Permanent magnet force

QuickField simulation example

This is a simulation example from Compumag TEAM Workshop Problem 23*.

Engineering question
How to find force between ring magnet and steel plate?

Engineering answer
Set up an axisymmetric QuickField DC Magnetics problem for a ring magnet and steel plate and evaluate force from computed field results.

Typical applications
ring permanent magnets, magnetic holding fixtures, magnetic clamps

Download simulation files (files may be viewed using any QuickField Edition).

Problem Type
Axisymmetric problem of DC magnetics

Geometry

Given
Permanent magnet Sm-Co coercive force H_c = 720 kA/m, remanence B_r = 1.06 T;
Coil number of turns 280, current I = 10.. 100 mA
Distance between the coil and the permanent magnet δ=0.254 mm.

Task
Calculate the axial force between the permanent magnet and the coil and compare the results with the reference values.

Solution
The coil has a lot of turns and is wound with an insulated wire, so the current distribution across the coil cross-section is considered to be homogeneous. The coil is modelled as a solid block with the total ampere-turns specified.
LabelMover parametric tool is used to generate a series of problems and calculate the force.

Result
The force value at I = 50 mA is 0.01096 N, which is equal to the gravity force acting on a weight of 1.117 g (1.5% less than the reference value of 1.132 g).

Reference
^*Compumag TEAM Workshop