A passive RFID sensor for crack detection on metal surfaces

This paper proposes a passive chipless RFID sensor for use in structural health inspection system, which utilises RFID technology for real time monitoring of cracks in building structures. The sensor device is composed of substrate, aluminium plate and antenna. The substrate material used is polyimide, the antenna is integrated into the substrate and the substrate is attached to the aluminium plate. The device can achieve a wide range of high-precision crack detection and can be widely used in crack detection in many fields such as construction, military, aerospace, ship, railway and so on. In this paper, the antenna in the sensor will be simulated using the microwave simulation software HFSS, and the results will be compared and verified by simulation. In this paper, the simulation results will be explored from two perspectives: with cracks and without cracks, and the experimental conclusions will be verified by seeking changes to the width of cracks on the basis of cracks, and also compared with other types of sensors in order to reflect the superiority of the passive chipless sensor. When a 0° crack is generated in the plane, the resonance frequency of the sensor will be linearly shifted to a lower frequency as the width of the crack gradually increases, and there is a certain proportionality between the magnitude of the resonance frequency change and the magnitude of the crack width change.