FEMM returned unexpectedly high flux densities for my problem. Whats going on?
FEMM will only give reasonable results if you are interpolating between defined points on the B-H curve for the material. Depending on your particular problem, you may need to add points to your B-H curves so that you are always interpolating rather than extrapolating. For nonlinear AC problems, there is also another factor at play. In this type of problem, FEMM is solving for the amplitude of the fundamental part of the field, which allows bigger values of flux density to appear than would be possible in a magnetostatic solution. For example, consider a material that saturates at about 2 Tesla. Imagine that at some point in the material, the flux density is traversing a a square wave versus time, varying between -2 Tesla and 2 Tesla. This would be analogous to an AC problem in which the material was subjected to a high degree of saturation. In this case, the amplitude of the fundamental is 2 Tesla * (4/π ), or 2.54648 Tesla. Although the peak value considering all harmonics is 2 Tesla
