Dans un contexte législatif de plus en plus restrictif concernant les émissions de CO2, l’industrie automobile s’intéresse à l’utilisation des matériaux composites hautes performances pour alléger les véhicules. L’utilisation de ces matériaux pour des industries grand volume nécessite d’industrialiser leurs procédés de mises en œuvre, et notamment le préformage des renforts textiles. Il s’agit d’une étape clé puisqu’elle influe sur les paramètres morphologiques du renfort, qui impactent directement les propriétés du matériau composite. Pour leurs performances mécaniques, les Non-Crimp Fabrics sont un type de renforts textiles de plus en plus utilisé pour la fabrication de matériaux composites. Cependant, leurs modes de déformation sont particuliers et plus complexes que ceux des produits tissés, plus largement étudiés et utilisés. Le premier objectif des travaux de thèse présentés dans ce manuscrit est la compréhension des principaux modes de déformation des Non-Crimp Fabrics. Cette étude est effectuée d’abord au travers des différents tests de caractérisation sur plusieurs architectures de Non-Crimp Fabrics. Des études concernant l’Uniaxial Bias Extension test, qui permet la caractérisation en cisaillement plan des renforts, montrent que ce test est applicable aux Non-Crimp Fabrics en accord avec les hypothèses classiques. Des indicateurs évaluant la fiabilité du test ont été développés. Dans un second temps, une approche cinématique reliant les paramètres d’architecture des Non-Crimp Fabrics à leur déformabilité en cisaillement plan est présentée. Cette approche permet d’optimiser ou d’évaluer rapidement les structures des Non-Crimp Fabrics vis-à-vis de leur déformabilité en cisaillement plan.Le second objectif de ces travaux de thèse est le développement d’un procédé d’estampage séquentiel pour préformer des renforts, et notamment des Non-Crimp Fabrics. Dans un premier temps, un argumentaire géométrique permet d’orienter le développement du procédé d’estampage. Dans un second temps, la simulation numérique par éléments finis est utilisée pour optimiser le procédé vis-à-vis de la spécificité des Non-Crimp Fabrics. Un intérêt particulier est porté sur la calibration de la loi de comportement du matériau MAT140, utilisé dans le cadre de ces travaux de thèse. La corrélation entre la simulation et les résultats expérimentaux est systématiquement étudiée, tant à l’échelle des tests des caractérisations élémentaires qu’à l’échelle de la pièce réalisée. / Due to legacy restrictions concerning CO2 gas emissions, the automotive industry is interested in the use of high-performance composite materials to make vehicles lighter. The manufacturing of composite materials with high production rate requires to industrialize processes, and in particular preforming processes for textile reinforcements. Those processes are a key step since they determine the morphologic parameters of the reinforcements, which directly influence the composite material properties. For their mechanical behaviors, Non-Crimp Fabrics are a type of textile reinforcement more and more used for composite materials manufacturing. However, their deformation modes are specific and more complex than those of woven fabrics. The first aim of the thesis presented in this manuscript is the understanding of Non-Crimp Fabrics main deformation modes. Firstly, several Non-Crimp Fabric behaviors are analyzed thanks to tensile, bending and in-plane shear characterization tests. Specifically, the uniaxial bias extension test is studied and it is shown that the in-plane shear behavior of Non-Crimp Fabrics can be determined in accordance with the test classic assumptions. Moreover, indicators are developed to evaluate the reliability of the test. Secondly, a kinematical approach is presented. This geometrical analysis links the Non-Crimp Fabric parameters to the in-plane shear formability. This approach makes the evaluation and the optimization of Non-Crimp Fabric structures possible, from the in-plane shear formability point of view. The second aim of these thesis works is the development of a sequential stamping process to preform textile reinforcement, and Non-Crimp Fabrics in particular. Firstly, the process is designed thanks to geometrical and kinematical analyses. Secondly, numerical simulations, based on finite elements theory, are used to optimize the process design and the process parameters taking into account Non-Crimp Fabrics specificities. Fabrics are modelized with the MAT140 shell formulation. The calibration of this model is done and analyzed. Correlation between simulation and experimental results are systematically done at the characterization scale as well as at the preform scale.

Based on the underlying structure of fabric materials, a three-scale model is constructed to describe the mechanical behavior of fabric materials. The current model assumes that fabric materials take on an overall behavior of anisotropic membranes, so membrane scale is taken as the macroscopic or continuum scale of the model. Following the membrane scale, yarn scale is introduced, in which yarns and their weaving structure are accounted for explicitly and the yarns are modeled as extensible elasticae. A unit cell consisting of two overlapping yarns is used to formulate the weaving patterns of yarns, which governs the constitutive nonlinear behavior of fabric materials. The third scale, named fibril scale, zooms to the fibrils inside a yarn and incorporates its material properties. Via a coupling process between these three scales, the overall behavior and performance of the complex fabric products become predictable by knowing the material properties of a single fibril and the weaving structure of the fabrics. In addition, potential damage during deformation is also captured in the current model through tracking the deformation of yarns in fibril scale. Based on the multi-scale model, both static and dynamic simulations were implemented. Comparison between the static simulations and experiment demonstrates the model abilities as desired. Through the dynamic simulations, parameter research was conducted and indicates the ballistic performance and mechanical behavior of the fabric materials are determined by a combination of various factors and conditions rather than the material properties alone. Factors such as boundary conditions, material orientation and projectile shapes etc. affect the damage patterns and energy absorption of the fabric. / Mechanical Engieering

This thesis is founded in the positive psychological theory of gratitude, the experience of thankfulness and its benefits on both the individual and the community. My explorations via personal journaling, careful reflection, and engaging in craft, led me to cultivate a new definition for gratitude: present moment awareness. Using sheer fabric and the meditative act of embroidering, the language of gratitude was relearned and cultivated. My piece aims to incite further explorations in thanks.

A variety of materials were used to fabricate nanocoatings using layer-by-layer (LbL) assembly to reduce the flammability of cotton fabric. The most effective brominated flame retardants have raised concerns related to their toxicity and environmental impact, which has created a need for alternative flame retardant chemistries and approaches. Polymer nanocomposites typically exhibit reduced mass loss and heat release rates, along with anti-dripping behavior, all of which are believed to be due to the formation of a barrier surface layer. Despite these benefits, the viscosity and modulus of the final polymeric material is often altered, making industrial processing difficult. These challenges inspired the use of LbL assembly to create densely layered nanocomposites in an effort to produce more flame-retardant coatings. Laponite and montmorillonite (MMT) clay were paired with branched poly(ethylenimine) to create thin film assemblies that can be tailored by changing pH and concentration of aqueous deposition mixtures. Both films can be grown linearly as a function of layers deposited, and they contained at least 70 wt percent of clay. When applying these films to cotton fabric, the individual fibers are uniformly coated and the fabric has significant char left after burning. MMT-coated fabric exhibits reduced total heat release, suggesting a protective ceramic surface layer is created. Small molecule, POSS-based LbL thin films were also successfully deposited on cotton fabric. With less than 8 wt percent added to the total fabric weight, more than 12 wt percent char remained after microscale combustion calorimetry. Furthermore, afterglow time was reduced and the fabric weave structure and shape of the individual fibers were highly preserved following vertical flame testing. A silica-like sheath was formed after burning that protected the fibers. Finally, the first intumescent LbL assembly was deposited on cotton fabric. SEM images show significant bubble formation on fibers, coated with a 0.5 wt percent PAAm/1 wt percent PSP coating after burning. In several instances, a direct flame on the fabric was extinguished. The peak HRR and THR of coated fabric has 30 percent and 65 percent reduction, respectively, compared to the uncoated control fabric. These anti-flammable nanocoatings provide a relatively environmentally-friendly alternative for protecting fabrics, such as cotton, and lay the groundwork for rendering many other complex substrates (e.g., foam) flame-retardant without altering their processing and desirable mechanical behavior.

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Wrinkling caused in wearing and laundry procedures is one of the most important performance properties of a fabric. Visual examination performed by trained experts is a routine wrinkle evaluation method in textile industry, however, this subjective evaluation is time-consuming. The need for objective, automatic and efficient methods of wrinkle evaluation has been increasing remarkably in recent years. In the present thesis, a wavelet transform based imaging analysis method was developed to measure the 2D fabric surface data captured by an infrared imaging system. After decomposing the fabric image by the Haar wavelet transform algorithm, five parameters were defined based on modified wavelet coefficients to describe wrinkling features, such as orientation, hardness, density and contrast. The wrinkle parameters provide useful information for textile, appliance, and detergent manufactures who study wrinkling behaviors of fabrics. A Support-Vector-Machine based classification scheme was developed for automatic wrinkle rating. Both linear kernel and radial-basis-function (RBF) kernel functions were used to achieve a higher rating accuracy. The effectiveness of this evaluation method was tested by 300 images of five selected fabric types with different fiber contents, weave structures, colors and laundering cycles. The results show agreement between the proposed wavelet-based automatic assessment and experts’ visual ratings. / text

Abstract Prints and artwork in fashion are often made separately from the body and garment, processed through digital media and printed with mechanized precision. Far from the dynamic experience a painting can offer. This work elaborates how to build a collection of garments based on the body, using interactive methods. Its purpose and context is to find another print aesthetic in garment through abstract painting and cutting. In regard to the craft I hope to preserve the hands involvement as part of the expression. Suggesting another way to do prints in fashion that allow a more intimate relationship between body, fabric and color. This work explores the body-fabric relation through abstract painting to develop another print aesthetic and way of doing print. Hanging rectangular pieces of fabric over my head and energetically painting the fabric against the body results in an abstract approximation of the body-fabric relation. This approximation is analyzed by cutting and draping in regard to the painting and study of directions through lines. This method has generated a static approximation of the body-fabric relation which can be used as a tool for composing colors.

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The matching of colours on dyed fabric is an important task in the textile industry. The current method is based on the matching the visible reflectance spectrum to standard spectral libraries. In this study, the amount of dye on various wool and wool-blend fabric was measured using vibrational-spectroscopic techniques. FT-IR PAS and FT-Raman spectroscopy was used to analyse the following set of samples: woollen fabrics (supplied by CSIRO- Geelong, Australia), dyed with Lanasol dyes (Red 6G, Blue 3G and Yellow 4G) and wool/polyester fabrics (supplied by Ceiba-Geigy, Switzerland), dyed with Forosyn dyes (grey, yellow, green, brown, orange, red). A minimum of six spectra was recorded for each sample. The spectra recorded were consistent with those reported previously. FT-IR PA spectral data were block normalised with Y-mean centring and examined using Principle Component Analysis (PCA) and Partial Least Squares (PLS). Although PCA separates the woollen fabrics dyed with a combination of two colours, it does not do equally well for samples dyed with three colours. The dyed wool/ polyester blend samples appeared in a totally random fashion on the PCA plot. The PLS analysis of PA spectra of various ratios of dyes on woollen fabrics as well as wool/polyester blend was found to be a viable procedure and should be investigated further, perhaps with a broader set of data. FT-Raman spectra were examined using PCA and PLS. The best pre treatment for FT-Raman spectral data was found to be normalising followed by Y-mean centring. The PCA plots demonstrate that woollen samples are separated according to the dye ratios and that the presence or absence of some of the peaks is influenced by individual dyes. For example, the presence of the peak at 1430cm 1 is inversely related to the presence of blue dye on the fabric. The PLS resulted in SEE and SEP values of around 1 and 2 respectively indicating that the prediction of the dye ratios have not been very successful and suggesting that there was some problem with the measured values of the calibration set. PCA plots of wool/polyester fabrics dyed with a single colour indicate that PC1 separates the samples according to how close the shades are together, while PC2 and PC3 separate samples according to their individual colours. PC4, although explaining only a small percentage of variance, suggests that the samples are not homogeneously dyed. PCA plots of the samples dyed with various combinations of the three main dyes display each cluster of samples in their right position on the colour card. Calculated SEE and SEP values (Yellow: ~0.30, ~0.55, Brown: ~0.30, ~0.79, Red: 0.16, 0.49 and Grey: ~0.2, ~0.40, respectively) indicate that FT-Raman spectroscopy and chemometrics may offer promising methods for measuring the ratio of various dyes on wool/polyester fabrics. FT-Raman spectroscopy and chemometrics were also used to investigate the change in the ratio of dyes on UV-treated dyed woollen samples. Samples were weathered for 7 and 21 days, using accelerated weathering instrument. The substrate subtracted spectral data were normalised to 100% substrate of the first derivative (9 points and 7 degrees) followed by double centring of the matrix in the spectral region of 1500-500cm-1. PCA effectively separated non-irradiated from the irradiated sample but did not separate the irradiated samples further according to the number of days of irradiation. The pre-treatment used for PLS was first derivative of substrate subtracted spectral data normalised to 100% substrate, and then Y-mean centred. PLS failed to predict the ratio of the irradiated dyes very well. This may be because degradation products are not modelled by PLS or because the total amount of dye has reduced without changing the dye ratios.