ABSTRACT
Alternating current field measurement (ACFM) and eddy current thermography are two non-destructive testing (NDT) methods widely used in industries. In this study, a combined NDT method based on the two methods is proposed. Firstly, some relative mathematical models are provided, and then an experimental system is designed for the combination of the two methods. The obtained magnetic field signal is smoothed by the double moving average method and crack identification and location are realised by using the method based on the morphological characteristics of Bx curve. Then, the thermal images are processed by a new method which is called virtual sensing technology (VST). It proves that VST can extract useful defect information from the images efficiently. The effect of excitation current on magnetic field and temperature field is studied and optimal current value is determined. Also, the effect of temperature and external magnetic field on magnetic field sensor is discussed. Finally, the future prospects of the combination of ACFM and eddy current thermography are discussed in this paper.
Disclosure statement
No potential conflict of interest was reported by the authors.