The following blog post discuss the magnetic stiffness calculation in 3D. It also include the example model file for your reference.

https://www.comsol.com/blogs/modeling-magnetic-bearings-in-comsol-multiphysics/

Hope this will be useful.

Best Regards,

Nirmal

The axial magnetic bearing tutorial is great, but i wanted to make a similar model in 3D so that I could calculate the force when the bearing was displaced in the radial axis. But it seems like I can’t apply the same method as in the tutorial, when I am trying to calculate the stiffness of the magnet. I use the sensiitivity and deformed geometry physics, in the same way as in the tutorial, but the calculations won’t converge. Do you have any idea about how I can calculate the stiffness with similar model in 3D?

Regards

Adam