Ces travaux de thèse portent sur un composite à matrice polyamide 6,6 (PA66) renforcé d’un tissu de fibres de verre (Sergé 2/2). Dans le but d’une intégration dans des pièces automobiles, on s’intéresse au comportement de ce matériau sous sollicitation cyclique. L’objectif est de mettre au point un critère de fatigue permettant de prédire la durée de vie du composite étudié. Le PA66 étant sensible à l’humidité, il est nécessaire de prendre en compte ce paramètre dans notre étude. Pour cela, le matériau est conditionné selon trois états : un état sec (RH0), un état ambiant (RH50) et un état saturé en eau(RH100). Trois séquences d’empilement sont également considérées afin de tenir compte de l’orientation des fibres dans le matériau : [(0/903], [(90/0)3] et [(±45)3]. Dans un premier temps, l’influence du conditionnement sur les propriétés microstructurales et mécaniques en traction monotone est étudiée.Le rôle plastifiant de l’eau sur le PA66 a été mis en évidence. L’instrumentation des essais de traction monotone avec un système d’émission acoustique associée à l’observation post-mortem par MEB des éprouvettes permet de proposer un scénario d’endommagement en traction quasi-statique pour chaque configuration étudiée. Dans un deuxième temps, une campagne d’essais en fatigue traction-traction est menée sur les neuf configurations de l’étude. Ces essais ont permis la mise en place et l’évaluation de deux critères de fatigue phénoménologiques : les diagrammes de durées de vie constantes et le critère de fatigue à deux paramètres basé sur les courbes S-N. Ce dernier a été enrichi afin de pouvoir prédire la durée de vie du matériau pour différents conditionnements. De manière générale, le modèle montre une bonne capacité à prédire la durée de vie du matériau pour des conditions d’essais variées. Afin de cerner la capacité du modèle à être utilisé en bureau d’études, celui-ci a été appliqué dans le cas d’essais de fatigue menés sur une mini-structure sollicitée en flexion 3 points. / This study is focused on a woven glass-fibre-reinforced composite (2/2 twill) with a polyamide 6,6 matrix. From the perspective of its future integration in automotive parts, the fatigue behavior of this material is investigated. The aim is to develop a fatigue model able to predict the fatigue life of the composite studied. The PA66 behaviour is highly influenced by the moisture content, thus, it is necessary to take this parameter into account. Hence, three conditionings are studied: RH0, RH50 andRH100 which correspond respectively to the dry-as-moulded, the ambient and the water-saturated state.Three different stacking sequences are used in order to study the influence of fibre orientation: [(0/90)3],[(90/0)3] and [(±45)3]. First, the influence of moisture on microstructural and mechanical properties formonotonic tensile tests is studied. The plasticizing effect of water on PA66 has been highlighted. A damage scenario has been determined for every configuration studied by using acoustic emission technique during monotonic tensile tests and post-mortem SEM observations. Then, tension-tension fatigue tests are performed for all sample configurations. The results have been used to set up two phenomenological fatigue life models: the constant life diagrams and the two-parameter model based onS-N curves. The latter has been enhanced by including the relative humidity in order to be able to predict the fatigue life of the material for any conditioning. In general, this model estimates quite well the fatigue life of the material for different testing conditions. Finally, the two-parameter model has been used for fatigue life prediction of both open-hole samples and a mini-structure in order to evaluate its capability to be used in an industrial context.

In the advanced polymer composites reinforced by 3D woven fibre architectures, tows areinterlaced into through-thickness direction to overcome the problems encountered in theapplications of traditional 2D laminates, such as poor interlaminar toughness anddelamination resistance. The understanding of the influence of fibre architectures on thefatigue performance of 3D woven composites is essential in providing guide for the designof fibre architecture. This PhD project is an in-depth study into the fatigue damagemechanisms of 3D woven composites reinforced by two kinds of fibre architectures,namely, 3D modified layer-to-layer (MLL) and 3D angle-interlocked (AI). 3D X-raycomputed tomography (CT) has been used as the main tool to non-destructively evaluateand quantify the evolution of fatigue damage, with an attempt to link macro behaviour withlocal micro (damage) microstructure. Part I is focused on a post-failure study on both typesof materials to identify their respective failure mechanism, using the combination of 2D(optical surface and SEM cross-sectional) imaging and 3D (X-ray CT) imaging. Somecharacteristic features are found in both materials: firstly, fatigue damage progresses by theinitiation of transverse cracks within weft yarns and subsequent propagation as interfacialdebonding crack until the catastrophic failure occurs in a localised area; secondly, bothmaterials display a high resistance to ultimate failure. However, a distinctive damage modeobserved in MLL composites is the extensive development of debonding cracks, whichresult in larger scale of damage (~10μm) than those in AI composites (1-2 μm). Part IIpresents an investigation of evolution of fatigue damage in 3D woven MLL compositesfollowed by an X-ray time-lapse experiment. An innovative algorithm was developed toenable automatic classification of damage, providing insight into the competition andinteraction of different damage modes. Fatigue damage is regularly distributed throughoutfatigue life, with a geometrical dependency on the repeating unit cells. Damageinteractions have been identified, indicating a high level of damage tolerance. Aquantitative analysis has been carried out to examine and compare the growth of differenttypes of damage as a function of fatigue cycles. Transverse cracks initiate at almost thebeginning the fatigue life (0.1%) and govern the growth of weft/binder debonds, but don’tcompromise fatigue life, whereas interply debonds have a large growth towards the end offatigue life and facilitate the ultimate failure. Other types of damage occurring in the resinhave a trivial effect on the fatigue life. Part III carries out a systematic study to find out thebest approach to detect the fatigue damage in the 3D AI composites. Different strategieshave been employed in each scan, including imaging the cracks with the load applied, withcontrast enhanced by phases contrast and staining. The image contrast was not effectivelyenhanced by applying phase contrast imaging, but significantly improved by staining. Withthe application of in-situ loading, the visibility of transverse cracks is highly improved,while longitudinal debonding cracks still cannot be resolved. Overall, the best approachwas found to be high resolution ROI (region of interest) scanning in combination withstaining, in terms of practical feasibility, scan time and image quality.

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This thesis explores the origins of the House and Temple form through the design of a house. The design looks to the theory of the original elements of architecture being the hearth, roof, mound and woven enclosure. Specific focus is given to the woven aspect of this theory, which is expounded upon in the wood structure and partitions of the house. The house exhibits the characteristic syntax of weaving with orthogonal geometric relationships and a hierarchy of elements. The structure and spaces of the house emerge from a rigid pattern grid defining the site and the historic temple symbolism of the double square. / Master of Architecture

Electromagnetic wave absorbing properties of SiC-based and alumina ceramic woven fabrics have been investigated. Electrical conductivities of SiC-based ceramic woven fabrics were modified by heat treatment in air resulting in their oxidation. Surface properties of alumina woven fabrics were altered by gold-sputtering resulting in a high conductivity layer on the surface of the wovens. Electromagnetic wave interactions of single layer and double layered combinations of these ceramic woven fabrics were determined in 17-40 GHz frequency range using &ldquo / free-space&rdquo / method. Electromagnetic wave absorption potential of ceramic woven fabrics with different chemical compositions and woven types were correlated with their material properties by X-ray diffraction, scanning electron microscopy and electrical conductivity measurements. Effects of modifications and varying woven fabric arrangements in combinations on the electromagnetic wave absorption potential of the ceramic woven fabrics have been discussed. Various double layer combinations of SiC-based and alumina woven fabrics revealed a promising potential in terms of both reduced reflection and transmission resulting in more than ~95% absorption in millimeter wavelength range, which makes them powerful candidate materials for electromagnetic wave absorption applications.

Sammanfattning på svenska: Målet med projektet var att utveckla ett system av disperserade bindemedel för non-wovenindustrin som inte förutsätter omfattande förändringar i befintliga processer. Bindemedlet ska vara biobaserat, bionedbrytbart och endast bestå av byggstenar som är matkontaktsgodkända av FDA och BFR. Ett disperserat system möjliggör en hög torrhalt tillsammans med en låg viskositet som i kombination med stor anpassningsbarhet kan konkurrera med fossila bindemedel på marknaden. Denna studie behandlar användande och modifiering av vattenlösliga biopolymerer för utveckling av ett disperserat system med förmågan att binda samman fibrer i ett non-wovenmaterial. Flertal analytiska metoder och observationer används, som Fourier transform infraröd spektroskopi (FTIR), laddningsdensitet, viskositet och optisk mikroskopi, för att mäta framgången av konceptet. Olika modifieringar och ympningsstrategier användes under projektet och deras inverkan på biopolymerer diskuteras. / The aim of the project was to develop a dispersed binder as a drop-in solution for non-woven industry. The binder should be bio-based, biodegradable and consist only of FDA and BFR food contact approved components. A dispersed system enables the binder to have a high solid content while having a low viscosity. This feature, in combination with a binder with tunable properties, can be a competitive alternative for the fossil-based binders in the market.  This study focuses on the use and modification of biopolymers with binding capacity to form a dispersed system from water-soluble biopolymers. The success of the reaction was evaluated by using a multitude of analytical methods and observation, such as Fourier transform infrared spectroscopy (FTIR), charge distribution and viscosity measurements. Several modification strategies and grafting agents were used and their impact on the biopolymer is discussed.

Ce travail aborde trois problèmes fondamentaux liés au comportement mécanique de matériaux tissés. Dans une première partie, le modèle de Wang et Pipkin pour des tissés, décrits comme des réseaux de fibres inextensibles comportant une résistance au cisaillement et à la flexion, est généralisé en un modèle prenant en compte la résistance à la torsion des fibres. Une application au comportement d’une coque cylindrique constituée de fibres hélicoïdales est traitée. Dans une deuxième partie, nous analysons l’impact de la géométrie de l’armure du tissé sur les propriétés de symétrie de l’énergie de déformation. Pour des réseaux constitués de deux familles de fibres, quatre configurations distinctes d’armure existent, selon l’angle entre les fibres et les propriétés mécaniques des fibres. Les propriétés de symétrie de l’armure déterminent le groupe de symétrie matérielle du réseau, sous l’action duquel la densité d’énergie est invariante. Dans ce contexte, des représentations des énergies de déformation d’un tissé invariantes par le groupe de symétrie matérielle du réseau sont établies. La relation entre les invariants du groupe et la courbure des fibres est analysée. Dans une troisième partie, des modèles de textiles considérés comme des surfaces dotées d’une microstructure sont élaborés, à partir d’une modification des modèles classiques de coques de Cosserat, dans lesquels la microstructure décrit les ondulations des fils à l’échelle microscopique. A partir d’une représentation du fil comme un elastica d’Euler, une expression explicite de l’énergie élastique microscopique est obtenue, qui permet d’établir un modèle simple du comportement mécanique macroscopique de tissés / In this work, we discuss three basic problems related to the mechanical behavior of textile materials. First, we extend the model of Wang and Pipkin for textiles, described as networks of inextensible fibers with resistance to shear and bending, to a model in which resistance to twist of the individual fibers is taken into account, by including torsion contributions in the elastic stored energy. As an example, we study the behaviour of a cylindrical shell made of helical fibers. Second, we study how the geometry of the weave pattern affects the symmetry properties of the deformation energy of a woven fabric. For networks made by two families of fibers, four basic types of weave patterns are possible, depending on the angle between the fibers and on their material properties. The symmetry properties of the pattern determine the material symmetry group of the network, under which the stored energy is invariant. In this context, we derive representations for the deformation energy of a woven fabric that are invariant under the symmetry group of the network, and discuss the relation of the resulting group invariants with the curvature of the fibers. Third, we develop a model for textiles viewed as surfaces with microstructure, using a modification of the classical Cosserat model for shells, in which the microstructure accounts for the undulations of the threads at the microscopic scale. Describing the threads as Euler's elastica, we derive an explicit expression for the microscopic elastic energy that allows to set up a simple model for the macroscopic mechanical behavior of textiles

Este projeto, \"Influência do fator de cobertura nas propriedades de permeabilidade de tecidos planos\", descreve um breve histórico sobre a Tecelagem e seu crescimento na indústria Têxtil mundial, sendo muito importante o seu desenvolvimento para a indústria. Será apresentado também o conceito sobre Fator de cobertura de tecidos planos. Com o objetivo de avaliar a correlação entre o fator de cobertura e a permeabilidade dos tecidos planos, foram desenvolvidas 18 amostras de tecido com fio 60/2 Ne 100% agodão no urdume e na trama, em ligamento tela, sarja e cetim com densidades de trama 16tramas/cm, 24tramas/cm e 32tramas/cm, e com densidade de urdume 16fios/cm e 32fios/cm . Foi calculado o fator de cobertura para todas as amostras e foram realisados ensaios de gramatura, permeabilidade ao ar, permeabilidade ao vapor de água e permeabilidade a água, com a observação do indice OMMC (Capacidade de gestão global de umidade) do aparelho MMT (Moisture Management Tester). Este estudo se mostra como um caminho na Utilização do fator de cobertura, como item a ser considerado no desenvolvimento de novos artigos. Os resultados mostram para cada ligamento e fator de cobertura o comportamento com relação à permeabilidade dos Tecidos / This project, \"Influence of the coverage factor on the properties of permeability of woven\", describes a brief history on Weaving and its growth in the world textile industry, being very important its development for the industry. The concept of woven coverage factor, will also be presented. In order to evaluate the co-relation between the coverage factor and the permeability of woven, 18 wovens samples were developed with 60/2 Ne 100% cotton thread in the warp and the weft, inwoven twill and satin weave with warp weights 16 yarn/cm, 24 yarn/cm and 32 yarn/cm and with warp density 16 yarn/cm and 32yarn/cm. The coverage factor was calculated for all samples and weight, air permeability, water vapor permeability and water permeability tests were performed with the observation of the OMMC (Global Moisture ManagementCapacity) index of the MMT (Moisture Management Tester).This study shows as a path in the use of the coverage factor, as an item to be considered in the development of new articles. The results show for each ligament and cover factor the behavior regarding the permeability of the wovens