High-order Simple-input Methods for Thick Laminated Composite Straight and Curved Tubes
Notice bibliographique
Résumé
Composites have proven their great potential for many aerospace applications, where high performance justifies high cost. One of the potential applications of composites is helicopter landing gears. Helicopter landing gears consist of straight and curved tubes. A new analysis and design tool is required to consider the manufacturing technology. In this study, high-order analytical methods are proposed to analyze and design thick laminated orthotropic straight and curved tubes subjected to different boundary and loading conditions. \nIn the first part of this thesis, the elasticity displacement field of thick laminated composite straight tubes is developed. In this investigation, thick composite cantilever tubes under transverse loading are studied using the newly displacement-based method. This method provides a quick, convenient and accurate procedure for the determination of 3D stresses in thick composite straight tubes subjected to both bending and shear loadings. In addition, this method is used to study stress and strain distributions in thick composite straight tubes with different simple and complex lay-up sequences. Note that thick laminated composite straight tubes subjected to cantilever loading conditions are investigated for the first time. Moreover, the developed method is used to analyze thick laminated composite straight tubes subjected to different mechanical loadings such as axial force, torque and bending moment. \nIn the second part of this thesis, the general displacement field of thick laminated composite curved tubes is developed. By proposing a new high-order displacement-based method, single-layer composite curved tubes are examined. First, a displacement approach of Toroidal Elasticity is chosen to obtain the displacement field of single-layer composite curved tubes. Then, a layer-wise method is employed to develop the most general displacement field of elasticity for thick arbitrary laminated composite curved tubes. The developed method is used to analyze single-layer and laminated composite curved tubes subjected to pure bending moment. Note that displacement-based Toroidal Elasticity is applied to study thick laminated composite curved tubes for the first time. In addition, the failure analysis on thick composite curved tubes subjected to pure bending moment is conducted. Effects of lay-up sequences of composite curved tubes on stress distributions and failure sequences are investigated, as well. \nThe accuracy of the proposed methods is verified by comparing the numerical results obtained using the proposed methods against finite element method, experimental data and solutions available in the literature. \nThe methods that proposed in this thesis do not require meshing. They simplify greatly inputs that the user has to do, once the program for solution is available. This presents a clear advantage over FEM. Therefore, the most important advantage of the proposed methods is that inputs for modeling and analyzing of composite straight and curved tubes with complex lay-up sequences are simple, easy to use and fast to run. In addition, using FEM for the parametric study is cumbersome. By applying the proposed methods, the parametric study for thick laminated composite straight and curved tubes is simple with low computational cost.
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 machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,004 | 0,001 |
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 source (Gemma direct ou Codex distillé), 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 ».