On the fatigue life prediction of CFRP laminates using the Electrical Resistance Change method
Φόρτωση...
Ημερομηνία
Συγγραφείς
Vavouliotis, A.
Paipetis, A.
Kostopoulos, V.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Composites Science and Technology
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The electro-mechanical response (Electrical Resistance Change method) as a damage index of quasi-isotropic Carbon Fiber Reinforced (CFRPs) laminates under fatigue loading was investigated. The effect of dispersed Multi-Wall Carbon Nanotubes (MWCNT) into the epoxy matrix was additionally evaluated and compared with neat epoxy CFRPs. The longitudinal resistance change of the specimens was monitored throughout the fatigue experiment. Three different stress levels were tested. The frequency and the ratio (R) of the minimum applied load (stress) to the maximum applied load (stress) were kept constant for the different stress levels. The temperature of the specimen was also monitored throughout the process in order to deduce its effect on the electrical resistance of the specimen. The electrical behavior of the quasi-isotropic CFRP deviated from the commonly observed electrical response of unidirectional or cross-ply CFRPs due to the presence of the 45 degrees layers. During initial stages of loading the resistance drops and afterwards it follows a positive slope up to final fracture. This repeatable pattern was observed for both the neat and the CNT-doped specimens, with the latter having smoother electrical recordings. The effect of temperature was calculated to be limited for the specific material and test/measurement configuration. The electro-mechanical response was correlated to stiffness degradation and acoustic emission findings enabling the identification of the specific regions during the fatigue life referring to specific mechanisms of damage accumulation. More specifically the experimental results revealed that the occurrence of the initial drop of the electrical resistance is linked with the occurrence of the Characteristic Damage State (CDS), associated with a specific percentage of stiffness reduction. This finding was used in order to predict the remaining life independently from the applied stress level with a high degree of confidence, assuming a constant stress level throughout the whole lifetime. The remaining life prediction for the CNT-doped specimens had higher coefficient of confidence (R(2)). (C) 2011 Elsevier Ltd. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
life prediction, fatigue, electrical properties, carbon nanotubes, cfrp, polymer-matrix composite, carbon-fiber, damage detection, mechanical strain, unidirectional cfrp, potential technique, acoustic-emission, piezoresistivity, resistivity, nanotubes
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000289137100009
http://ac.els-cdn.com/S0266353811000315/1-s2.0-S0266353811000315-main.pdf?_tid=b1d755a2be78a57c59e8693ff8712936&acdnat=1339672949_4bf098b9cd017de189e358c33f705892
http://ac.els-cdn.com/S0266353811000315/1-s2.0-S0266353811000315-main.pdf?_tid=b1d755a2be78a57c59e8693ff8712936&acdnat=1339672949_4bf098b9cd017de189e358c33f705892
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Μηχανικών Επιστήμης Υλικών