Impact damage sensing in glass fiber reinforced composites based on carbon nanotubes by electrical resistance measurements

In this article, we report an interesting employment of multi-walled carbon nanotubes as a filler in the epoxy matrix of a glass fiber reinforced composite (FRP). The intrinsic electrical conductivity of carbon nanotubes made the development of a nanocomposite with enhanced electrical properties possible. The manufactured nanocomposite was subsequently employed in the production of a glass FRP. Due to the high aspect ratio of carbon nanotubes, very small amounts of these particles were sufficient to modify the electrical properties of the obtained glass fiber composites. Basically, a three-phases material was developed, in which two phases were electrically insulating—epoxy matrix and glass fiber—and one phase highly conductive, the carbon nanotubes. The main goal of this study was to investigate the possibility of developing a glass fiber reinforced nanocomposite (GFRN), which is able to provide measurable electrical signals when subjected to a low-velocity impact on its surface. Following this goal, the drop in the mechanical performance of the composite was evaluated before and after the impact. At the same time, the variation in its electrical resistance was measured. The results have shown that it is possible to associate the increase in electrical resistance of the composite with the formation of damages caused by impact. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011