Feasibility Study of an Optimal Strain Gage based on Fluorescence Response of Graphene Quantum Dots

In this paper, based on the excellent fluorescence properties of graphene quantum dots and their good response to mechanical effects, graphene quantum dots are mixed with epoxy resin to make a coating sensor. Taking this as the research object, the film is coated on the Q235 tensile steel sample, which can dynamically monitor the stress and strain of the steel sample. By investigating the effects of the concentration of graphene quantum dots, the synchronization of the film and the steel component, and the residual stress of the epoxy resin, the mechanism of the visual fluorescence signal was analyzed. The response of stress-strain of steel specimen and fluorescence intensity of coating sensor under uniaxial tension and cyclic loading was studied. The experimental results show that the synthesized coating sensor has good stability and can produce very sensitive fluorescence response to stress and strain. The fluorescence intensity of the coating sensor increases with the increase of stress and strain under cyclic loading, and decreases with the decrease of stress and strain, which has the potential to act as a new optical strain gauge.