A. Vavouliotis

Multistage fatigue life monitoring on carbon fibre reinforced polymers enhanced with multiwall carbon nanotubes

Abstract In this study, CNTs were used as modifiers of the epoxy matrix of quasi-isotropic carbon fibre reinforced laminates. The prepared laminates were subjected to tensile loading and tension–tension fatigue and, the changes in the longitudinal resistance were monitored via a digital multimeter. In addition, acoustic emission and acoustoultrasonic techniques were used for monitoring the fatigue process of the laminates. The nanoenhanced laminates, on the one hand, exhibited superior fatigue properties and on the other hand, they demonstrated the full potential of the material to be used as an integrated sensor to monitor the fatigue life.

The effect of silicon carbide nanoparticles on the multifunctionality of epoxy polymers and CFRPs

In this work the effect of silicon carbide nanoparticles (n-SiC) into an epoxy matrix was investigated. High shear mixing techniques combined with sonication methods were used to homogeneously disperse the Silicon Carbide nanoparticles (Nano-SiC) in bisphenol-A epoxy resin at 1% weight fraction. SEM and AFM were used to evaluate the achieved dispersion in the nanopolymer. Mechanical, thermal and dynamic tests were performed to evaluate the nanopolymer and directly compared with the neat resin. On polymer level the produced materials showed improvement in the mechanical properties reaching up to 25% and 30% in Youngs modulus and failure stress respectively. The nanopolymer exhibited a more brittle behavior through the decrease of the maximum strain at fracture. The thermal properties of the nanocomposite were highly affected leading to an enhancement of the thermal conductivity and thermal effusivity of the material. Meanwhile the glass transition temperature increased up to 28% as measured through DMA tests. The aforementioned material was used as the matrix material in order to produce carbon fibre reinforced panel. The improved properties of the nanopolymer have enhanced the fracture properties of the composite material as the dispersed nanospheres can work as arrestors/deflectors of the propagating cracks through the composite.

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

In this study, CNTs were used as modifiers of the epoxy matrix of quasi-isotropic carbon fibre reinforced laminates. The prepared laminates were subjected to tensile loading and tension-tension fatigue and, the changes in the longitudinal resistance were monitored via a digital multimeter. In addition, Acoustic Emission and Acousto-Ultrasonic techniques were used for monitoring the fatigue process of the laminates. The nano-enhanced laminates on the one hand exhibited superior fatigue properties and on the other hand they demonstrated the full-potential of the material to be used as an integrated sensor to monitor the fatigue life.

Nano-modified CFRPs as a novel material for the manufacturing of high efficient antennas

The present work deals with the investigation of thermo-mechanical and electrical properties of nano-modified CFRPs in order to present the capacity to use this generation of novel materials in antennas applications. Among the issues discussed is the stiffness variation, the fracture toughness characteristics and the conductivity achieved at various levels of CNT doping of the epoxy matrix phase.