Дисертації з теми "3D woven organic composites"
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Orenes, Balaciart Salvador. "In Situ Characterization by Acoustic Emission and X-Ray μ-Computed-Tomography of the Effects of Temperature, Aging, and Multi-Axial Loads on Damage Onset in 3D Woven Organic Matrix Composites for Aeronautical Applications". Electronic Thesis or Diss., Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2024. http://www.theses.fr/2024ESMA0010.
Повний текст джерелаThe field of aeronautical engineering has seen considerable advancements over the past decades in materials science. Carbon fibre Three-Dimensional Woven Organic Matrix composites (3DOMC) are increasingly used as elements of structural parts close to aircraft engines and in aero-engine fan blades. These materials are therefore requested to operate in high-performance ranges subjected to multi-axial mechanical solicitations at different temperatures and exposed to cold/hot thermal cycling. Although there is substantial literature on the effects of such solicitations on the fracture behavior and ultimate damage mechanisms of 3DOMC, there is a limited study on the initial damage mechanisms. This gap is particularly critical since the onset of damage dictates the usability of such components; from operational standpoint, no damage is permissible in service in these parts. This work aims to develop a novel experimental methodology to characterize the onset of damage in 3DOMC for different multi-axial solicitations encountered in-service.To achieve this, an in situ test has been designed coupling μ-Computed Tomography (μ-CT) and Acoustic Emission (AE), successfully identifying multi-axial damage initiation during tensile test and Eccentric Compression Bending (ECB) in in-axis and off-axis specimens. The effect of temperature has been addressed via in situ test implementing the new developed methodology test at high (120ºC) and low (-30ºC) temperature; it has been found damage initiation mechanisms are strongly dependent on temperature.The effect of thermal cycling between 120ºC and -55ºC on damage onset has been characterized by AE and ex situ (μ-CT). Further, damage propagation up to 1000 cycles has been characterized in detail in the 3D woven meso-structure. Finally, thermal cycling degradation and ageing on damage onset is investigated in static in situ tensile test
Stig, Fredrik. "3D-woven Reinforcement in Composites." Doctoral thesis, KTH, Lättkonstruktioner, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-70438.
Повний текст джерелаQC 20120131
El, Said Bassam Sabry Fawzy. "Integrated multi-scale modelling of 3D woven composites." Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.720811.
Повний текст джерелаKing, Robert Scott. "Damage tolerant 3D woven technical textiles in reinforced composites." Thesis, University of Ulster, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516537.
Повний текст джерелаDai, Shuo. "Mechanical characterisation and numerical modelling of 3D woven composites." Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/16221.
Повний текст джерелаArshad, Mubeen. "Damage tolerance of 3D woven composites with weft binders." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/damage-tolerance-of-3d-woven-composites-with-weft-binders(2b1435bc-fdb7-47c3-b555-ca5ea2883b4b).html.
Повний текст джерелаGreen, Steven Daniel. "Modelling preform consolidation and its effects in 3D woven composites." Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.705451.
Повний текст джерелаStig, Fredrik. "An Introduction to the Mechanics of 3D-Woven Fibre Reinforced Composites." Licentiate thesis, Stockholm : Skolan för teknikvetenskap, Kungliga Tekniska högskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10235.
Повний текст джерелаManjunath, R. N. "Design and development of 3D woven complex hollow structures and their composites for energy absorbent structures." Thesis, IIT Delhi, 2019. http://eprint.iitd.ac.in:80//handle/2074/8059.
Повний текст джерелаBroderick, John. "Advancement of 3D woven composites through embedded in situ strain measurement." Thesis, University of Ulster, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546738.
Повний текст джерелаPoole, Matthew C. "Fatigue damage development in 3D woven glass and glass/carbon composites." Thesis, University of Surrey, 2018. http://epubs.surrey.ac.uk/845964/.
Повний текст джерелаWaterton, Taylor Lindsey. "Design and manufacture of 3D nodal structures for advanced textile composites." Thesis, University of Manchester, 2007. http://www.manchester.ac.uk/escholar/uk-ac-man-scw:151244.
Повний текст джерелаFergusson, Alexander D. "Evaluating the mechanical behaviour of orthotropic 3D woven carbon fibre reinforced composites." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/6146.
Повний текст джерелаBuchanan, Saul. "Models to Predict the Geometric and Elastic Stiffness Properties of 3D Woven Composites." Thesis, University of Ulster, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515431.
Повний текст джерелаTurner, Paul. "Deformation and collapse of orthogonal 3D woven composites : quasi-static and impact loading." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/32732/.
Повний текст джерелаKong, Weiyi. "Macro-scale modelling of the impact response of 3D woven composites for aerospace applications." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/35756/.
Повний текст джерелаRudov-Clark, Shoshanna Danielle, and srudov-clark@phmtechnology com. "Experimental Investigation of the Tensile Properties and Failure Mechanisms of Three-Dimensional Woven Composites." RMIT University. AEROSPACE, MECHANICAL AND MANUFACTURING ENGINEERING, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080808.115853.
Повний текст джерелаBadawi, Said Sobhey. "Development of the Weaving Machine and 3D Woven Spacer Fabric Structures for Lightweight Composites Materials." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1195729741274-93895.
Повний текст джерелаDie Ziele der Arbeit bestanden in der Entwicklung der Geometrie der Spacer Fabrics und der notwendigen Falteneinrichtung an der Bandwebmaschine. Spacer Fabrics werden ausschließlich aus zwei Deckflächen, die durch eingewebte Stege verbunden sind, gefertigt. Zur Entwicklung der Spacer Fabrics muss eine Doppelnadel-Bandwebmaschine mit zwei Webfächern eingesetzt werden. Für die Faltenwebeinrichtung werden der entwickelte Extra-Kettablass und der Extra-Abzug benötigt. Der Antrieb und die Steuerung des Extra-Abzuges erfolgen durch einen Synchronantrieb und der Antrieb und die Steuerung des Extra-Ablasses durch Pneumatik.Eine frei programmierbare Steuerung der Faltenwebeinrichtung ermöglicht eine sichere und optimierte Synchronisation zwischen Webprozess und Faltenbildung. Im Ergebnis einer systematischen Strukturentwicklung von Spacer Fabrics und der Simulation ihrer günstigen Herstellung mittles eines speziell entwickelten Slippage Strength Tests werden die optimalen Strukturen ermittelt. Die experimentellen Untersuchungen bringen grundlegende Erkenntnisse für die folgenden Forschungsschritte zur Entwicklung von gewebten Spacer Fabrics mit Hochleistungsgarnen auf Doppelgreiferwebmaschinen
Adluru, Hari Kishore. "A Novel Hip Implant Using 3D Woven Composite Material – Design and Analysis." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2318.
Повний текст джерелаYu, Bo. "Damage characterisation of 3D woven glass-fibre reinforced composites under fatigue loading using X-ray computed tomography." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/damage-characterisation-of-3d-woven-glassfibrereinforced-composites-under-fatigue-loading-using-xraycomputed-tomography(e4d6ee91-e3f5-4b33-b9e7-4367cbbfcf0c).html.
Повний текст джерелаKearns, Eleanor Rose. "Multi-stimuli Metal-organic frameworks and their composites." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29561.
Повний текст джерелаPanchal, Dhaval. "Failure and damage progression of 3D woven composite structures subjected to out-of-plane loading." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/33284.
Повний текст джерелаGuigon, Camille. "Vieillissement par cyclage thermique de composites interlocks 3D à matrice polymère." Thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2015. http://www.theses.fr/2015ESMA0004.
Повний текст джерелаThe introduction of composite materials in critical structural parts for aircrafts represents a real technological breakthrough and requires specific studies to understand their behavior and durability. This work aims to characterize and understand the ageing mechanisms incarbon/epoxy 3D interlock composites when they are submitted to thermal cycling.For this purpose, a thermal cycle test (-55°C/120°C), whose heat and gaseous environment istotally mastered, was set up for the ageing of composite samples of elemental interlock pattern dimensions. Analysis of induced degradation mechanisms was achieved by i/ the development ofa 3D quantitative characterization method of the evolution of microcracks during cycling, basedon observations by microtomography RX and the development of a specific image processing procedure, ii/ the development of an in situ thermal cycle test under synchrotron light, coupled to a digital volume correlation technique, and iii/finite elements simulations taking into account the actual mesoscopic architecture of the samples and the thermo-viscoelastic behavior of thematrix.The results reveal complex thermo-chemo-mechanical couplings that are linked to four important parameters: time (and the number of cycles), the interlock architecture, the matrix toughness andits sensitivity to thermo-oxidation
Roirand, Quentin. "Modélisation multiéchelle du comportement et de l'endommagement de composites tissés 3D. Développement d'outils numériques d'aide à la conception des structures tissées." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM036/document.
Повний текст джерелаWith their large flexibility of design , 3D woven composites can provide mechanical properties tailored specificially to structural needs. However, the architectural complexity of woven reinforcements presents serious challenges when predicting properties, behaviours and damage processes. The present work deals with these challenges and seeks to develop numerical tools which are able to foresee the mechanical characteristics of this kind of materials. For this purpose, a multiscale approach, which combines experimental tests and numerical simulations, has been adopted. This approach allows, simultaneously, to take into account the loads and composite behavior, at the macroscopic scale, also the reinforcement geometry and the material heterogeneities which are only visible at the mesoscopic scale. The experimental investigation has been carried out to characterize the behaviour of an 2.5D interlock composite and its constituents. Examinations of the damage mechanisms have also been performed, using tomography and the interzone concept, for this woven composite under loadings in tension and combined tension and bending. With regards to the numerical modeling part, the ultimate degradation of the composite was simulated by cutting the reinforcement yarns with a failure criterion, previously reported, on a 3D representative cell of the experimental composite. For the two kinds of macroscopic loadings, the locations, orientations and kinetics of the damage were found to be fully in agreement with the experimental results. The influence of the architectural parameters on the failure criterion was then evaluated by finite element calculation. Consequently, it has been possible to proposed optimized architectures and make a camparison, for the two macroscopic loadings, with the 2.5D interlock woven composite. Still motivated to improve the prediction of the behaviour of woven composites, this work has also been on developing a finer modeling approach to the understanding of damage mechanisms. A stochastic approach was therefore introduced to the failure criterion using a Weibull statistical distribution. In addition, matrix cavitation has also been taken into account in the modelling. This damage mechanism was simulated using the GTN (Gurson-Tvergaard-Needleman) model. Finally, model reduction techniques have been applied to lower the cost of computing multiscale modeling in order to identify, for example, material properties by an inverse method or to simulate fatigue tests
Médeau, Victor. "Rupture des composites tissés 3D : de la caractérisation expérimentale à la simulation robuste des effets d’échelle." Thesis, Toulouse, ISAE, 2019. http://www.theses.fr/2019ESAE0025/document.
Повний текст джерелаThis work aims to describe and quantify the failure mechanisms of 3D woven composites underquasi-static tensile loading and to implement an adapted and robust numerical simulationmethod, that can be applied in industry. To this end, an experimental study was carried out toquantify the propagation of cracks in these materials. Thus, a crack propagation scenario wasestablished, thanks to the multi-instrumentation used during the tests. The experimental campaignwas carried out on specimens of various geometries and sizes and highlighted significantvariations in the fracture toughness with the test conditions. A modelisation framework introducinginternal lengths was then presented and adapted to 3D woven composites. This frameworkis supported by the identification of the failure mechanisms subsequent to the analysis of thecrack profile. The introduced lengths were thus related to the weaving parameters. A method foridentifying the parameters was proposed and the consequences of this behaviour on the designof the composite parts discussed. Finally, these results were transferred to robust numerical simulations.Regularisation methods of continuous damage models were presented and evaluatedin terms of their ability to ensure, on the one hand, the robustness of the results and, on theother hand, the correct transcription of experimental size effects. Taking into account these numericaland physical considerations led us to propose a Non-Local damage model. A method foridentifying the parameters and the internal length on experimental data was proposed
Angrand, Lise. "Modèle d’endommagement incrémental en temps pour la prévision de la durée de vie des composites tissés 3D en fatigue cyclique et en fatigue aléatoire." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLN005/document.
Повний текст джерелаThe work presented in this report is part of the Collaborative Research Project PRC Composites, funded by the DGAC involving Safran, Onera and several CNRS laboratories whose LMT Cachan. One of the main objectives of this project PRC is to establish models capable to simulate the mechanical behavior, durability and still manufacturing processes for composite PMC. This thesis focus on the study of the behavior of 3D woven composite to mechanical fatigue stresses. This thesis further to the work developed at Onera on cycle damage models for fatigue on PMC, named ODM-PMC. We propose a kinetic damage model, which calculates the kinetic damage evolution, over time. This model is then able to take into account the cycle fatigue loads, and on the other hand the complex or random fatigue loads. The proposed kinetic damage law involves two damage contributions, a monotonous contribution for static loads and a fatigue contribution for fatigue loads. The monotonous contribution is fully equivalent to the monotonous law of ODM-PMC model, the parameters are easily identifiable. The fatigue contribution is not equivalent to the fatigue damage law of initial model ODM-PMC, this is explained by the fact that there are different ways to take into account the average stress effect, unavoidable concept for the study of fatigue loads. We have chosen to consider the mean stress effect by adding the calculation of a mean that evolves during the loading. The identification of fatigue parameters takes place in two steps. The first step is based on a simplification of the model equation set (elasticity and damage are not coupled) to determine a simple relationship, 1D, between the number of cycles to failure and the maximum stress. This expression allows us then quickly to draw diagrams Wohler (σ_a ou σ_Max vs N_R) as well as Haigh diagram (σ_a vs σ ̅). These diagrams allow us to make an initial identification of fatigue parameters. The second step is to readjust certain parameters using the full model 3D, numerical, the 3D model was been encoded for both strain and stress steering. Nevertheless, the methodology requires having a lot of experimental results. It allows also to identifying fatigue parameters at other temperatures in order to provide isothermal modeling. The damage model is made with a first probabilistic approach, pragmatic, to the great number of cycles fatigue. One parameter (determinist), is defined as a random variable, it is the fatigue damage threshold (strain) delimiting the endurance unlimited domain
Garcia, Cécile. "Modélisation de l'endommagement et de la rupture des matériaux composites tissés 3D appliquée aux chapes ceinturées." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLN035.
Повний текст джерелаThe challenge of this work is to offer tools to the Safran design office for the sizing of lugs made of organic matrix 3D woven composite material. Shear failure is the predominant failure mode on 3D woven composite lugs due to their geometry and the lack of 45° reinforcements. Thus, in this work, special attention is paid to this failure mode. An experimental characterization of the shear failure is carried out, showing matrix cracks along the shear strips. The ODM-CMO model, already validated for bearing and net tensile failure modes, is here enriched to properly describe the shear failure damage scenario. More precisely, the matrix damage evolution law is modified for high shear levels. The model is validated through comparisons with test results available on lugs.Subsequently, an innovative solution of lug is examined, based on the belting of the part. The objective of this design of lug is to provide reinforcements to avoid the shear failure mode that occurs prematurely. This concept induces complex three-dimensional stress states, and particularly off-plane components of the stress tensor. As off-plane material parameters are difficult to identify, an identification method based on full-field measurement is proposed, implemented and applied to the material of interest using elementary tests. An original technological set-up to test the belt in tension with appropriate instrumentation is proposed on the basis of simulations. Three tests have been performed. The belts failed in net tension, reflecting an increase in performance over the monolithic 3D woven composite lug studied in first part
Navrátil, Libor. "Apports de l'imagerie qualitative infrarouge pour la caractérisation thermomécanique et le dimensionnement en fatigue de composites tissés 3D." Thesis, Brest, École nationale supérieure de techniques avancées Bretagne, 2021. http://www.theses.fr/2021ENTA0007.
Повний текст джерелаThis work focuses on the thermomecanical characterisation and design against fatigue of a woven composite that is produced for research purposes by the Safran Group. The experimental characterisation is based mainly on the analyses of infrared measurements. The experimental protocols, used for generating the experimental database, are based on the heat build-up protocol, which seeks to relate the temperature variations measured under cyclic loadings to different heat sources. In order to fully exploit the experimental data, different postprocessing tools that enable to highlight mechanisms characteristic to woven composites were developed (thermal event detection, frequency analyses, ...). This experimental characterisation is then complemented by results coming from simulation/experiment comparisons. The latter enable to identify dissipative mechanisms activated under relatively low cyclic loadings. Furthermore, this dissipative mechanism description was used to introduce a rapid fatigue characterisation method that identifies an S-N curve model based on the results of tensile tests and heat build-up experiments
Foti, Federico. "Effect of the Environment on the Fatigue Behaviour of Textile Organic Matrix Composite Materials for Aircraft Applications." Thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2017. http://www.theses.fr/2017ESMA0031/document.
Повний текст джерелаIn the next future, the employment of organic matrix/carbon fibre composites (OMC) is foreseen for the realization of “hot” structures: these parts may be subjected, in service, to mechanical fatigue (e.g. fan blades turbo-engines), thermal cycling and thermo-mechanical fatigue (e.g. aircraft structural parts). Though there is a consistent literature concerning the fatigue behaviour of woven composites, the interaction between fatigue and environmental degradation at high temperature has been poorly explored. Coupling between thermo-oxidation effects, mechanical (viscoelastic, viscoplastic) behaviour of the polymer matrix at high temperatures and degradation due to fatigue may be highly detrimental for the material. This work aims at characterizing and modelling - for carbon fibre/organic matrix (polyimide) textile composites – the thermomechanical behaviour, the onset and the development of damage related to cyclic mechanical mechanisms (fatigue) under controlled (temperature and gas) environment.A preliminary study on a cross-ply laminate [02/902]s has been carried out in order to analyse the environmental effect on a model sample. Digital Image Correlation (DIC) and μ-Computed Tomography (μCT) have been used to monitor and characterize the fatigue damage of 2D woven composites for aeronautical applications. The environmental effect on fatigue degradation have been also explored.The long-term aim of the study is to provide experimental and numerical tools to strengthen the understanding and the modelling of mechanics/damage/environment coupling for durability prediction
Hollette, 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.
Повний текст джерелаEmbrey, Leslie. "Three-Dimensional Graphene Foam Reinforced Epoxy Composites." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3128.
Повний текст джерелаHussain, Muzzamal. "Couplage procédé / propriétés mécaniques des matériaux sandwiches Métal / Composite hybride à base de tissus en jute." Thesis, Lille, 2021. http://www.theses.fr/2021LILUI006.
Повний текст джерелаIn current study the mechanical properties of 3D woven jute reinforced and hybrid 3D woven jute reinforced FMLs were investigated. The four-layered 3D woven reinforcement was made with jute yarn using four types of interlocking patterns e.g. Orthogonal Through Thickness OTT and Orthogonal Layer to Layer OLL interlocking. The vacuum infusion technique was used for the fabrication of FMLs made with 3D woven jute reinforcement. After the optimization of 3D woven reinforcement the hybrid reinforced FMLs were developed in which OTT 3D woven fabric was sandwiched between 2D woven skin. Four different kinds of fibres were used to make 2D woven skin e.g. jute, aramid, carbon, and glass while three different kinds of matrix were employed, e.g. epoxy, PVB and PP. The compression hot press was used to develop hybrid reinforced FMLs. Aluminium used to make all FMLs was anodized before using for fabrication. The adhesive properties were investigated to check the quality of surface treatment, metal-composites bonding and effect of fibres and matrix. Both monotonic and dynamic properties were also investigated. The adhesive properties were characterized using t-peel and floating roller peel tests. The monotonic properties were analyzed using tensile and flexural tests. The low velocity impact performance was determined using drop weight low velocity impact test. The results showed that the anodized aluminium surface had high surface free energy so the better wetting of aluminium can be achieved by anodizing as compared to other type of surface preparations. The adhesive bonding analysis results showed that the delamination properties were mainly influenced by the nature of adhesive material rather than the type of structures of reinforcement. The nature of the matrix also influences the type of failure as with the epoxy the dominant failure was cohesive while with thermoplastic matrix it changed to adhesive and intra-laminar failure. The plasticity and ductility of matrix influenced the final properties more than the type of failure, in spite of cohesive failure of epoxy the thermoplastic matrix had more delamination force. The tensile and flexural properties of OTT 3D woven jute reinforced FMLs were higher than the OLL 3D woven reinforced FMLs due to the higher metal volume fraction, this was possible due to tighter construction of OTT fabric. The tensile and flexural properties of hybrid reinforced composites and FMLs were influenced by the type of matrix and material of 2D skin. The overall higher properties were achieved with an epoxy matrix followed by PVB matrix. The PVB-based FMLs showed that their properties were comparable with the epoxy. The flexural test showed that hybrid FMLs based on PP were failed prematurely due to delamination between synthetic skin and 3D woven core. Both epoxy and PVB showed better impregnation of the reinforcement unlike PP in which only mechanical interlocking was seen. The dynamic impact properties of hybrid composites and FMLs showed that the energy dissipation characteristics were influenced by matrix and hybridization of reinforcement
Vilfayeau, Jérôme. "Modélisation numérique du procédé de tissage des renforts fibreux pour matériaux composites." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0026/document.
Повний текст джерелаThe aeronautical industry faces new challenges regarding the reduction of fossil fuel consumption. One way to address this issue is to use lighter composite materials. The ability to predict the geometry and the mechanical properties of the unit cell is necessary in order to develop 3D reinforcements in composite materials for these aeronautical applications. There is a difficulty to get realistic geometries for these unit cells due to the complexity of their architecture. Currently, existing tools which model 3D fabrics at a meso scale don't take into account manufacturing process influence on the shape modification of the textile structure. There is already some numerical tools that can model the braiding or knitting process, but none have been developed for weaving so far. Consequently, this study deals with the numerical simulation of the weaving process to obtain a deformed dry fabric structure. During the weaving process of E-glass fabrics, achieved in our laboratory, it has been observed that large deformations led to the modification of transverse section of meshes, or local density changes, that can modify the fabrics mechanical resistance. For this reason, a numerical tool of the weaving process, based on finite element modelling, has been developped to predict these major deformations and their influences on the final textile structure. The correlation between numerical results and fabrics produced with glass fibres has been achieved for plain weave and 2-2 twill
Wendling-Hivet, Audrey. "Simulation à l'échelle mésoscopique de la mise en forme de renforts de composites tissés." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0079.
Повний текст джерелаNowadays, manufacturers, especially in transport, are increasingly interested in integrating composite parts into their products. These materials have, indeed, many benefits, among which allowing parts mass reduction when properly operated. In order to manufacture these parts, several methods can be used, including the RTM (Resin Transfer Molding) process which consists in forming a dry reinforcement (preform) before a resin being injected. This study deals with the first stage of the RTM process, which is the preforming step. It aims to implement an efficient strategy leading to the finite element simulation of fibrous reinforcements at mesoscopic scale. At this scale, the fibrous reinforcement is modeled by an interlacement of yarns assumed to be homogeneous and continuous. Several steps are then necessary and therefore considered here to achieve this goal. The first consists in creating a 3D geometrical model of unit cells as realistic as possible. It is achieved through the implementation of an iterative strategy based on two main properties. On the one hand, consistency, which ensures a good description of the contact between the yarns, that is to say, the model does not contain spurious spaces or interpenetrations at the contact area. On the other hand, the variation of the yarn section shape along its trajectory that enables to stick as much as possible to the evolutive shape of the yarn inside the reinforcement. Using this tool and a woven architecture freely implementable by the user, a model representative of any type of reinforcement (2D, interlock) can be obtained. The second step consists in creating a 3D consistent hexahedral mesh of these unit cells. Based on the geometrical model obtained in the first step, the meshing tool enables to mesh any type of yarn, whatever its trajectory or section shape. The third step consists in establishing a constitutive equation of the homogeneous material equivalent to a fibrous material from the mechanical behavior of the constituent material of fibers and the structure of the yarn. Based on recent experimental and numerical developments in the mechanical behavior of fibrous structures, a new constitutive law is presented and implemented. Finally, a study of the different parameters involved in the dynamic/explicit scheme is performed. These last two points allow both to a quick convergence of the calculations and approach the reality of the deformation of reinforcements. The entire chain modeling/simulation of fibrous reinforcements at mesoscopic scale created is validated by numerical and experimental comparison tests of reinforcements under simple loadings
Alia, Adem. "Comportement à la rupture d'un composite à fibres végétales." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI016.
Повний текст джерелаThe objective of this thesis is the characterization of the mechanical behavior and the damage of a woven jute / polyester composite. natural fibers are indeed an interesting ecological alternative to synthetic fibers, in particular glass fibers which are the most used for composite manufacturing. The studied composite is developed in the LMNM laboratory at IOMP, Sétif, Algeria. Two fibre orientations ([0] 8 and [+ 45 / -45] 2S) are considered. The mechanical characterization is carried out in monotonic tensile and compression as well as in cyclic fatigue. Mechanical and microstructural characterizations are carried out in the MATEIS laboratory. The study of the damage is carried out by combining five techniques: the evolution of mechanical parameters via cyclic and fatigue tests, microscopy, acoustic emission (EA), image correlation and micro- RX tomography. The study of the evolution of the mechanical parameters combined with the global analysis of the AE provides first indicators concerning the development of the damage during the tests. Microstructural analyzes allow to finely identify the damage mechanisms that occur during mechanical tests (fiber / matrix decohesions, matrix cracks and fiber breakage). For the segmentation of acoustic emission signals in monotonic tests, an unsupervised classification is used, emphasizing the choice of descriptors and the labeling of the classes obtained. Tensile tests instrumented by image correlation as well as in situ tensile tests under tomography allow to identify the chronology of appearance of the damage. These results are also used to label the obtained classes . The labeled signals are then used to create a library to identify the chronology of evolution of the modes of damage in cyclic fatigue achieved by supervised classification. Finally, all these analyzes made it possible to establish damage scenarios for the different damage modes and for the two orientations. It is thus possible to reconsider the development to optimize the mechanical properties
Naouar, Naïm. "Analyse mésoscopique par éléments finis de la déformation de renforts fibreux 2D et 3D à partir de microtomographies X." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0088/document.
Повний текст джерелаThe simulation at meso-scale of textile composite reinforcement deformation provides important information. In particular, it gives the direction and density of the fibres that condition the permeability of the textile reinforcement and the mechanical properties of the final composite. These meso FE analyses are highly dependent on the quality of the initial geometry of the model. Some software have been developed to describe composite reinforcement geometries. The obtained geometries imply simplification that can disrupt the reinforcement deformation computation. The present work presents a direct method using computed microtomography to determine finite element models based on the real geometry of the textile reinforcement. The FE model is obtained for any specificity or variability of the textile reinforcement, more or less complex. The yarns interpenetration problems are avoided. These models are used with two constitutive laws : a hypoelastic law and a hyperelastic one. An analysis of their properties is presented and their implementation in the software ABAQUS is detailed. Finally, an identification method is presented and the results of forming simulations are compared to experimental tests, which shows a good fit between the both
Bai, Renzi. "Modélisation de la mise en forme des renforts fibreux : Nouvelle Approche de coque spécifique et étude expérimentale." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI108.
Повний текст джерелаThe deformation of textile composite reinforcements is strongly conditioned by their fibrous composition. Classic plate and shell theories are based on kinematic assumptions that are not verified for textile reinforcements. Experiments show that the slippage between fiber (layer) in the thickness makes the specificity of fibrous materials. The RTM process (one of the forming process) is widely used to obtain composite parts with complex geometry is with great importance. In order to optimize the manufacturing of product, numerical models are necessary. Therefore, a 3D shell approach specific to fiber reinforcements is proposed which is based on two specificities: the quasi-inextensibility of the fibers and the possible sliding between the fibers. This approach is developed in the frame of continuum-based shell, the new assumption who based on the conservation of the thickness is applied to the kinematic equation. The theory of virtual power reflects the specific deformation of the fibrous reinforcements. It considers the tensile and bending stiffness of the fibers and the in-plan shear stiffness. The friction between fibers is taken into account in a simple way in connection with bending. The present approach is based on the real physics of the deformation of textile reinforcements. It simulates the 3D deformations of textile reinforcements and provides displacements and deformations for all the points along the thickness of the fabric and simulates the correct rotations of the material director. Finally, experiments and simulations performed on multilayer reinforcements are presented in this work, and a new method of experimentation is proposed
Wendling, Audrey. "Simulation à l'échelle mésoscopique de la mise en forme de renforts de composites tissés." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00961196.
Повний текст джерелаZhang, Chuyang. "Characterization and modeling of 3D woven composites." 2003. http://www.lib.ncsu.edu/theses/available/etd-06112003-210833/unrestricted/etd.pdf.
Повний текст джерелаDash, Bibhu Prasad. "Modelling and characterization of 3D woven solid structures and their composites." Thesis, 2013. http://localhost:8080/xmlui/handle/12345678/6511.
Повний текст джерелаNeje, Ghanshyam Suryakant. "Design and development of 3d woven spacer fabrics for structural composites." Thesis, 2018. http://eprint.iitd.ac.in:80//handle/2074/7988.
Повний текст джерела陳昆泓. "The Fatigue Behavior of Connected Structures Made with 3D I-Shape Woven Composites." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/01811643126683450112.
Повний текст джерела逢甲大學
紡織工程學系
87
The purpose of this investigation is to study the fatigue behavior of connected structures made with 3D I-shape woven composites. Three different I-shape woven preforms, type I, type II, and type III were used in this work. Two aluminum blocks were bonded to a I-shape composite structures to form a connected rectangular beam. The four-point bending tests under both static loading and cyclic loading were carried out using the Material Testing System (MTS-810). The curves of residual strength versus loading cycles were constructed for those three type composite structures to investigate the variation of fatigue residual strength over cycle numbers. The S/N curves were also drawn to discuss the effect of layer number on the fatigue strength and fatigue sensitivity. From experimental results, typeI was found to have higher strength than type II and type III in both static loading and cyclic loading. The fatigue limit strength of typeI and III were calculated to be respectively 64﹪and 56﹪of their ultimate flexural strength. The residual strength decreased slowly with loading cycles throughout most parts of fatigue life. As approaching final fatigue failure, the residual strength decreased abruptly. The metallographic microscope was employed to investigate the mechanism of fatigue damage growth. The observation indicated that the cracks between the warps and wefts were the major damage occurring during fatigue loading. Such cracks spreaded out with loading cycles resulting in decreasing of the residual strength.
Badawi, Said Sobhey [Verfasser]. "Development of the weaving machine and 3D woven spacer fabric structures for lightweight composites materials / Badawi, Said Sobhey." 2007. http://d-nb.info/987189700/34.
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