Analysis of incremental and differential permeability in NDT via 3D-simulation and experiment

• Published in: Journal of magnetism and magnetic materials Vol. 505; p. 166695
• Main Authors: Gabi, Y., Jacob, K., Wolter, B., Conrad, C., Strass, B., Grimm, J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2020; Elsevier BV
• Subjects: Coils; Computer simulation; Destructive testing; Ferromagnetism; Finite element method; Nondestructive testing; Permeability
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2020.166695

•In this paper, both NDT incremental and differential permeability methods are simulated via a 3D-FEM modeling taking into account the vector electromagnetic properties of the material.•In addition, the dynamic magnetic hysteresis behavior at different operating points is suggested.•Analytical algorithms of both permeabilities are described and assessed by comparison to experimental data.•The last section is dedicated to the challenges and steps of FEM modelling.•The simulated signals are compared and commented as a first validation. This paper investigates differential and incremental permeability in non-destructive testing application, evaluated by two different technologies, 1) using a ‘’yoke probe head’’ principal, via a surrounding coil; and 2) via a local receiver coil situated over the sample. The detected signals are simulated using 3D non-linear finite element method. The dynamic vector hysteresis nature of the ferromagnetic part is considered. The incremental permeability is calculated analytically and the profile is compared to measurement data. The FEM computed signals of both NDT technologies are compared to the experimental results, and show good agreement.