Finite Element Analysis Results and Analysis of Attraction Cases Between Like Poles of NdFeB Magnets

Abstract

A novel phenomenon of attraction between unequally sized magnet like poles with different permeance coefficients ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P_c</i> ) has been experimentally discovered. This attraction occurs only when a localized region of the low | <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P_c</i> | magnet reverses its polarity, forming an unlike pole region with respect to the high | <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P_c</i> | magnet. The attraction of like pole magnets is caused by the localized demagnetization ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LD</i> ) and is influenced by the factors, including the linearity of the BH curve, magnets’ geometries, and alignment. This paper reports more detailed finite element analysis (FEA) simulation and verification of the experimental results. Additionally, FEA simulation results for other untested unequally sized magnet pairs with various geometries are presented. The factors affecting the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LD</i> level, based on the field/force map from FEA results, are demonstrated. The potential of FEA simulation results for developing novel devices with unequally sized like poles in various applications is emphasized. The results have significant implications for the development of novel magnetic devices with enhanced performance and efficiency.