Monitoring the thermomechanical response of aerospace composites under dynamic loading via embedded rGO coated fabric sensors

In this study, for the first time, the thermomechanical response of epoxy/glass fiber composites is reported using embedded reduced Graphene Oxide (rGO) coated glass fabric sensors subjected to dynamic loading. It was validated through experiments that the embedded rGO coated fabric sensors can be used to detect real-time changes in bending amplitudes and frequencies of an aerospace composite structure during its operation. In addition to thermomechanical and viscoelastic properties, the glass transition temperature (T_g) of the polymer matrix was also successfully monitored using the Dynamic Mechanical Analysis (DMA). It was concluded that the piezoresistive response of the composite structure was directly linked with molecular changes occurring within the polymer matrix chains, as the polymer transitioned from glassy to a rubbery state at different operating conditions. It was also demonstrated that these sensors are able to monitor simultaneously, any small changes in amplitude, frequency, and temperature, which are otherwise difficult to monitor in-situ. The developed smart aerospace composites were found to be very sensitive to any external stimuli, with very high level of repeatability in the obtained results, which was observed in both heating and cooling cycles of the DMA test. The rGO coated smart composites are finding applications in numerous composites industries, including aerospace where, composite structures experience varying levels of temperatures and dynamic mechanical forces during operation.