Inverse Analysis of Multiple Cracks Using Magnetic Flux Leakage Considering the Size of Flux Gate Sensor

In this study, multiple cracks on a structural member were detected using the magnetic flux leakage method. The distribution of magnetic flux density was measured using a flux gate sensor. A function that relates the magnetic dipoles and the magnetic flux density measured using the flux gate sensor was improved to capture the average value of the sensor length. The effectiveness of this improvement was verified through a numerical model with two adjacent semi-elliptical surface cracks. Cracks were detected separately using inverse analysis. In contrast, cracks were detected as being connected using the unimproved function.