Disc permanent magnet pulling force - QuickField simulation example
Attraction of the disc magnet to a steel plate.
How to find pulling force of disc permanent magnets?
Answer Typical applications Geometry
Given
Task
Solution
Result
Reference
Engineering question
Set up an axisymmetric QuickField DC Magnetics problem for a disc permanent magnet and evaluate pulling force from computed field results.
disc permanent magnets, magnetic holding fixtures, magnetic attachment devices
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Simulation problem
Problem Type
Axisymmetric problem of DC magnetics
Rare-earth permanent magnet grade N40: relative magnetic permeability μ=1.05, remanence Br = 1.28 T.
Calculate the pull force of the magnet toward the steel plate and compare the results with the reference value.
We will measure the force between the permanent magnet and a thick steel plate of large diameter. Relative magnetic permeability of the steel plate μsteel = 1000.
Permanent magnet coercive force Hc = Br / μμ0 = 970 kA/m.
To calculate the pulling force accurately, and avoid integration along the edge dividing media with large difference in magnetic permeabilities, we place the magnet at a small distance δ = 1/1000" from the steel plate. Integration contour is drawn in the air around the magnet.
Pulling force is 2.56 N (0.57 lbs). Reference value is 0.56 lbs*.
*Neodymium Disc Magnet N40 3/16"x1/32" Rare Earth.
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