Thermally assisted consolidation of out-of-autoclave prepreg for concave parts
Notice bibliographique
Résumé
Vacuum Bag Only, Out-of-Autoclave prepreg processing offers a sustainable, cost-efficient alternative to conventional autoclave manufacturing of high strength composite parts.Flat or low curvature parts made with Out-of-Autoclave prepregs have demonstrated comparable mechanical properties to their autoclave counterparts, yet challenges still remain with the fabrication of parts with more complex features.One area of concern is corner thickening in concave corners.Best practices for reducing this defect exist; however, a more robust processing technique is desirable.In this work, a manufacturing process is proposed that involves heating the laminate during the vacuum bag compaction at regular intervals in the layup process.The aim of these heated debulks is to reduce corner thickening early on in the manufacturing process by encouraging inter-ply slipping, precipitating air removal, and increasing the degree of impregnation.Before the process could be designed, its potential was assessed through material characterization and demonstrator studies.Inter-ply friction was characterized for debulked samples using pull-out tests, allowing for a better understanding of the forces required to encourage prepreg slip.Dynamic mechanical analysis was used to assess changes in the degree of cure caused by debulking, and found a slight increase in curing with increased debulk temperature and duration.Investigating the removal of air from a tool-part interface showed no impact of heating on air removal rate.It was observed that air returned to the plies if vacuum was released when the resin viscosity was low.Initial trials were run on flat plates.There was a decrease in short beam shear strength as the debulk dwell temperature increased.Meanwhile, low temperature hot debulks led to an increase in voids.L-brackets were manufactured on a concave tool.The hot debulk led to a 25% reduction in corner thickening and a 80% reduction in void content compared to the part debulked at room temperature.Such improvements in quality motivated the development of a more robust design for a hot debulk process.This procedure consisted of using an infrared lamp to heat the prepreg, dry carbon fibre fabric as breather to absorb the heat while evacuating gases, and a bath of dry ice used to cool the tool before the vacuum bag was vented.In writing this, I have come to the end of more than five years of formation in the McGill Structures and Composite Materials Laboratory.During that time, I have had the privilege of working with some of the most admirable individuals and gained a wealth of experience.I am very fortunate to have had Pascal Hubert take me on as a masters student.Through him, I have been able to learn and experience so much.
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 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,001 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| 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 ».