Evaluation and impact of the degree of impregnation of uncured out-of-autoclave prepreg
Notice bibliographique
Résumé
Out-of-autoclave prepreg contains partially impregnated fibre tows which act as paths for gas evacuation. The degree of impregnation of resin into the dry fibre bed is a quantitative measure of the size of these dry fibre pathways and can affect part quality and rejection rates. There is no well-defined and accurate standard method to measure this quantity. The current state-of-the-art is to manufacture discriminator panels, which are panels containing complex features such as tight radius corners, internal ply drop-offs, sandwich regions, etc. to determine the producability of specific components by specific material. That is, it is an empirical method used to determine if the initial properties of the prepreg fall within certain boundaries. This technique is time consuming and does not necessarily account for variations within specific rolls of material. The aim of this thesis is twofold: examine different techniques to measure the degree of impregnation of out-of-autoclave prepreg and perform an experimental investigation into the impact of degree of impregnation on the breathability of the material.Firstly, different methods to quantitatively measure the degree of impregnation of out-of-autoclave prepreg are examined. Three methods are compared: X-ray computed tomography, the water uptake test, and active infrared thermography. The first method serves as a baseline for accuracy but is expensive both in terms of cost and time. The second method is characterized by its simplicity but is destructive and only gives local information over a small sample area. The latter method shows promise as a quick, non-destructive evaluation technique. A further investigation into active infrared thermography highlights some limitations of the technique with regards to its implementations in an industrial setting.Secondly, the impact of degree of impregnation on the gas transport phenomena in composite materials is evaluated by manufacturing single skin sandwich panels in an instrumented fixture with a simple design of experiments. Under room temperature conditions, as the degree of impregnation increases, the material's ability to transport gas is reduced, resulting in higher core pressure. However, at elevated temperatures, this impact is lessened and final laminate quality in all panels manufactured is similar.Both material and process variability is inherent in composite materials. Currently, it is important to use robust material systems and process cycles; however, through the use of non-destructive material inspection it would be possible to measure this variability and mitigate any problems caused by it through process modification or material rejection.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,002 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».