Prof. Vassilis Kostopoulos Profile

Prof. Vassilis Kostopoulos

at Univ of Patras

SPIE Involvement:

Author

Proceedings Article | 8 April 2009 Paper

Multi-stage fatigue life monitoring on quasi-isotropic carbon fibre reinforced polymers enhanced with multi-wall carbon nanotubes: parallel use of electrical resistance, acoustic emission, and acousto-ultrasonic techniques

V. Kostopoulos, A. Vavouliotis, T. Loutas, P. Karapappas

Proceedings Volume 7294, 729409 (2009) https://doi.org/10.1117/12.821520

KEYWORDS: Resistance, Composites, Carbon, Acoustic emission, Epoxies, Polymers, Fiber reinforced polymers, Sensors, Carbon nanotubes, Aerospace engineering

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Proceedings Article | 30 March 2009 Paper

Nano-enhanced aerospace composites for increased damage tolerance and service life damage monitoring

A. Paipetis, T. Matikas, N. Barkoula, P. Karapappas, A. Vavouliotis, V. Kostopoulos

Proceedings Volume 7292, 72921O (2009) https://doi.org/10.1117/12.815210

KEYWORDS: Composites, Resistance, Epoxies, Tolerancing, Carbon, Polymers, Aerospace engineering, Carbon nanotubes, Manufacturing, Sensors

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Proceedings Article | 3 April 2008 Paper

Carbon nanotube epoxy modified CFRPs: toward improved mechanical and sensing for multifunctional aerostructures

Vassilis Kostopoulos, Antonios Vavouliotis, Petros Karapappas

Proceedings Volume 6929, 69292M (2008) https://doi.org/10.1117/12.785854

KEYWORDS: Resistance, Epoxies, Composites, Carbon, Sensors, Aerospace engineering, Polymers, Californium, Carbon nanotubes, Mechanical sensors

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In aerospace structures, the increase of mechanical performance of materials such as Carbon Fiber Reinforced Polymers (CFRPs) is always a key goal. In parallel, there is a constant demand for multi-functional solutions that provide continuous, integrated damage monitoring in an efficient and cost affordable way. Structural Health Monitoring systems are crucial for a variety of aerospace applications where safety, operational cost and the maintenance have increased significantly. The Electrical Resistance Technique (ERT) as a promising damage monitoring technique uses the CFRP materials themselves as inherent damage sensors. Currently method's medium sensitivity does not allow the identification of early damage stages requested for a potential application. By using highly conductive carbon-nanotubes as filler material into the epoxy matrix of CFRP is expected to increase the sensitivity of the method, allowing for wider field of applications. In addition, it is expected that the introduction of CNTs into the polymer matrix of CFRP laminates will increase the overall mechanical and electrical performance of the composite. This double role of the CNTs is investigated in the present study. Quasi-static tensile, cyclic loading-unloading-reloading with increase load level at each loading cycle and tension-tension fatigue tests with parallel monitoring of the longitudinal resistance performed on CFRP laminates with various contents of CNTs in the epoxy matrix showed that matrix cracking and fiber breakage caused resistance to increase irreversibly. Although the individual damage mechanisms could not be easily distinguished the overall damage state can be reliably characterized. Moreover significant increase in the fracture resistance was shown, for both Mode I and Mode II tests in the case of CNT doped laminates, compared against the reference laminate where neat epoxy matrix was used. Finally, low velocity impact tests showed that the CNT doped laminates appear to have reduced damage area based on C-Scan evidences.

Conference Committee Involvement (1)

Second International Conference on Smart Materials and Nanotechnology in Engineering

8 July 2009 | Weihai, China

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