Abstract
This paper focuses on the ability of carbon nanofibre (CNF) networks for in situ monitoring of fatigue induced disbond damage in carbon fibre adhesive bonded joints. The mode I fatigue delamination behaviour of composite joints bonded with an unmodified epoxy adhesive and 0.7 wt% CNF modified epoxy adhesive are evaluated. The inclusion of CNFs in the epoxy adhesive increases its conductivity by five orders of magnitude while simultaneously retarding the delamination growth rate. The mode I critical strain energy of the CNF modified adhesive increases by about five folds from 88 J/m2 to 450 J/m2 under cyclic fatigue loading. The improved electrical conductivity is utilized to evaluate the ability of the CNF network to monitor and detect the fatigue induced disbond damage by in situ measuring the resistance changes using a four probe setup. The changes in total resistance was a function of the bulk electrical resistivity of the adhesive and the bond dimensions, which were related to the disbond length to model and determine the size of the disbond. Good agreement were found between the optical disbond observations and the calculated disbond length using the in situ resistance measurements, therefore proving the ability of CNFs to not only detect delamination as small as 1 mm in composite bonded joints but also retard its growth rate.
Original language | English |
---|---|
Title of host publication | ICCM20 |
Subtitle of host publication | 20th International Conference on Composite Materials: proceedings |
Number of pages | 8 |
Publication status | Published - 2015 |
Externally published | Yes |
Event | 20th International Conference on Composite Materials, ICCM 2015 - Copenhagen, Denmark Duration: 19 Jul 2015 → 24 Jul 2015 |
Conference
Conference | 20th International Conference on Composite Materials, ICCM 2015 |
---|---|
Country/Territory | Denmark |
City | Copenhagen |
Period | 19/07/15 → 24/07/15 |
Keywords
- Nanocomposite adhesive
- In situ monitoring
- Disbond detection
- Fatigue delamination
- Electric resistance