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Stress simulation in electromagnets

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Hi Comsol-Community,

since quite some time I am trying to simulate high field electromagnets with Comsol 4.3.
When it comes to simpe field calculations of (mostly) 2D-axisymm. coil magnets everything is fine.
Even the combination with the structural mech. module is working well in some simple cases.
Sadly, my newest simulation attempt gives me quite some headache:

I want to simulate the coil and lateron the stress generated by the lorentz force of the coils
own magnetic field. The coils should have a few layers of wire. Each layer is supposed to have a reinforcement in the radial direction. The magnetic pressure pushes the wires outwards. Since there is no fixed connection between the reinforcement of an inner coil layer and the following layer of wires, I tried to form an assembly instead of a union and this is where the problems start. Now neither the mf nor the solid simulations are working:

1. mf: When using assemblies, there's no error during the solving process, but the magnetic field is now confined to the copper wires itself, probably due to an magnetic insulation boundary condition. How can I get rid of that?

2. So far I was using identity pairs. Is this right?

3. What do I have to do to make the solid mech. simulation run? All I want is that the the wire can only push but not pull. Is there a methode to accomplishe that without using assemblies?

I added a short example file...

Best regards,
Florian


1 Reply Last Post 16 gen 2013, 09:45 GMT-5
Nagi Elabbasi Facebook Reality Labs

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Posted: 1 decade ago 16 gen 2013, 09:45 GMT-5
Hi Florian,

When you use assemblies and identify pairs make sure you define proper constraints for these pairs in both the magnetic and solid physics. In the solid part for example you can do that by defining a continuity condition for the identity pairs. You can instead switch to contact pairs if you want something that can “push but not pull”.

Nagi Elabbasi
Veryst Engineering
Hi Florian, When you use assemblies and identify pairs make sure you define proper constraints for these pairs in both the magnetic and solid physics. In the solid part for example you can do that by defining a continuity condition for the identity pairs. You can instead switch to contact pairs if you want something that can “push but not pull”. Nagi Elabbasi Veryst Engineering

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