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Hi

Clear the mesh can be a cause, but also do you have enough free "air" around to allow the field lines to loop nicely ? that can easily give factors of "2".
But there are other reasons too, it could be caused from sharp corners on the iron or magnets, these make numerical singularities, and when you integrate the forces over the boundaries, you can easily get very wrong results. To avoid this use filleted corner, when possible, but this also increases the mesh density hece time to solution.

It's good to be able to compare measurements with the FEM theory, as like that you learn a lot about traps you should stear around ;)

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Good luck
Ivar

Hi Ivar,

Thanks for your advice.:)

I tried to simplify my model and cut the geometry into half along the symmetry boundary. Then I tried to refine the element size. The result is strange, almost 10% of the experimental data.

1. Increase the volume air that surrounding the whole part does not truly increase the deformation of the part.

2. Change the boundary condition from beam fixed end to simple supported does not change the result. What I did is change the fixed condition(x=0, y=0, z=0) to prescribed displacement(x=0, y=0, z is not zero)

3. I doubt the ALE was wrong. I only set the air to be deformable. The single bar has deflection due to the magnetic force. I think the single bar is also deformable, when setting ALE. I'm trying to running this. Should I use "deformed geometry" instead of ALE? I found the settings are almost the same.

4. Is there any way to do one way coupling analysis manully. For example, 1st step: Couple magnetic force to Solid mechanics model. 2nd step: Couple deformation in Solid mechanics model with AC/DC model. THEN repeat the former steps as iteration. I mean if I can ignore the ALE and use something else to express the change of mesh.

Thanks for your reply:)

Hi

it must be something in the way you have assembled the model, not evident to say more without opening it up and studying it ;)

Certainly you can solve physics by physics, one way is to make sequential solver steps and restriang one physics at the time, and link the next solver to the results from the previous one, you can also then separate the initial values reading for variables solved for and those not solved for. This is basically what the segregated solver is doing, but then running in an internal loop

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Good luck
Ivar

Hi Ivar,

Thanks for your reply.:)

You may see the attached file, which is partial of my model. Do you have any examples on the solving physics by physics?

Thanks again.:)

Dan

Add one moe thing, I tried the simulation with changing ALE(change mesh) to have air and the single bar. The result is still not good. Anyone has any suggestions?

Thanks.

Dani

Hi Ivar,

Thanks for your reply.:)

You may see the attached file, which is partial of my model. Do you have any examples on the solving physics by physics?

Thanks again.:)

Dan

Hi Ivar,

Would you mind taking a look at the model? Thanks.

Dani

please see the attached model and do me a favor. Thanks so much.

Im having the exact same problem... I also would be really thankful if someone can take a look at the simulation.

Thanks

Im having the exact same problem... I also would be really thankful if someone can take a look at the simulation.

Thanks

Im having the exact same problem... I also would be really thankful if someone can take a look at the simulation.

Thanks

Have you got any updated news?

Im having the exact same problem... I also would be really thankful if someone can take a look at the simulation.

Thanks

I think I worked out the problem by changing the ALE conditions. You may try to change the prescribed displacement from u to X+u, v to Y+v, w to Z+w.

Hello,

I have seen your question/model and the idea of the work you have for your thesis.
I am doing my master thesis as well and I have a problem with magneto structural coupling that probably you could help me in some way!
Would you be available? Or any way to contact you?

Best regards