of SIC/SIC Laminated Ceramic Matrix Composites With Acoustic Emission And Electrical Resistance." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1414835900.
Full textVazquez, Calnacasco Daniel. "All-Oxide Ceramic Matrix Composites : Thermal Stability during Tribological Interactions with Superalloys." Thesis, Luleå tekniska universitet, Materialvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-85513.
Full textTurkyilmaz, Gokhan. "Processing And Assessment Of Aluminum Ceramic Fiber Reinforced Aluminum Metal Matrix Composite Parts For Automotive And Defense Applications." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610751/index.pdf.
Full textC and 800 °
C. In the first part of the thesis, physical and mechanical properties of composite specimens were determined according to the parameters of silicon content of the matrix alloy, infiltration temperature and vol% of the reinforcement phase. X-ray diffraction examination of fibers resulted as the fibers mainly composed of deltaalumina fibers and scanning electron microscopy analyses showed that fibers had planar isotropic condition for infiltration. Microstructural examination of composite specimens showed that appropriate fiber/matrix interface was created together with small amount of micro-porosities. Bending tests of the composites showed that as fiber vol% increases flexural strength of the composite increases. The highest strength obtained was 880.52 MPa from AlSi10Mg0.8 matrix alloy reinforced with 30 vol% Saffil fibers and infiltrated at 750 °
C. Hardness values were also increased by addition of Saffil fibers and the highest value was obtained as 191 HB from vertical to the fiber orientation of AlSi10Mg0.8 matrix alloy reinforced with 30 vol% Saffil fibers. Density measurement revealed that microporosities existed in the microstructure and the highest difference between the theoretical values and experimental values were observed in the composites of 30 vol% Saffil fiber reinforced ones for both AlSi7Mg0.8 and AlSi10Mg0.8 matrix alloys. In the second part of the experiments, insertion casting operation was performed. At casting temperature of 750 °
C, a good interface/component interface was obtained. Image analyses were also showed that there had been no significant fiber damage between the insert and the component.
Graham, Samuel Jr. "Effective thermal condutivity of damaged composites." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/16935.
Full textMossor, Charles W. "Electrical Breakdown of Thermal Spray Alumina Ceramic Applied to AlSiC Baseplates Used in Power Module Packaging." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/33543.
Full textMaster of Science
Moriceau, Julien. "Élaboration de vitrocéramiques et de composites particulaires à matrice vitreuse aux propriétés mécaniques et fonctionnelles innovantes." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S094/document.
Full textIn this thesis, glass-ceramics and glass matrix composites have been developed in order to study the interactions between the crack and the various inclusions. Firstly, the nucleation and volume crystallization of spherulites in a glass of the BaO-Al2O3-SiO2 system were studied. Then, the influence of crystallization on elasticity, hardness and toughness was measured. An increase of these properties due to crystallization was observed. After doping with rare earths oxides, the glass was functionalized by surface crystallization of phosphorescent crystals. Secondly, the influence of a Poisson’s ratio differential (between the matrix and inclusions) on the crack propagation was studied. For this purpose, glassy particulate glass matrix composites have been elaborated by Spark Plasma Sintering (SPS) and studied by Double Cleavage Drilled Compression (DCDC). A deviation of the crack in the vicinity of the glass inclusions has been identified in the case where the Poisson’s ratio of the inclusion is lower than the one of the matrix. In the opposite case, less important deviations were noticed. Finally, nanocomposites functionalized with magnetite (Fe3O4) and gold particles were obtained after a SPS treatment. The properties provided by these particles allowed the material to be heated, respectively, by induction and by laser irradiation. In the second case, after a 10 min laser treatment, a partial healing of indentation cracks could be observed
Mathieu, Sylvain. "Modélisation du comportement mécanique lors du procédé de mise en forme et pyrolyse des interlocks CMC." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0115/document.
Full textManufacture processes modeling of woven fabrics composites is a major stake for state-of-the-art industrial parts, where their usage is intensifying. Control of all the manufacturing stages of ceramic matrix composites, particularly the forming and pyrolysis steps, is essential. Understanding and simulation of the mechanical behavior at each stage is required to optimize the final product performances. Two macroscopic modeling approaches of thick woven fabric reinforcements are detailed: a continuous classical one and a semi-discrete one. An initially orthotropic hyperelastic constitutive law is thus established. This law is based on a phenomenological observation of the main fabric deformation modes, from where physical invariants of the deformation are suggested. The required material parameters identification is explained. A modified version of this law, without any tensile energetic contribution, is implemented in a semi-discrete element where the tensile work is taken into account by bars that discretize the real weaving. Thick woven reinforcements are highly anisotropic materials due to the large ratio between the tensile rigidity and the others. Their numerical modeling highlights spurious phenomena and limitations related to this specificity. The tension locking is firstly tackled. A remedy based on an enhanced assumed strain finite element formulation is suggested for classical continuum and semi-discrete elements. Problems linked to bending-dominated numerical simulations are brought to attention : transverse hourglassing and lack of local bending stiffness. For the transverse hourglassing situation, two stiffening technics are proposed : averaging the dilatation through the whole element or adding a supplementary tangent material rigidity in a specific direction. The local bending stiffness problem is solved by calculating the curvature inside the element by using rotation free plates. The induced bending moment leads to supplementary internal loads. Finally, the elastic springback following the pyrolysis of the polymer matrix with ceramic precursors is modeled. The constitutive behavior is experimentally identified with a transverse isotropic hyperelastic law. Added to the initial reinforcements’ hyperelastic law, with the preformed fabric as reference configuration, the pyrolysis induced deformations can be visualized. This final model is compared with experimental results
Hunt, Richard K. "A transmission electron microscope characterization of sodium sulfate hot corrosion of silicon carbide fiber-reinforced lithium aluminosilicate glass-ceramic matrix composite." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA286164.
Full textJahani, 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.
Full textEl, Yagoubi Jalal. "Effet de l’endommagement mécanique sur les propriétés thermiques de composites à matrice céramique : approche multiéchelle." Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14297/document.
Full textIn this work the relationship between the evolution of damage and the loss of thermal propertiesof Ceramic Matrix Composites is investigated by a multiscale approach. Research are conductedboth experimentally and theoretically. The implemented approach is to consider two significantscales (micro and meso) where different damage mechanisms are operating and then assess theeffect on the effective thermal properties by homogenization techniques.Particular attention has been given to the development of a thorough experimental work combiningvarious characterization tools (mechanical, thermal and microstructural). At the two aforementionedscales, an experimental setup was designed to perform thermal measurements onCMC under tensile test. Thermal diffusivity of minicomposites is estimated using Lock-in thermography.Also, tranverse diffusivity mapping as well as global in-plane diffusivity of woven CMCare determined by suitable rear face flash methods. The evolution of damage is then derived fromacoustic emission activity along with postmortem microstructural observations. Experimental resultsare systematically compared to simulations. At microscale, a micromechanical-based modelis used to simulate the loss of thermal conductivity of a minicomposite under tensile test. At mesoscale,a multiscale Finite ElementModel is proposed to compute the effect of damage on thermalproperties of woven CMC
Marchais, Alexandre. "Etude des mécanismes de montée capillaire du silicium liquide au sein d'une préforme en carbure de silicium." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0025.
Full textThe development of aeronautic engines increased the need in high temperature SiC/SiC composite researches. A standard way to proceed is to infiltrate the matrix by chemical vapor infiltration. Due to their high porosity, their thermal conductivity is generally low. This could lead to strong thermal gradients and an early failure in a harsh environment. To reduce porosity, an alternative process can be used: the infiltration of molten silicon (MI: Melt Infiltration). The aim of this work is to understand all mechanisms occurring during the infiltration of silicon in a fibrous preform composed of SiC Hi-Nicalon S fibers. This process needs a first step which consists in the introduction of SiC particles into the preform before the MI process.First, this work focused on the definition of the porous structure of studied materials and capillarity tests using wetting organic solvent. With the use of Washburn’s law, it was possible to identify pore sizes within the fibrous preform and the granular matrix, and so to predict the capillarity ascent graphs of molten silicon into our material. A second part was devoted to the conception of an infiltration furnace which allows in situ following of the samples weight gain. The correlation between graphs obtained with the Washburn model and the experimental process could be established. Finally, the last part of this work presents partial infiltrations of molten silicon into studied materials which permit to identify capillary mechanisms occurring during the MI process
Nestler, Daisy Julia. "Beitrag zum Thema VERBUNDWERKSTOFFE - WERKSTOFFVERBUNDE." Doctoral thesis, Universitätsbibliothek Chemnitz, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-134459.
Full textComplex property profiles require increasingly advanced composite materials and material compounds, including the rapid deployment of new production technologies, because the monolithic material or a single material can no longer satisfy today's complex requirements. Future material systems are fundamentally important to growth markets, in which they have an economically key position. Tailor-made lightweight materials (tailor-made composites) with an adapted design are needed. These concepts have to be developed to design the optimum combination of components. This requires material-specific knowledge and the ability to make correlations, as well as the design of complex technologies. Continuous large-scale and mass production (in-line, in-situ), thus reducing the costs of previously expensive composite materials and material compounds, is also necessary. The present work spans the entire field of composite materials and material compounds in a comparable and comparative manner and abstract form. A summarizing publication on this still very new, but already broad-based scientific field is not yet available. The separation of the individual, firmly divided groups of the composite materials is the reason for this. Cross-connections are rarely made. The objective of this work is to compensate to some extent for this deficiency. Special consideration is given to definitions and classifications, manufacturing processes and the properties of the materials. Clear structures and overviews are presented. Mapping established and new technologies will contribute to the stability of the terms "mixed material compounds" and "hybrid material compounds". In addition, the problem of recycling and recycling technologies is discussed. In summary, areas for future research and development projects will be specified. Generalized concepts for tailor-made composite materials and material compounds are proposed ("adjusting screw scheme") with an eye toward various production routes, especially for semi-finished products and components, and the associated findings. These general material concepts are applied to own current research projects pertaining to metal-matrix and polymer-matrix composites and hybrid material compounds. Research fields for future projects are extrapolated. Particular attention is paid to hybrid material compounds as the mainstay of future developments in lightweight construction. In-line and in-situ processes play a key role for large-scale, cost- and resource-efficient production
Taillet, Brice. "Procédés alternatifs pour l'élaboration de matériaux composites à matrice céramique." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0203/document.
Full textThe opening of the civil aviation market to ceramic matrix composite materials requires the development of new methods of producing compatible with the production rates and manufacturing costs of the sector.For this purpose, experimental work was conducted to develop a silicon oxynitride matrix (Si2N2O) by combustion synthesis (or SHS), from reactive powders. In recent years, Si2N2O has emerged as a promising new high-temperature ceramic material, characterized by not only good mechanical properties, but also by a higher oxidation resistance than silicon carbide. The underlying basis of SHS relies on the ability of highly exothermic reactions to be self-sustaining and, therefore, energetically efficient. Powders are first milled, dispersed and stabilized in aqueous media, and then impregnated into a fibrous preform composed of the latest generation of silicon carbide fibers (Hi-Nicalon S). SHS reaction is then carried out in a reactor specially designed and dedicated to this study. Particular attention was focused on the optimization of experimental parameters for the synthesis of a Si2N2O based matrix. Silicon metal in a mixture with silica powder was combusted under pressurized nitrogen gas into silicon oxynitride. The pressure and the temperature rise rate were the principal parameters for the composition and microstructure of the matrix. These parameters have been the subject of extensive experimental work to reach a homogeneous matrix with a very high formation rate for silicon oxynitride (more than 90wt%) and with a level of residual porosity lower than 10%. This work was completed by the calculation of the physical properties of the matrix, by the mechanical characterization of the composite material, and finally by a temperature aging test under moist air
Guel, Nicolas. "Comportement mécanique de composites oxydes : Relations procédé-microstructure-propriétés." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI104/document.
Full textThe aim of this thesis is the fine understanding on the influence of the microstructure on oxide-based ceramic matrix composites mechanical properties. These materials are good candidate for new generation of civil aircraft engines. The aim of this work is to establish a relationship between the microstructural defects generated by the manufacturing process and the mechanical behavior of the composite. These heterogeneities seem to influence the appearance and the propagation of damage mechanisms. This study is realized on three kinds of bi-dimensional oxide composites generated from three different manufacturing processes. These processes create three kinds of microstructure. Porosimetric and μ-tomographic analyses allow estimating the distribution of microstructural defects and establish typical microstructure of each oxide composite. Based on these preliminary analyses, mechanical behavior of each kind of oxide composites is studied through several representative scales. On the one hand, mechanical tensile tests are carried out in order to estimate the mechanical properties of the studied materials in the weaving plane. On the other hand, the implementation of in-situ mechanical tests allows the visualization of damage mechanisms appearance and propagation. These observations improve the understanding of the role of microstructural defects on the activation of damage mechanisms. Damage kinetics of each mechanical test are inspected through AE (Acoustic emission) analysis. This monitoring helps to link mechanical behavior with microstructural damage. In parallel with global AE analysis, AE clustering is achieved. These classifications are based on two kinds of AE sensor with different properties. Data fusion from the two sensors is accomplished. This technique allows more robust AE clustering. Cluster labelling is proposed thanks to damage mechanisms observed during in-situ mechanical tests. Damage scenarios are set up owing to macroscopic mechanical test, in-situ analysis and AE labelling. Thus, it is possible to establish the influence of each kind of microstructural defect on oxide-based CMCs mechanical behavior
Maillet, Emmanuel. "Identification des mécanismes d'endommagement et prévision de la durée de vie des composites à matrice céramique par émission acoustique." Thesis, Lyon, INSA, 2012. http://www.theses.fr/2012ISAL0097.
Full textCeramic matrix composites (CMCs) are candidates for use in aeronautical applications for which durability and reliability are key factors. Beyond damage characterization, the current objective is to predict structures lifetime in service conditions. This requires quantifying damage evolution and identifying the various damage mechanisms that are involved. Therefore, it is necessary to characterize materials and define suitable damage indicators. The use or development of models would then allow the evaluation of remaining lifetime based on the analysis of precursory events. In this context, Acoustic Emission (AE) is a suitable technique. Indeed, damage mechanisms release energy in the form of transient elastic waves. Their recording, named Acoustic Emission, allows monitoring material damage growth. This technique is used in this work, which is composed of two complementary parts. The first part aims at identifying the acoustic signature of mechanisms involved in damaging of ceramic matrix composites. This would allow an accurate characterization of damage evolution and would provide indicators for rupture prediction. The second part focuses on the evaluation of remaining lifetime under static fatigue loading based on the energy of AE sources as a measure of damage. The following work shows the contribution of acoustic emission for the analysis of mechanical behaviour and lifetime prediction of CMCs. In the first part, a robust characterization of AE sources and the use of multivariate analysis allow monitoring the growth of each damage mechanism. In the second part, two reproducible phases in the behaviour of CMCs under static fatigue are identified on the AE sources energy release by two real-time indicators. The detection of the second phase and modelling of associated energy release by a power law would allow real-time prediction of the remaining lifetime
Moreno-Gomez, Ismael. "A phenomenological mathematical modelling framework for the degradation of bioresorbable composites." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/278015.
Full textNestler, Daisy Julia. "Beitrag zum Thema VERBUNDWERKSTOFFE - WERKSTOFFVERBUNDE: Status quo und Forschungsansätze." Doctoral thesis, Universitätsverlag Chemnitz, 2012. https://monarch.qucosa.de/id/qucosa%3A20009.
Full textComplex property profiles require increasingly advanced composite materials and material compounds, including the rapid deployment of new production technologies, because the monolithic material or a single material can no longer satisfy today's complex requirements. Future material systems are fundamentally important to growth markets, in which they have an economically key position. Tailor-made lightweight materials (tailor-made composites) with an adapted design are needed. These concepts have to be developed to design the optimum combination of components. This requires material-specific knowledge and the ability to make correlations, as well as the design of complex technologies. Continuous large-scale and mass production (in-line, in-situ), thus reducing the costs of previously expensive composite materials and material compounds, is also necessary. The present work spans the entire field of composite materials and material compounds in a comparable and comparative manner and abstract form. A summarizing publication on this still very new, but already broad-based scientific field is not yet available. The separation of the individual, firmly divided groups of the composite materials is the reason for this. Cross-connections are rarely made. The objective of this work is to compensate to some extent for this deficiency. Special consideration is given to definitions and classifications, manufacturing processes and the properties of the materials. Clear structures and overviews are presented. Mapping established and new technologies will contribute to the stability of the terms "mixed material compounds" and "hybrid material compounds". In addition, the problem of recycling and recycling technologies is discussed. In summary, areas for future research and development projects will be specified. Generalized concepts for tailor-made composite materials and material compounds are proposed ("adjusting screw scheme") with an eye toward various production routes, especially for semi-finished products and components, and the associated findings. These general material concepts are applied to own current research projects pertaining to metal-matrix and polymer-matrix composites and hybrid material compounds. Research fields for future projects are extrapolated. Particular attention is paid to hybrid material compounds as the mainstay of future developments in lightweight construction. In-line and in-situ processes play a key role for large-scale, cost- and resource-efficient production.