magpylib-material-response

Warning This package is experimental and in development phase, breaking API changes may happen at any time.

Magpylib-Material-Response adds the response of magnetic materials to Magpylib: the demagnetization of hard magnets and the magnetization of soft-magnetic parts. It cuts the magnets into cells and solves for the polarization of every cell at once with the method of moments.

• apply_demag solves a magpylib Collection for a scalar or anisotropic susceptibility per cell, driven by remanent polarizations, a uniform applied field and the current sources in the collection.
• Two solvers, two interaction rules: a dense direct solver, or matrix-free GMRES with FFT products on grids of identical cuboids, for meshes too large for a dense matrix; the default solver="auto" picks one from the cells. Cells interact through the field at each other's centroids (default) or averaged over each cell (interaction="newell", cuboid meshes).
• Meshing helpers cut cuboids, cylinders and, through TetGen, any closed triangular surface into cells.

Installation

pip install magpylib-material-response

Tetrahedral meshing of TriangularMesh magnets requires the optional TetGen dependency:

pip install magpylib-material-response[tetgen]

Minimal example

import magpylib as magpy
from magpylib_material_response.demag import apply_demag
from magpylib_material_response.meshing import mesh_Cuboid

# a magnet with finite susceptibility, SI units (m, T)
magnet = magpy.magnet.Cuboid(polarization=(0, 0, 1), dimension=(1e-3, 1e-3, 1e-3))
magnet.susceptibility = 0.3  # µr = 1.3

# mesh into cells and solve; the result is a field source like any other
mesh_demag = apply_demag(mesh_Cuboid(magnet, target_elems=125))
print(magpy.getB(mesh_demag, (0, 0, 1.5e-3)))

See the documentation for a quickstart, worked examples, and the method description.