Damage Monitoring of Structural Resins Loaded with Carbon Fillers: Experimental and Theoretical Study

In the present study, nanocomposite materials for structural applications with self-sensingproperties are proposed. In particular, suitable processing of epoxy resins filled with carbon nanotubesand expanded graphite characterized by very different aspect ratio leads to nanocomposite systemswith high glass transition temperatures and remarkable values of the gauge factor. In particular, thisnotable property ranges between four, for composites filled with one-dimensional nanofiller, and 39 forcomposites with two-dimensional (2D) graphite derivatives. The greater sensitivity of the 2D systemagainst permanent deformations is interpreted on the basis of an empirical mathematical model andmorphological descriptions. The larger inter-contact area among the graphite layers determines alarger contact resistance change than that occurring among carbon nanotubes. The proposed systemsturn out to be very advantageous in strain-sensor applications where damage detection is a keyrequirement to guarantee the reliability of the structures and the safety of the end-users.