Impact damage sensing of multiscale composites through epoxy matrix containing carbon nanotubes

Abstract

Carbon nanotubes are used to provide increased electrical conductivity for polymer matrix materials, thus offering a method to monitor the structure's health. This work investigates the effect of impact damage on the electrical properties of multiscale composite samples, prepared with woven fiberglass reinforcement and epoxy resin modified with as-received multi-walled carbon nanotubes (MWCNTs). Moreover, this study addresses potential bias from manufacturing, and investigates the effectiveness of resistance measurements using two-and four-point probe methods. Transmission electron microscopy and static tensile tests results were used to evaluate, respectively, the dispersion of MWCNTs in the epoxy resin and the influence of the incorporation of these nanoparticles on the static tensile properties of the matrix, and interpret results from the resistance measurements on impacted specimens. In this study, the four-point probe method is shown to be much more repeatable and reliable than the two-point probe method.

Sensing of large strain using multiwall carbon nanotube/segmented polyurethane composites

“…On the other hand, it has been proved that carbon nanotubes (CNTs) can provide electrical conductivity to electrically insulating polymers, 2,3 and they may also provide mechanically reinforcement. Coupling between the electrical conductivity and an external excitation can provide sensing capabilities to CNT composites, which can be used for measuring changes in glucose concentration, 4 impact damage 5 the presence of gases, 6 or liquids. 7 CNT/polymer composites with strain sensing capabilities have recently been also aggressively studied.…”

Investigation of the effect of carbon nanotubes on electrical properties of woven fiberglass/epoxy composite laminate

“…The method is used in measurements of semiconductor material resistivity. The 4-point method proved to be more reliable and repeatable than measurement by using two electrodes [7]. 4-point measurement scheme is shown on Figure 1.b.…”

Self-sensing carbon nanotube composites

“…Arronche et al [80] performed similar experiments for sensing of damage due to impact loads. The resistance changes that the group reported for their composite panel under impact loads were consistent with the work of Gao et al [79], but they reported significant differences in the values obtained by two-and four-wire methods.…”