Dissertations / Theses on the topic '3D microstructures'
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King, Philip Huw. "Towards rapid 3D direct manufacture of biomechanical microstructures." Thesis, University of Warwick, 2009. http://wrap.warwick.ac.uk/3749/.
Full textSosa, John Manuel. "Development of Tools for 2D and 3D Microstructural Characterization and Their Application to Titanium Alloy Microstructures." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1420629389.
Full textMoroni, Riko [Verfasser], Lars [Akademischer Betreuer] Pastewka, and Simon [Akademischer Betreuer] Thiele. "Segmentation and computational analysis of 3D porous microstructures in Li-ion cells." Freiburg : Universität, 2020. http://d-nb.info/122783943X/34.
Full textGroeber, Michael Anthony. "Development of an automated characterization-representation framework for the modeling of polycrystalline materials in 3D." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1187104216.
Full textBarry, Erin Patricia. "Three-Dimensional Reconstruction of Microstructures in α + β Titanium Alloys." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1211214635.
Full textMutapcic, Emir, and n/a. "Optimised part programs for excimer laser-ablation micromachining directly from 3D CAD models." Swinburne University of Technology. Faculty of Engineering and Industrial Sciences, 2006. http://adt.lib.swin.edu.au./public/adt-VSWT20061117.154651.
Full textVecchio, Irene [Verfasser], and Claudia [Akademischer Betreuer] Redenbach. "Image based characterization and geometric modeling of 3d materials microstructures / Irene Vecchio. Betreuer: Claudia Redenbach." Kaiserslautern : Technische Universität Kaiserslautern, 2015. http://d-nb.info/1070603740/34.
Full textEichhorn, Melanie [Verfasser]. "3D-microstructures with designed surface chemistry for the study of cell adhesion and deformation / Melanie Eichhorn." München : Verlag Dr. Hut, 2018. http://d-nb.info/1166482510/34.
Full textFlin, Frédéric. "Description physique des métamorphoses de la neige à partir d'images de microstructures 3D naturelles obtenues par microtomographie X." Université Joseph Fourier (Grenoble), 2004. http://www.theses.fr/2004GRE10006.
Full textZerhouni, Othmane. "Etude des propriétés élastiques effectives de matériaux poreux à microstructure aléatoire : Impression 3D, caractérisation, expérimentale et numérique." Thesis, Institut polytechnique de Paris, 2019. http://www.theses.fr/2019IPPAX008.
Full textThis thesis deals with the 3D-printing, numerical simulation and experimental testing of porous materials with random isotropic microstructures. In particular, we attempt to assess by means of well-chosen examples the effect of partial statistical descriptors (i.e., porous volume fraction or porosity, two-point correlation functions and chord-length distribution) upon the linear effective elastic response of random porous materials and propose (nearly) optimal microstructures by direct comparison with available theoretical mathematical bounds. To achieve this, in the first part of this work, we design ab initio porous materials comprising single-size (i.e. monodisperse) and multiple-size (polydisperse) spherical and ellipsoidal non-overlapping voids. The microstructures are generated using a random sequential adsorption (RSA) algorithm that allows to reach very high porosities (e.g. greater than 80%). The created microstructures are then numerically simulated using finite element (FE) and Fast Fourier Tranform (FFT) methods to obtain representative isotropic volume elements in terms of both periodic and kinematic boundary conditions. This then allows for the 3D-printing of the porous microstructures in appropriately designed dog-bone specimens. An experimental setup for uniaxial tension loading conditions is then developed and the 3D-printed porous specimens are tested to retrieve their purely linear elastic properties. This process allows, for the first time experimentally, to show that such polydisperse (multiscale) microstructures can lead to nearly optimal effective elastic properties when compared with the theoretical Hashin-Shtrikman upper bounds for a very large range of porosities spanning values between 0-82%. To understand further the underlying mechanisms that lead to such a nearly optimal response, we assess the influence of several statistical descriptors (such as the one- and two-point correlation functions, the chord-length distribution function) of the microstructure upon the effective elastic properties of the porous material. We first investigate the ability of the two-point correlation function to predict accurately the effective response of random porous materials by choosing two different types of microstructures, which have exactly the same first (i.e., porosity) and second-order statistics. The first type consists of non-overlapping spherical and ellipsoidal pores generated by the RSA process. The second type, which uses the thresholded Gaussian Random Field (GRF) method, is directly reconstructed by matching the one- and two-point correlation functions from the corresponding RSA microstructure. The FFT-simulated effective elastic properties of these two microstructures reveal very significant differences that are in the order of 100% in the computed bulk and shear moduli. This analysis by example directly implies that the two-point statistics can be highly insufficient to predict the effective elastic properties of random porous materials. We seek to rationalize further this observation by introducing controlled connectivity in the original non-overlapping RSA microstructures. The computed effective elastic properties of these microstructures show that the pore connectivity does not change neither the two-point correlation functions nor the chord-length distribution but leads to a significant decrease in the effective elastic properties. In order to quantify better the differences between those three microstructures, we analyze the link between the local geometry of the porous phase and the corresponding computed elastic fields by computing the first (average) and second moments of the elastic strain fluctuations. This last analysis suggests that partial statistical information of the microstructure (without any input from the corresponding elasticity problem) might be highly insufficient even for the qualitative analysis of a porous material and by extension of any random composite material
Moussaoui, Hamza. "Microstructural optimization of Solid Oxide Cells : a coupled stochastic geometrical and electrochemical modeling approach applied to LSCF-CGO electrode." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAI028/document.
Full textThis work aims at better understanding the impact of Solid Oxide Cells (SOC) microstructure on their performance, with an illustration on an LSCF-CGO electrode. A coupled 3D stochastic geometrical and electrochemical modeling approach has been adopted. In this frame, a plurigaussian random field model and an in-house sphere packing algorithm have been adapted to simulate the microstructure of SOCs. The geometrical models have been validated on different electrodes reconstructed by synchrotron X-ray nano-holotomography or focused ion-beam tomography. Afterwards, semi-analytical microstructural correlations have been proposed and validated on a large dataset of representative synthetic microstructures. These relationships allow establishing the link between the electrode ‘basic’ parameters (composition, porosity and grain size), to the ‘key’ electrochemical parameters (Triple Phase Boundary length density and Specific surface areas), and are particularly useful for cell manufacturers who can easily control the first set of parameters. Concerning the electrochemical part, a reference symmetrical cell made of LSCF-CGO has been tested in a three-electrode setup. This enabled the validation of an oxygen electrode model that links the electrode morphological parameters to its polarization resistance, taking into account the thermodynamic data. Finally, the coupling of the validated models has enabled the investigation of the impact of electrode composition, porosity and grain size on the cell electrochemical performance, and thus providing useful insights to cell manufacturers
Li, Jia. "Simulation par éléments finis de la propagation de fissures de fatigue dans les matériaux polycristallins imagés par tomographie aux rayons X." Thesis, Paris, ENMP, 2015. http://www.theses.fr/2015ENMP0079/document.
Full textThe short fatigue crack propagation in polycrystal materials depends strongly on microstructure. Although numerous studies of characterisation and of simulation, the prediction of the short fatigue crack propagation remains a challenge.In order to understand the mechanisms of short fatigue crack propagation, an in-situ characterisation by X-ray tomography was carried out at ESRF, using two techniques of tomography. Diffraction Contrast Tomography (DCT) that is a non-destructive method can be used to obtain 3D morphology and grain orientations in an undeformed state of polycrystal materials. Couple with Phase Contrast Tomography (PCT), it allows to characterise the short fatigue crack propagation at different loading stages. Access to this information, it is possible to simulate the short fatigue crack propagation using a 3D reel microstructural mesh reconstructed from the tomographic images.In this work, the elastic anisotropic behaviour in a 3D microstructural mesh is performed. The elastic strain tensors averaged in grains are also compared to the experimental measurements. Then, a new numerical approach is proposed to simulate crack propagation. From a crystal plasticity FE simulation, the crack growth direction is determined by a post processing. Next, the crack is propagated through remeshing. This approach is firstly applied to the single crystals, then to the polycrystal mesh reconstructed from the tomographic images. The grain boundary effects and the crack growth rate are also analysed. By comparing between simulation and experimental crack, the damage indicator is discussed at the end
Liu, Chao Yuan. "Analyse quantitative des propriétés mécaniques de fraises dentaires rotatives en NiTi et étude de la fabrication de larges microstructures par polymérisation induite à deux photons." Phd thesis, Université de Grenoble, 2014. http://tel.archives-ouvertes.fr/tel-01071805.
Full textLoughnane, Gregory Thomas. "A Framework for Uncertainty Quantification in Microstructural Characterization with Application to Additive Manufacturing of Ti-6Al-4V." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1441064431.
Full textNguyen, Thanh Tung. "Modeling of complex microcracking in cement based materials by combining numerical simulations based on a phase-field method and experimental 3D imaging." Thesis, Paris Est, 2015. http://www.theses.fr/2015PESC1152/document.
Full textAn approach combining numerical simulations and experimental techniques is developed to model complex microcracking in heterogeneous cementitious materials. The proposed numerical model allowed us to predict accurately in 3D the initiation and the propagation of microcracks at the scale of the actual microstructure of a real sample subjected to compression. Its predictions have been validated by a direct comparison with the actual crack network characterized by 3D imaging techniques. In a first part, the numerical simulation tools are developed and tested. More specifically, the phase-field method is applied to microcracking simulations in highly heterogeneous microstructures and its advantages for such simulations are discussed. Then, the technique is extended to account for interfacial cracking, possibly occurring at inclusion/matrix interfaces. In a second part, the experimental methods used and developed in this work are described. The procedures to obtain the evolution of the 3D crack network within the samples by means of X-rays computed microtomography and in-situ mechanical testing are presented. Then, we focus on the developed image processing tools based on digital volume correlation to extract with good accuracy the cracks from the grey level images. In a third part, we compare the predictions of the numerical model with experimental results obtained, first, with a model material made of expanded polystyrene beads embedded in a plaster matrix, and second, to a more complex lightweight concrete. More precisely, we use the experimental data to identify by inverse approaches the local microstructural parameters, and use the experimental displacements measured by digital volume correlation to define boundary conditions to be applied on sub-domains within the sample for the simulations. The obtained direct comparisons of 3D microcrack networks and their evolutions demonstrate the very good predictive capability of the numerical model
Yang, Zhugen. "3D-Microstructured Protein Chip for Cancer Diagnosis." Phd thesis, Ecole Centrale de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00780192.
Full textTusamda, Wakhloo Nayana. "Deformability of cancer cells on 3D microstructured surfaces." Thesis, Mulhouse, 2018. http://www.theses.fr/2018MULH2259.
Full textThis thesis deals with understanding behaviour of different cancer cell types on microstructured topography. We studied the behaviour of osteosarcoma cell line (SaOS-2) on confined micropillar structures and in particular their nuclear deformation. We analysed the role of the cytoskeleton, focal adhesions (FAs), nucleoskeleton (LINC and lamin A) and chromatin in SaOS-2 deformation on micropillar topography. Actomyosin and vimentin intermediate filament were shown to play a crucial role in orchestrating nuclear deformation. We found that FAs arrangement was mostly on side walls of pillars and that the LINC-cytoskeletal connection was essential for the nuclear deformation process but not lamin A. Employing chemo-topography modulations of pillars and a computational simulation model we demonstrated that the pulling down forces and not pushing down forces drive the cellular-nuclear deformation in osteosarcoma cells. We also studied the nuclear deformation of SaOS-2 on hydrogel micropillars with different stiffness and chemistry. We saw that cell morphology, actin organization and FAs behaviour was modulated by the substrate mechanics and chemistry. To explore the role of cancer origin, we examined the behaviour of various colon carcinomas on various micro-topographies and found that the epithelial origin cancers are less responsive to microscale topography compared to mesenchymal origin cancerous cells. However, their behaviour was affected on large pits which resembled the intestinal crypt and villi arrangement in terms of size
Anders, Sebastian [Verfasser]. "Interactions between biosystems and 3D microstructured surfaces / Sebastian Anders." München : Verlag Dr. Hut, 2019. http://d-nb.info/1181514142/34.
Full textCaccuri, Vincenzo. "Etude des propriétés mécaniques de technologies de report de puce pour électronique de puissance : influence du vieillissement." Thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2014. http://www.theses.fr/2014ESMA0002/document.
Full textThe requirement for reducing the use of harmful materials in convenience goods hasprompted investigation into alternative solutions. Along with the need to drastically limit theemission of greenhouse gases, the increase of electric or hybrid vehicles in the market reliesmostly on their dependability with a specific focus on reliability of the embedded powerelectronics. The study of alternative materials to lead (Pb) or Pb-based alloys for die bondingis a critical step towards realising an environmentally friendly solution. Micrometric silverpaste was chosen as a candidate because of its excellent electrical properties. However, fewdata are available in the literature concerning its mechanical properties, mandatory to modelthe entire electronic system for service life assessment. The processing route, based on thesintering of micrometric powder, provides a material with significant porosity that is knownto alter the mechanical properties when compared to the dense material. In this thesis, anoriginal processing route was developed in order to obtain bulk samples with the samemicrostructure of real solder joints either before or after ageing. The mechanical properties vsdensity was established prior to or after aging. After aging, the elastic properties do not varywhile the dispersion observed for the plastic properties is connected with the microstructureevolution. The evolution of the elastic properties on the representative samples of solder jointsafter aging is attributed to the mechanisms of stress relaxation. Once these relaxed, theproperties are identical for both states (bulk and thin layer) and are thus intrinsic in thematerial
Engkvist, Gustav. "Investigation of microstructure and mechanical properties of 3D printed Nylon." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-66304.
Full textMoneghan, Matthew John. "Microstructural Deformation Mechanisms and Optimization of Selectively Laser Melted 316L Steel." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/104170.
Full textMaster of Science
Many researchers have studied the impacts of laser parameters on the bulk material properties of SLM printed parts; few if any have studied how these parts break at a microstructural level. In this work we show how SLM printed parts with complex microstructures including grains, meltpools, and cells, deform and break. The cellular network that occurs in some SLM printed parts leads to a multi-material hierarchical structure, with a stiff network of thin boundaries, and a bulk "matrix" of soft cell material. This leads to similar properties as some composites, whereby the stiff network of cell boundaries leads to increased damage tolerance. We show both computationally through finite element analysis, and experimentally through multi-material 3D fabrication, that the microstructure leads to increased crack length in failure, as well as lower toughness loss and strength loss in the event of a crack. Essentially, the complex nature of the formation of these parts (high heating and cooling rates from laser melting) leads to a beneficial microstructure for damage tolerance that has not been studied from this perspective before.
Alankar, Alankar. "Development of a 3D microstructure sensitive crystal plasticity model for aluminum." Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Dissertations/Spring2010/A_Alankar_020910.pdf.
Full textMa, Lin. "Multi-scale 3D imaging of the microstructure in organic-rich shales." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/multiscale-3d-imaging-of-the-microstructure-in-organicrich-shales(514544f2-39f8-4fe2-b8f4-fecb27380c10).html.
Full textAlshehri, Saad. "Proton beam writing of 3D-microstructure for microfluidics and MEMS applications." Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/809695/.
Full textAlloing-Séguier, Léanie. "Modélisation de la microstructure de l’émail des mammifères : analyses 2D + 3D et approche Évo-Dévo." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20191.
Full textI approached enamel microstructure's morphology and modes of formation with a dual angle, combining paleontological and cellular biology observations, in 2D and 3D. Studying microstructure of extinct and extant Cetartiodactyla in a phylogenetic context, I discovered that some enamel characters are more likely to evolve and change than others, which is linked to different developmental constrains. I also explored microstructure through the relationship between enamel prisms and ameloblasts, the enamel-secreting cells, showing that the arrangement of the cells is directly associated with the prisms'. Then, combining these data, I constructed a model of mammalian enamel microstructure based on 2D and 3D observations and suggested underlying cellular mechanisms, and created a new software dedicated to enamel reconstruction, Simulémail, based on this model. It helped to show that microstructure is not always created the same way for different mammals, and allowed to explore enamel characters efficiently
Marijon, Jean-Baptiste. "Caractérisation 3D de la microstructure et des déformations élastiques des polycristaux par microdiffractiodiffraction Laue." Thesis, Paris, ENSAM, 2017. http://www.theses.fr/2017ENAM0023/document.
Full textThe characterization of the internal stresses present in structural or functional materials is essential for an optimization of their properties and their durability in service. This thesis work is a contribution to the development of the so-called '' Differential Aperture X-ray Microscopy'' (DAXM) technique, allowing 3D and non-destructive characterization of the microstructure of crystalline materials and internal stresses. This technique makes use of synchrotron radiation; we used the beamline CRG BM32 of the European synchrotron ESRF. The polychromatic and highly focused incident beam penetrates the sample, and the collected diffraction image is a superimposition of the Laue diagrams of all the crystals located along the path of the incident beam. The DAXM uses, in addition to the "conventional" Laue microdiffraction technique, a moving mask that absorbs part of the diffracted beams. The analysis of the evolution of the gray levels of the image pixels as a function of the position of the mask makes it possible not only to reconstruct the microstructure of the material at depth but also to access the 3D distribution of the elastic deformations (and associated stress). One of the advantages of the DAXM is its spatial resolution, of the order of a micrometer, which makes it possible to envisage the analysis of stress concentrations in polycrystalline materials, within the framework of experimental micromechanical approaches.The work carried out in this thesis was aimed at improving the existing experimental system,to put in place the theoretical formulation of the problem, and to develop the numerical tools allowing the processing of the data.From an experimental point of view, we have developed an in-situ mechanical test device (4-point bending) adapted to BM32, and we propose a multi-wire mask to significantly reduce the data acquisition time.We have established the geometric equations of the problem. It is thus shown that the 3D reconstruction requires a gray scale derivation procedure. This work is limited to the use of a finite difference derivation method of order 1, which remains sensitive to image noise. These equations show the need to determine the geometry of the setup with great precision. For this purpose, the use of the fluorescence of the sample is proposed, coupled with a simplified description of the beam attenuation by the sample taking into account only a single absorption coefficient. The calibration model is tested on several materials, with very good results.The capacity of the DAXM to reconstruct a microstructure is tested on model samples for which the 3D geometry of the microstructure is perfectly known: a stack of GaN wires on a substrate, and a twin plane in a stainless steel polycrystal. It is shown that the resolution of the DAXM is variable from one pixel to the other of the detector; the microstructure can however be reconstructed with an accuracy of the order of one micrometer.The DAXM is then tested on a sample of UO2 implanted by Kr ions, creating a highly deformed surface layer with micrometric thickness (collaboration with CEA-Cadarache). It is found that the proposed reconstruction method is affected by the variable transmission of the diffracted beams in the mask. We propose a formulation that takes this effect into account
Doherty, Sharon Marie. "Advanced imaging and 3D measurement of microstructure in food emulsions and foams." Thesis, University of Ulster, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.551598.
Full textVelichko, Alexandra. "Quantitative 3D characterization of graphite morphologiesin cast iron using FIB microstructure tomography." Aachen Shaker, 2008. http://d-nb.info/992480035/04.
Full textOudinet, Ghislain. "Analyse d'images et modélisation 2D/3D de la microstructure du combustible MOX." Saint-Etienne, 2003. http://www.theses.fr/2003STET4011.
Full textThe microstructure of the MOX fuel, made with UO2 and PuO2, determines his " in pile " behavior. The french companies CEA and COGEMA are highly interested in its description by image analysis, which is the object of the present work. The segmentation algorithms described here use pictures issued from a microprobe and a SEM, to analyse the plutonium and porosity distribution in the fuel pellets. They are innovating, automated and robust enough to be used with a small data set. They have been successfully tested on different fuels, before and after irradation. Three-dimensional informations have been computed with a genetic algorithm. The obtained 3D object size distributions allowed the modeling of many different industrial and research fuels. 3D reconstruction is accurate and stable, and provides a basis for different studies among which the study of the MOX fuel " in pile " behavior
Matějka, Milan. "Technologie přípravy hlubokých struktur v submikronovém rozlišení." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-256584.
Full textMosaliganti, Kishore Rao. "Microscopy Image Analysis Algorithms for Biological Microstructure Characterization." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1211390127.
Full textLövy, Vít. "Získání 3D informací o struktuře vyvíjeného materiálu Si3N4 pro válcovávání legovaných drátů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231720.
Full textDang, Ning. "3d visualization for microstructure characteristics and damage evolution in dual phase titanium alloy." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI053.
Full textTitanium and its alloys, which have integrated properties including low density, high specific strength and excellent corrosion resistance, are "workhorses" in the field of modern industries. In recent years, with the development of industrial technologies, we have strict requirements on the properties of components made by titanium alloys in severe environment. How to explore further potential properties in titanium alloys? Such question has attracted researchers' eyes. Therefore, in order to reveal the micro-mechanism of damage and fracture for titanium alloys intensively, it is quite necessary to enhance our knowledge on the microstructure characteristics and damage evolution features, particularly on the interplay between microstructure characteristics and voids development. In this thesis, aiming at the variation of microstructure morphologies during damage development, based on X-ray computed tomography (X-ray CT) approach, an integrated methodology containing in situ experiment and CP (Crystal Plasticity) simulation was implemented to focus on the microstructure morphologies and void nucleation / propagation behavior of Ti-6Al-4V (TA6V) alloy during damage evolution. Besides, with the help of realistic microstructure-based RVE (Representative Volume Element) modeling and subsequent deforming simulation, combining with post-mortem by SEM / EBSD, we have revealed the mechanism for damage development by severely analyzing the fracture features. Finally, the correlation between microstructure and evolution is discussed on the basis of simulations and experiments
Asfaw, Habtom Desta. "Multifunctional Carbon Foams by Emulsion Templating : Synthesis, Microstructure, and 3D Li-ion Microbatteries." Doctoral thesis, Uppsala universitet, Strukturkemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-312897.
Full textYang, Xuan. "Three-dimensional Characterization of Inherent and Induced Sand Microstructure." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7557.
Full textDumont, Mikaël. "Composites Carbone/Carbone 3D densifiés par imprégnation/carbonisation de brai mésophasique." Bordeaux 1, 2001. http://www.theses.fr/2001BOR12344.
Full textPeyrega, Charles. "Prédiction des propriétés acoustiques de matériaux fibreux hétérogènes à partir de leur microstructure 3D." Phd thesis, École Nationale Supérieure des Mines de Paris, 2010. http://pastel.archives-ouvertes.fr/pastel-00568918.
Full textHollette, Matthieu. "Modélisation de la propagation des ondes élastiques dans un milieu composite à microstructure 3D." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00840603.
Full textDake, Jules [Verfasser]. "Experimental investigations of microstructural coarsening in 3D using X-ray microscopy / Jules Dake." Ulm : Universität Ulm, 2020. http://d-nb.info/1208296272/34.
Full textKerdja, Youcef. "Caractérisation 3D et modélisation multi-échelle des matériaux actifs de batteries." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALI033.
Full textFour NMC type materials having the same chemical composition (LiNi1/3Mn1/3Co1/3O2) but different microstructures were synthesized and then used as positive electrodes to probe the impact of the microstructure over their electrochemical performances. FIB-SEM tomography was used to get 3D images of the synthesized materials, compute their ionic tortuosity and link the results to the observed electrochemical performances. 2D microscopy images were also obtained on the four materials to go beyond tortuosity computation and realize multi-physics simulations at the microstructure scale on real electrodes. To that end, an electrochemical model at the microstructure level has been developed. This model allows the visualization of the electrochemical kinetics’ as well as lithium liquid and solid diffusion’s influences over the global battery capacity and lithiation heterogeneities at the microstructure level. This study was performed, via a sensitivity analysis of the material physical properties, on a ‘template microstructure’ and allowed us to understand and quantify the different influences’ mechanism and the competition between them over the characteristics of the battery at multiple scales. After that, the developed model was used to simulate galvanostatic discharges on two of the previously extracted 2D microstructures. These simulations allowed us to get a real-time visualization of the local current density as well as of the overpotential at active material-electrolyte interface. The real-time visualization helped us to explain how two NMC type materials having the same chemical composition, but different microstructures led to different discharge capacities
Hwang, Junyeon. "Characterization and Mechanical Properties of Nanoscale Precipitates in Modified Al-Si-Cu Alloys Using Transmission Electron Microscopy and 3D Atom Probe Tomography." Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc3661/.
Full textVelichko, Alexandra [Verfasser]. "Quantitative 3D Characterization of Graphite Morphologies in Cast Iron using FIB Microstructure Tomography / Alexandra Velichko." Aachen : Shaker, 2009. http://d-nb.info/1161310541/34.
Full textDischler, Jean-Michel. "La génération de textures 3D et de textures a microstructure complexe pour la synthese d'images." Université Louis Pasteur (Strasbourg) (1971-2008), 1996. http://www.theses.fr/1996STR13015.
Full textWeiss, Cédric. "Solidification dirigée d'alliages transparents 3D : dynamique de formation de la microstructure interfaciale en présence de convection naturelle." Aix-Marseille 3, 2007. http://www.theses.fr/2007AIX30019.
Full textDirectional solidification of bulk transparent alloys has been studied by optical means with direct observation and interferometry. Some experimental improvements have been done concerning the Bridgman furnace in order to control the interface curvature and also concerning the samples preparation. Interferogram analysis procedures have been developped allowing the characterization of the dendrites (tip radius and tip velocity). The effects of the interface curvature and the convection in the liquid phase have been studied in the cellular and the dendritic regimes. We have observed a cells advection phenomenon affected by the fluid flow in the melt. In dendritic growth, the microstructure is strongly affected by the interface curvature (orientation, shape factor). Finally, a specific device dedicated to the columnar-to-equiaxed transition study has been developped clarifying the role of the dendrites fragmentation in this process
Mirea, Iulia. "Analyse de la microstructure 3D du tissu cardiaque humain à l’aide de la micro-tomographie à rayons X par contraste de phase." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI076/document.
Full textCardiovascular diseases remain one of the most serious health problems, motivating research to deepen our understanding of the myocardial function. To succeed, there is a need to get detailed information about the spatial arrangement of the cardiac tissue components. Currently, our understanding of the cardiac microarcInstitut de Technologie de Harbin - Chineecture is limited by the lack of 3D descriptions of the cardiac tissue at the microscopic scale. This thesis investigates the 3D cardiac tissue microstructure using X-Ray µ-CT phase contrast imaging available at the ESRF. For the first time, 9 human cardiac left ventricle (LV) wall samples are imaged at an isotropic resolution (3.5 µm) and analysed. We focus on the description of the cardiac extracellular matrix (CEM) that is one of the main components of the tissue. The CEM includes: the endomysium that surrounds and separates individual myocytes and capillaries, the perimysium that surrounds groups of myocytes and the epimysium that surrounds the entire heart muscle. Each reconstructed sample is about 30 Gb which represents a large amount of data to process and display. To succeed, we developed an automatic image processing algorithm to binarise each sample by selecting the CEM. We extract statistical features of the ECM, mainly the thickness of the cleavage planes (CP) and the inter-CP distances. The results show that the local 3D arrangement of the CP differs according to their location in the LV (posterior, anterior, septal) and their distance from the apex (more complex). The thickness of the CP extracted from all the samples roughly ranges from 24 µm to 59 µm and the inter-CP distances from 70 µm to 280 µm with significant local variations of the standard deviation. Those new quantitative markers of the ECM of the human cardiac are of main interest for a better understanding of the heart function
Serre, Benoit. "Simulation numérique 3D de la croissance de grains par la méthode des éléments finis." Saint-Etienne, EMSE, 2008. http://www.theses.fr/2008EMSE0005.
Full textPhysical properties of material are influenced by microstructure. The main objective of this thesis is a software creation for simulation of microstructure evolution. A finite element approximation based on grain growth model is used. A variable number of degrees of freedom is applied for each node to take into account normal grain growth hypothesis and to reduce the number of degrees of freedom of problem. A dedicated tools for remeshing is used to follow large evolution of microstructures. A single algorithm is able to treated all topological transformations with or without periodic condition. All these tools are used to simulate microstructure evolution with several decades of grains
Yeddu, Hemantha Kumar. "Martensitic Transformations in Steels : A 3D Phase-field Study." Doctoral thesis, KTH, Metallografi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-95316.
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Simsir, Caner. "3d Finite Element Simulation Of Steel Quenching In Order To Determine The Microstructure And Residual Stresses." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609412/index.pdf.
Full textby user subroutines. The accuracy of the model was verified by simulating the quenching of eccentrically drilled steel cylinders. Simulation results were justified via SEM observations and XRD residual stress measurements. According to the results, the model can effectively predict the trends in the distribution of microstructure and residual stresses with a remarkable accuracy.
Amsellem, Olivier. "Simulations 2D et 3D de microstructure d'alumine projetée plasma pour l'étude de ses propriétés mécaniques et électriques." Phd thesis, École Nationale Supérieure des Mines de Paris, 2008. http://tel.archives-ouvertes.fr/tel-00331802.
Full textPICO, RUBY LORENA HERNANDEZ. "INFLUENCE OF MICROSTRUCTURE ON MECHANICAL PROPERTIES OF CARBONATE ROCKS USING 3D DIGITAL IMAGES OF X-RAY MICROTOMOGRAPHY." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2013. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=23966@1.
Full textCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
Reservatórios carbonáticos contêm entre 50 e 60 por cento de petróleo e gás do mundo. No entanto, estas rochas têm apresentado problemas operacionais consideráveis durante as etapas de perfuração e produção. Tais problemas são originados pelas dificuldades na caracterização adequada destas rochas em função da complexa distribuição espacial de sua micro e macro estrutura. Enquanto ambas as escalas possuem importância no entendimento do comportamento de carbonatos, o presente trabalho trata da análise da microestrutura. Nesse âmbito, a proposta deste trabalho integra o processamento e análises de imagens digitais adquiridas mediante microtomografia de raios-X, elaboração de malhas de elementos finitos e simulação numérica de forma a prever propriedades elásticas, com o objetivo de correlacionar a microestrutura e o módulo de Young. Foram utilizadas imagens digitais de amostras de afloramento (travertinos) considerados como possíveis análogas a rochas carbonáticas de reservatório. A metodologia implementada permitiu obter sub-amostras que incluem uma gama de microestruturas e porosidades numa única amostra para assim simular numericamente o módulo de Young. Os resultados dos ensaios virtuais foram comparados com os resultados de ensaios reais executados em amostras da mesma rocha e dados encontrados na literatura. A aplicação da metodologia e os resultados obtidos indicam o potencial e as limitações atuais desta técnica. Conclui-se neste estudo que o valor do módulo de Young das amostras simuladas numericamente é afetado pela distribuição espacial, conectividade dos poros e pela microporosidade da rocha. Os valores encontrados no ensaio virtual tendem a serem superiores aos obtidos em ensaios reais devido à dificuldade de inserir, no modelo de micro estrutura, os contatos entre os grãos assim como regiões mais compressíveis não determinadas na aquisição das imagens.
Carbonate reservoirs contain between 50 and 60 per cent of oil and gas in the world. However, these rocks have presented considerable operational problems during drilling and production steps. Such problems are caused by the difficulties in proper characterization of these rocks due the complex spatial distribution of their micro and macrostructure. Although both scales have importance in understanding the behavior of carbonates, the present work deals with the analysis of the microstructure. In this context, the proposal of this work integrates the processing and analysis of digital images acquired by x-ray microtomography, finite element mesh generation and numerical simulations to predict elastic properties in order to correlate the microstructure and the Young s modulus. We used digital images of samples of outcrop (travertine) considered as a possible analogous to carbonate rocks of reservoir. The methodology implemented allowed get sub-samples that include a range of microstructures and porosities in a single sample to determine numerically the Young s modulus. The virtual test results were compared with laboratory test results performed on samples from the same rock and data found in the literature. The application of the methodology and the results obtained indicate the potential and current limitations of this technique. This study concluded that the value of Young s modulus of numerically simulated samples is affected by spatial distribution, pore connectivity and microporosity of these rocks. The values found in the virtual test tend to be higher than those obtained in laboratory tests due to the difficulty of inserting, in the model of micro structure, contacts between the grains as well as more compressible regions not certain on the acquisition of the images.