Mesoscopic scale simulation of the Barkhausen effect for the characterization of steels
Barkhausen noise is more and more used as a measure of the health state of magnetic materials. It is indeed strongly correlated to materials microstructure, stress level and chemical composition for instance. In spite of its great practical interest, this measure is often hard to interpret due to the large number of underlying physical phenomena. The development of efficient and accurate modelling tools is thus necessary to enhance the understanding of measurement and access to more quantitative estimations of character-istic quantities, such as the level of stress or a rate of chemical component.
From the modelling point of view, the problem to solve is complex due to its multi-scale nature. Existing approaches can be divided in two families: those based on Monte Carlo methods to get a very fine description at the spin level, and those labelled as mesoscopic ones, aiming at solving a magnetostatic problem at the scale of the magnetic domains. In these latter approaches, Maxwell equations are solved considering a simplified configu-ration of domains in terms of geometry and displacements of domain walls.
This PhD subject consists in implementing an optimized simulation tool for the charac-terization of steels, based on a mesoscopic approach. This tool will exploit empirical considerations on the distribution and dynamic behavior of domain walls in view of de-riving macroscopic signals measured in practice and studying the statistics of character-istic parameters involved. Magnetostatic simulations will be carried out with a 3D nu-merical solver based on Finite Integration Technique (FIT) developed at CEA LIST. The representativeness of the unitary calculation will be the key to the validity of the statisti-cal procedure leading to macroscopic signals. Theoretical results will be compared to experimental data obtained in laboratory controlled conditions by partners of laboratoire Roberval (Université de Technologie de Compiègne, UTC), involved in the PhD work.
For more details contact Prof. Vafeas :
Assistant Professor Panayiotis Vafeas
Section of Process & Environmental Engineering
Department of Chemical Engineering
School of Engineering
University of Patras
26504 Patras | Greece
Telephone: +30 2610 996872 | Office
+30 2610 969581 | Laboratory
+30 6974 452995 | Mobile
Facsimile: +30 2610 996872