The BH nonlinear permanent magnet constitutive relation available in the Magnetic Fields and Magnetic Fields, No Currents is intended for easy modeling of self-demagnetization of soft permanent magnets, for example AlNiCo. It uses a nonlinear BH-relation that is isotropic around a point in H space that is shifted by the coercive field
Hc. The shifted B-H and H-B curves that are specified in the associated material node are thus supplied in the first quadrant, that is shifted by
Hc with respect to the uniaxial curve. The
AC/DC database in the
Add Material window contains an example material,
Nonlinear Permanent Magnet to be used with this constitutive relation. It is a generic/approximate representation of AlNiCo 5.