J. Phys. IV France 08 (1998) Pr2-681-Pr2-684
Field distributions in rotational single sheet testersA. Hasenzagl1, H. Pfützner1, A. Saito2 and Y. Okazaki3
1 Institute of Fundamentals and Theory of Electrotechnics, Bioelectricity and Magnetism Laboratory, University of Technology, Gusshausstrasse 27/351, 1040 Vienna, Austria
2 Faculty of Education, Tottori University, Tottori, Japan
3 Faculty of Engineering, Gifu University, Gifu, Japan
This paper concerns rotational single sheet testers (RSST) as applied for investigations of laminated soft magnetic materials. Most RSSTs use a square 64 cm2 sample with rather small sensor element. They yield effective average loss values for fine-grained SiFe rotationally magnetized up to 1.2 T. For highly grain oriented (h.g.o.) SiFe sheets, characterized by large grain size and high crystallographic order, we have developed a 3-phase existed RSST which uses a hexagonal sample of 166 cm2 area. It allows for increased induction values and for the application of large, well averaging sensors, the degree of flux homogeneity however being questionable. The aim of this study was a numerical estimation of the actual conditions of homogeneity for the two set-ups. Calculation was performed for the whole apparatuses by means of 2-dimensional FEM. The material was assumed to show uniaxial anisotropy with orthogonal principal directions for the permeability tensor. For both RSSTs, the results indicate good homogeneity of the induction vector B for the entire sample area. Effects of air gaps between sample and yokes prove to be less critical in the hexagonal case. In a second step, a heterogeneous model was used to simulate the magnetically hardest 55°-direction of Goss-textured material. With respect to the areally averaged vector interdependence between B and H, a comparison with measured results shows good qualitative agreement.
© EDP Sciences 1998