Detection of Cracks in Metallic Objects by Arbitrary Scanning Direction Using a Double U-Shaped Orthogonal ACFM Probe
摘要
Alternating current field measurement (ACFM) technology is developed for sizing cracks on structures. According to the theory of ACFM, the induced current should be perpendicular to the crack. So traditional ACFM probe needs to scan along the cracks. In this paper, a double u-shaped orthogonal ACFM probe is present for cracks detection by induced rotating current field at arbitrary scanning direction on structures. The finite element method (FEM) model is employed to analyze the rotating current field induced by the double u-shaped orthogonal ACFM probe. The cracks detection experiments are carried out to test cracks at arbitrary scanning direction. Results show that the crack can be detected effectively at arbitrary scanning direction using the double u-shaped orthogonal ACFM probe.