Mechanical Properties of Composites Containing Exfoliated-Graphite/Epoxy Sensors

Abstract

One structural health monitoring (SHM) approach involves the embedding of sensors within a composite. However, embedded sensors may act as defects and could affect the composite’s mechanical properties. The objective of this study is to determine the effects of embedding exfoliated graphite (EG)/epoxy sensors on the mechanical properties of the hosting composite system. EG/epoxy composite sensor strips with two different volume fractions were fabricated. Two sets of tensile test specimens were fabricated by embedding the sensors in the epoxy system along the length and width directions of the test specimens. To develop a data baseline, EG/epoxy tensile test specimens were also fabricated. Tensile tests were performed on the samples and the results were analyzed to determine the effects of the embedded sensors on the composite material’s elastic modulus and tensile strength. The addition of EG slightly increased the elastic modulus and tensile strength of the samples. For test samples containing the sensor strips, the orientation of the sensors has a significant effect on the composite’s mechanical properties. Samples containing sensors along the widthwise direction were observed to have a lower tensile strength, and this is attributed to the observed delamination along the edge of the sensors.