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Moving mesh does not work while the mechanical deformation is ok

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Hi all,

I have a question regarding to the moving mesh. Currently I am simulating a copper busbar with current injected, and there is a U-shield enclose the busbar. I want to see how the magnetic field line is going with the U-shield deforms. System looks like below:

What the main configured is that in the: 1. Solid Mechanics, set one side of the bus bar with Boundary load 1N, while the other side is fixed Constraint to make the Ushield deform. 2. Moving mesh, set the Prescribed x/y/z displacement to u/v/w as I do not know how the Ushield will deform in 3D direction. 3. Study I create Stationary study to solve all the physics.

Below is the result:

Seems the magnetic field lines are not going with the deformed Ushield. I tried a lot but not working. May I ask if someone knows the reason. Thanks in advance.


3 Replies Last Post Mar 3, 2020, 4:50 a.m. EST

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Posted: 4 years ago Mar 1, 2020, 9:52 p.m. EST

hi all,

I did a quick verify for only "Solid Mechnics" and "Moving mesh" to see if works. Unfortunately the Ushield's mesh is not moving after imposed 1N force load. Below is my Moving mesh configuration, I have no idea where goes wrong.

It will be much appreciate for the root cause. Thanks.

hi all, I did a quick verify for only "Solid Mechnics" and "Moving mesh" to see if works. Unfortunately the Ushield's mesh is not moving after imposed 1N force load. ![](https://wx2.sinaimg.cn/mw1024/817ecddegy1gcfe2i79cwj206208caah.jpg) Below is my Moving mesh configuration, I have no idea where goes wrong. ![](https://wxt.sinaimg.cn/mw1024/817ecddegy1gcfe569cjoj21150ccwgl.jpg?tags=%5B%5D) It will be much appreciate for the root cause. Thanks.

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 4 years ago Mar 2, 2020, 2:21 a.m. EST

Hi

For the solid parts the "moving mesh" is already there, included in the Physics via the deformed frame approach, however if you are looking into the magnetic fields you need to en sure your physics and the Maxwell equations are correctly solved, and this implies a closed volume and a closed I and B flux. But I do not see any "air" to close the field (?) ...

Then you need the moving mash in the air/vacuum domain, driven by the mechanics deformations, but not in the Solid parts.

So I suspect that is your issue. check the Library models and study these a bit better, they are really very helpful

Hope this helps on the way Sincerly Ivar

-------------------
Have fun COMSOLing,
Sincerely,
Ivar
Hi For the solid parts the "moving mesh" is already there, included in the Physics via the deformed frame approach, however if you are looking into the magnetic fields you need to en sure your physics and the Maxwell equations are correctly solved, and this implies a closed volume and a closed I and B flux. But I do not see any "air" to close the field (?) ... Then you need the moving mash in the air/vacuum domain, driven by the mechanics deformations, but not in the Solid parts. So I suspect that is your issue. check the Library models and study these a bit better, they are really very helpful Hope this helps on the way Sincerly Ivar

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Posted: 4 years ago Mar 3, 2020, 4:50 a.m. EST

Hi

For the solid parts the "moving mesh" is already there, included in the Physics via the deformed frame approach, however if you are looking into the magnetic fields you need to en sure your physics and the Maxwell equations are correctly solved, and this implies a closed volume and a closed I and B flux. But I do not see any "air" to close the field (?) ...

Then you need the moving mash in the air/vacuum domain, driven by the mechanics deformations, but not in the Solid parts.

So I suspect that is your issue. check the Library models and study these a bit better, they are really very helpful

Hope this helps on the way Sincerly Ivar

Hi Ivar,

Thanks a lot for the information. The visibility of the deformed mesh of Ushield can be obtained by adding "deformation" under "Mesh" in the 3D plot. I agree with you that it is already there.

The magnetic field line appears in the deformed Ushield as below successfully: MagneticFieldinUshield

However it seems still move meshing problem in the air. I am not sure what "air" means you refer, I created air domain for the system in order to see the magnetic field in the air also, the pic is attached: MagneticFieldinTheAir

For the air configuration in the Moving Mesh, after studying some Comsol library, I mainly used 1. "Prescribed Mesh Displacement" to keep the outline boundary of air domain 0 displacement. 2. Free Deformation to select air domain to make it adjust the mechnics deformation accordingly.

I am not sure where goes wrong, do I need PDE to calculate further?

>Hi > >For the solid parts the "moving mesh" is already there, included in the Physics via the deformed frame approach, however if you are looking into the magnetic fields you need to en sure your physics and the Maxwell equations are correctly solved, and this implies a closed volume and a closed I and B flux. But I do not see any "air" to close the field (?) ... > >Then you need the moving mash in the air/vacuum domain, driven by the mechanics deformations, but not in the Solid parts. > >So I suspect that is your issue. check the Library models and study these a bit better, they are really very helpful > >Hope this helps on the way >Sincerly >Ivar Hi Ivar, Thanks a lot for the information. The visibility of the deformed mesh of Ushield can be obtained by adding "deformation" under "Mesh" in the 3D plot. I agree with you that it is already there. The magnetic field line appears in the deformed Ushield as below successfully: ![MagneticFieldinUshield](https://wxt.sinaimg.cn/thumb300/817ecddegy1gcgvezl5w5j20dw0fejrv.jpg?tags=%5B%5D) However it seems still move meshing problem in the air. I am not sure what "air" means you refer, I created air domain for the system in order to see the magnetic field in the air also, the pic is attached: ![MagneticFieldinTheAir](https://wxt.sinaimg.cn/thumb300/817ecddegy1gcdo0siqw3j20gw0gpjur.jpg?tags=%5B%5D) For the air configuration in the Moving Mesh, after studying some Comsol library, I mainly used 1. "Prescribed Mesh Displacement" to keep the outline boundary of air domain 0 displacement. 2. Free Deformation to select air domain to make it adjust the mechnics deformation accordingly. I am not sure where goes wrong, do I need PDE to calculate further?

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