The hygrothermal ageing of epoxy resins and epoxy matrix composite materials has been studied many times in the literature. Models have been developed to represent the diffusion behaviour of the materials. For reversible diffusions, Fick, Dual–Fick and Carter $and$ Kibler models are widely used. Many parameters, correlated or not, have been identified. The objectives of this review by statistical analysis are to confirm or infirm these correlations, to highlight other correlations if they exist, and to establish which are the most important to study. This study focuses on the parameters of the Fick, Dual–Fick and Carter $and$ Kibler models. For this purpose, statistical analyses are performed on data extracted and calculated from individuals described in the literature. Box plot and PCA analyses were chosen. Differences are then noticeable according to the different qualitative parameters chosen in the study. Moreover, correlations, already observed in the literature for quantitative variables, are confirmed. On the other hand, differences appear which may suggest that the models used are inappropriate for certain materials.

Moisture content measurements are performed on scrapped Outlet Guide Vanes (OGV) that have operated in different climates. These measurements are made by three Karl Fischer titration methods. The results are separated into two parts. On one side, a comparison of these different techniques highlights their advantages and disadvantages. The methods for studying the samples and the duration of the tests differ. The standard method is not sufficient to extract all the water from the samples. The chemical extraction and grinding methods provide higher water content. On the other side, a mapping of the water content through three scrapped OGV blades is performed with the Karl Fischer titration. Differences are observed according to the service area climate. Concentration gradients are also visible within the part, with more water at the leading edges and less water in the foam. Parts that have flown in hot and humid regions have the lowest water contents by standard Karl Fischer titration. These measurements are compared with the analysis of the damage they have been subjected to. They allow to highlight the composite material degradation, manifested by resin erosion, which is more significant for parts that have operated in wet and humid areas. This erosion involves a lower resin percentage and could explain the lower water contents measured.

Ce travail vise à étudier les conséquences du vieillissement hygrothermique sur la réparation collée de matériaux composites tissés 3D carbone/époxy, qui constituent les aubes fans du moteur CFM LEAP. Dans un contexte d’introduction massive de pièces en matériaux composites à matrice organique dans les moteurs d'avions, la maîtrise de leur réparation, notamment par collage, devient essentielle et prend de l'essor. L'optimisation de ces réparations collées est rendue possible par l'utilisation de traitements de surface, comme le traitement plasma atmosphérique dont l'intérêt a déjà été prouvé. Cependant, ces pièces en composite sont sensibles aux conditions climatiques dans lesquelles elles évoluent, notamment la chaleur et l'humidité, et subissent de ce fait des dégradations. La première étape de ce travail a permis de mettre en lumière les paramètres influençant la diffusion d'humidité via une étude statistique. Par la suite, l'analyse des effets vieillissement hygrothermique sur les matériaux composites tissés 3D a mis en évidence des altérations physico-chimiques, massiques et surfaciques, telles que la migration de particules, un lessivage de la matrice, ou l'apparition de fissures, ce qui va affecter l'efficacité des collages. L'utilisation du plasma atmosphérique sur le matériau vieilli a montré un effet désorbant sur les surfaces et des niveaux d'oxydation semblables à ceux des surfaces neuves traitées au plasma, ce qui pourrait permettre d'activer chimiquement la surface en vue d'un collage et de restaurer certaines de ses propriétés. La caractérisation mécanique via des tests d’adhérence des assemblages matériau composite vieilli/colle a montré une nette amélioration de la résistance mécanique suite à l’utilisation du traitement de surface par plasma.

We propose a topological data analysis framework for the study of damage evolution in anisotropic composite materials based on scalar filtrations defined on cubical complexes. Two complementary anisotropic filtrations are constructed from the structure tensor: a fibre-oriented filtration f1, capturing directional coherence, and a crack-oriented filtration f2, sensitive to isotropic and weakly oriented structures. Zero-dimensional persistent homology is analysed through merge trees built from the superlevel-set filtration via the transformation $g=1-f$, providing a hierarchical representation of connected components. Higher-order connectivity is described using skeleton-based Reeb-like graphs. From these constructions, we derive spatial and global descriptors, including a topological danger map and a Topological Damage Complexity Index (TDCI) based on one-dimensional persistent homology. The behaviour of the TDCI is examined with respect to variations in its parameters and to image perturbations, showing consistent trends across the considered configurations. The results highlight complementary structural behaviours captured by the two filtrations and show a coherent correspondence with observed patterns. Overall, the proposed framework provides a mathematically grounded description of structural organisation. It is intended as an exploratory approach, and further work is needed to clarify its relationship with the underlying physical damage mechanisms.