Crack Monitoring Sensor Based on Slow-Wave Substrate Integrated Waveguide

The local high-stress area of the metal facility will accumulate metal fatigue and produce damage such as cracks. The detection of tiny cracks on the metal surface can provide early warning of failure. In this paper, a structural health monitoring device based on a slow-wave substrate integrated waveguide (SW-SIW) is proposed. The miniaturization of the SIW can improve the sensitivity while the traveling wave characterization of the waveguide can improve the coverage and consistency. In the detection area, it is not sensitive to the crack position, and the longitudinal crack of 0.5 mm depth can be distinguished. The sensor uses the average value of the transmission coefficient as the feature. The detection sensitivity of crack depth is 14. S99/ mm. The proposed SW-SIW sensor provides a new idea for the large-scale coverage of electromagnetic sensors.