التفاصيل البيبلوغرافية
| العنوان: |
Analytical modelling of fracture behaviour of delamination type specimens under mode II high-speed loading conditions ; Αναλυτική μοντελοποίηση της θραυστομηχανικής συμπεριφοράς συγκολλητών συνδέσμων υπό δυναμική φόρτιση τύπου ΙΙ |
| المؤلفون: |
Βλάχου Γκόμεθ, Έλλη |
| المساهمون: |
Vlajos Gomez, Ely |
| سنة النشر: |
2024 |
| المجموعة: |
University of Patras: Nemertes |
| مصطلحات موضوعية: |
Mode II fracture, End loaded split, High-speed loading, Beam vibration, Energy release rate, Timoshenko beam theory, Θραύση τύπου ΙΙ, Πειραματική διάταξη end loaded split, Υψηλοί ρυθμοί φόρτισης, Ταλάντωση δοκού, Ρυθμός απελευθέρωσης ενέργειας παραμόρφωσης, θεωρία δοκών Timoshenko |
| الوصف: |
In this work, an analytical model is developed for the calculation of the Energy Release Rate (ERR) under highrate mode II loading conditions, specifically at crack initiation. The model analytically represents an EndLoaded Split (ELS) specimen. Timoshenko beam theory is used to model both bonded and unbonded regions of the specimen and a simple contact condition is applied for the unbonded region. This study introduces the influence of shear in the dynamic behavior of the specimen under high- rate loading conditions through Timoshenko beam theory. It also investigates the presence of pure mode II conditions under high-rate loading. The presented analytical model is validated by a 2D FEA model that simulates the experiments. It is also compared with an analytical model available in literature, that uses the Euler-Bernoulli beam theory to model the specimen. Additionally, a method is suggested to determine a minimum threshold for crack initiation time, beyond which the loading conditions can be considered pure mode II when employing the standard EndLoaded Split configuration. The results demonstrate the dependency of the ERR on the vibrational characteristics of the specimen, highlighting that incorporating shear effects in the analytical model provides results closer to those obtained numerically. The study confirms that, in order to achieve pure mode II loading in an ELS specimen under high-speed conditions, displacement must be applied to both adherents. If the displacement is applied to both adherents, there is no need to model complex contact conditions. Also, the fact that symmetrical boundary conditions are applied, prevents the development of a mode I component in the ERR. ; Στην παρούσα διπλωματική εργασία, παρουσιάζεται η ανάπτυξη ενός αναλυτικού μοντέλου για τον υπολογισμό του ρυθμού απελευθέρωσης ενέργειας παραμόρφωσης (Energy Release Rate, ERR) υπό συνθήκες φόρτισης τύπου II (mode II) υψηλών ρυθμών για έναν σύνδεσμο End-Loaded Split (ELS), κατά την έναρξη της ρωγμής. Για να μοντελοποιηθεί ο σύνδεσμος ... |
| نوع الوثيقة: |
other/unknown material |
| وصف الملف: |
application/pdf |
| اللغة: |
English |
| Relation: |
https://hdl.handle.net/10889/28206 |
| الاتاحة: |
https://hdl.handle.net/10889/28206 |
| رقم الانضمام: |
edsbas.88F95414 |
| قاعدة البيانات: |
BASE |