Improved piezoresistivity and damage detection application of hybrid carbon nanotube sheet-graphite platelet nanocomposites

We fabricate carbon nanotube sheet - graphite platelet hybrid nanocomposites, determine their strain dependent electrical resistivity and demonstrate a damage detection application. The hybrid nanocomposites are prepared by infiltrating carbon nanotube sheets with epoxy modified by varying quantities of microscale graphite platelets. The electrical resistivity of the composites is measured while simultaneously subjecting them to mechanical loading. When the epoxy resin is modified with 5wt. % graphite platelets, the gauge factor of the hybrid nanocomposites shows a significant improvement from 0.5 to 10.6. Finally, the nanocomposites are used to detect a preexisting delamination in carbon fiber composites using flexural tests.