Strain Sensing with Nanoscale Carbon Fiber – Epoxy Composites

Abstract:

To study the electrical behavior of nanoscale carbon fibers (NCF)/epoxy nanocomposites under mechanical load, NCF/epoxy materials were produced using different mechanical dispersion methods like pearl mill and three roll mill. Various preliminary mechanical tests with simultaneous resistance measurements have been conducted. The influence of the filler content, the dispersion quality and the filler geometry on the electrical properties of NCF/epoxy composites was investigated as a function of the mechanical loading. The strain sensitivity strongly depended on the filler content and the filler geometry. In cyclic loading tests at low strains the resistance showed a reversible and linear behaviour. At higher strains irreversible resistance changes were observed. In addition, the specific surface resistance corresponded even during unloading with the highest strain level applied so far. This indicates the potential of NCFs/epoxy nanocomposites to monitor the loading history of a sample.