Research On Metal Crack Detection Of Microstrip Antenna Based On Flexible Graphene Film

Structural cracks will inevitably occur in the long-term use of metal structures,in order to prevent the deterioration of metal structure performance caused by cracks,it is necessary to detect metal structure cracks.Microstrip antennas have important applications in structural health monitoring due to their simple structure,small size,light weight,low profile,and easy conformality.Scholars at home and abroad have done a lot of research on the application of microstrip antenna sensors in the detection of flat metal cracks,but there are few researches on the crack detection of curved metal structures.Aiming at the problem of crack detection of curved metal structures,this thesis designs a conformal microstrip antenna metal crack sensor and a conformal microstrip antenna metal crack sensor array based on flexible graphene films.The specific research results are as follows:(1)A graphene conformal microstrip antenna metal crack sensor is designed and simulated by electromagnetic simulation software.The influence of the surface metal structure crack on the resonant frequency of the conformal microstrip antenna sensor is obtained by simulation,and the relationship between the sensor size and the sensitivity is discussed.The simulation results show that with the crack propagation of curved metal structure,the resonant frequency of graphene conformal microstrip antenna metal crack sensor will continue to decline,and millimeter cracks can be identified;At the same time,the larger the size of the sensor radiation patch,the lower the crack detection sensitivity.(2)The metal crack sensor of flexible graphene film conformal microstrip antenna is fabricated,the experimental platform of sensor crack detection is built,and the influence of curved metal structure crack on the resonant frequency of graphene microstrip antenna sensor is tested.The results show that the resonant frequency of graphene microstrip antenna sensor will continue to decrease with the crack length of curved metal structure.Finally,with the crack length decreasing linearly,the crack detection sensitivity is about 55.17 MHz / mm.At the same time,the crack detection performance of the sensor based on flexible graphene conformal microstrip antenna is compared with that based on metal copper,which proves the feasibility and effectiveness of crack detection of the sensor based on flexible graphene conformal microstrip antenna.(3)A graphene conformal microstrip antenna metal crack sensor array is designed and fabricated,and the detection performance of graphene conformal microstrip antenna metal crack sensor array is tested.The results show that the designed sensor array can solve the problem of decreasing the sensitivity of crack detection of traditional sensor array,and expand the crack detection range of graphene conformal microstrip antenna sensor.The research results of this thesis further prove the feasibility of the conformal microstrip antenna sensor based on flexible graphene for the crack monitoring of curved metal structure,realize the crack monitoring of millimeter curved metal structure,and expand the working field of microstrip antenna sensor to curved metal structure,which is of great significance for the practical application of microstrip antenna sensor in engineering.