An Experimental and Numerical Investigation Into Vibration of Delaminated 3D Printed PLA Beams
Notice bibliographique
Résumé
<p>This report consists of several experimental and FEM-based numerical free vibration analyses of 3D printed PLA cantilever beam specimens. In the beginning, an introduction to the topic is given which includes an overview, organization of the report and literature review. Afterwards, the experimental setup including PLA specimens, Power supply, Laser interface and Input Laser sensors, is discussed. Experimental results, including frequency spectrum and fundamental frequency of defective, cantilevered, PLA beam specimens are evaluated, and average fundamental flexural (bending) frequencies are reported in the later section. The defect is considered to be a single, symmetric, through-the-width, centrally located delamination of various (0.5 mm, 0.25 mm, and 0.1 mm) delamination thicknesses, covering one-third of the beam specimens’ length. The average frequency values are calculated based on three different trials, conducted to ensure the accuracy of the obtained results. For the specimens with delamination thickness of 0.5mm, 0.25mm and 0.1mm, respectively, the fundamental frequencies are found to be 13.99 Hz, 13.36 Hz and 12.82 Hz. Theoretical results, including fundamental frequencies and corresponding mode shapes, obtained through simulations carried out using Finite Element Analysis (FEA) Software (Femap with NX Nastran) are also reported and discussed. For the PLA beam specimens with symmetric, through-the-width, centrally located, delamination of 0.5 mm, 0.25 mm, 0.1 mm, and 0 mm, respectively, the fundamental frequencies were found to be 16.26 Hz, 16.20 Hz, 15.89 Hz and 16.66 Hz. The mass of each PLA beam specimen (in kg) was also reported. The comparison is made between the numerical (FEM) and experimental results and reasonings are given for any discrepancies. </p> <p>Finally, the main findings are highlighted, and this report closes with conclusions, future </p> <p>considerations and. [sic] Future considerations include the possible aspect of the research that was not completed due to lack of time and resources. Appendix A includes an example of the theoretical and numerical vibrational analysis for a simple cantilever homogeneous (steel) beam. Appendix B explains numerical analysis of 3D-printed PLA beams, where the effect of system length on the fundamental frequency is demonstrated. It is observed that by increasing the length of the cantilever beam with 30mm (from 240 mm to 271 mm), the fundamental frequency decreases by 29.8%. Finally, Appendix C demonstrates a basic and introductory numerical contact analysis, assuming a coefficient of friction of 0.1, to calculate the contact pressure, contact force, contact traction, and contact stress. Contact analysis was done to understand the parameters such as contact force, contact stress and many more when the contact will occur. In contact analysis, certain parameters such as contact force, contact traction, and contact pressure was obtained through vibration analysis (without applied loading) and contact stress was obtained through static analysis (with applied loading). In this case, the gap was modelled with two surfaces touching each other. It was concluded from the results that very high loading will be needed to make contact happen. The content of this Appendix paves the way for the future vibration analysis of delaminated PLA beam including contact effects.</p>
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 | 0,000 | 0,000 |
| 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 ».