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Creating two Magnets with opposite Polarities

Posted Jun 23, 2014, 5:15 p.m. EDT Low-Frequency Electromagnetics Version 4.4 13 Replies

Edvin Golestanyan
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Dear All,

I want to create two magnets (Assume to blocks up and down with a distance from each other) that have opposite polarities so as a result they will repel each other. (see attached pic)

How can I do that?

Thank you.

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13 Replies Last Post May 27, 2015, 12:49 a.m. EDT
Robert Koslover Certified Consultant
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Posted: 1 decade ago Jun 23, 2014, 9:40 p.m. EDT
I've attached a basic model (uploaded without the solution to save memory) of what you described, as well as a picture showing the result after execution.
I've attached a basic model (uploaded without the solution to save memory) of what you described, as well as a picture showing the result after execution.
Edvin Golestanyan
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Posted: 1 decade ago Jun 24, 2014, 11:26 a.m. EDT
Dear Robert,

Thank you very much, but your file doesn't open and it gives a message of "comsol muliphysics model file is damaged or not valid".

Would you please fix and send me again.

I appreciate it.
Dear Robert, Thank you very much, but your file doesn't open and it gives a message of "comsol muliphysics model file is damaged or not valid". Would you please fix and send me again. I appreciate it.
Edvin Golestanyan
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Posted: 1 decade ago Jun 25, 2014, 3:35 p.m. EDT
Dear Robert,

Your file doesn't open and it gives a message of "comsol muliphysics model file is damaged or not valid".

Would you please fix and send it again.

Thank you.
Dear Robert, Your file doesn't open and it gives a message of "comsol muliphysics model file is damaged or not valid". Would you please fix and send it again. Thank you.
Robert Koslover Certified Consultant
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Posted: 1 decade ago Jun 25, 2014, 7:55 p.m. EDT
It works fine for me. Are you using the latest-updated version of Comsol Multiphysics 4.4 with the AC/DC module?
It works fine for me. Are you using the latest-updated version of Comsol Multiphysics 4.4 with the AC/DC module?

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Edvin Golestanyan
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Posted: 1 decade ago Jun 27, 2014, 11:15 a.m. EDT
Yes I am using Comsol 4.4 with all modules including AC/DC, but I can't open your file.

I have attached my sample, would you please fix and send it back, maybe in that case I would be able to open the file.

Thank you.
Yes I am using Comsol 4.4 with all modules including AC/DC, but I can't open your file. I have attached my sample, would you please fix and send it back, maybe in that case I would be able to open the file. Thank you.

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Robert Koslover Certified Consultant
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Posted: 1 decade ago Jun 27, 2014, 6:55 p.m. EDT
I may be mis-reading your file, but it appears that:
(1) you never defined your materials, and
(2) you did not include any volume of space around your magnets.
Both are essential before you can run your model. Every field region in the model requires material properties. And you must include plenty of space around your magnets, so that the fields can be computed within that space.
I may be mis-reading your file, but it appears that: (1) you never defined your materials, and (2) you did not include any volume of space around your magnets. Both are essential before you can run your model. Every field region in the model requires material properties. And you must include plenty of space around your magnets, so that the fields can be computed within that space.
Edvin Golestanyan
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Posted: 1 decade ago Jun 28, 2014, 1:11 a.m. EDT
Dear Robert,

I built this model without any data so you can build yours, because I can't open your file maybe I will be able to open this file.

I need to learn how can I define opposite polarities in the magnets.

Please insert all necessary data in that model as you did in yours. (The same way)

Thank you very much
Dear Robert, I built this model without any data so you can build yours, because I can't open your file maybe I will be able to open this file. I need to learn how can I define opposite polarities in the magnets. Please insert all necessary data in that model as you did in yours. (The same way) Thank you very much
Edvin Golestanyan
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Posted: 1 decade ago Jul 1, 2014, 12:07 p.m. EDT
I have updated my file, would you please tell how and where should I define opposite polarities in the magnets?

Thank you.
I have updated my file, would you please tell how and where should I define opposite polarities in the magnets? Thank you.

Attachments:

Robert Koslover Certified Consultant
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Posted: 1 decade ago Jul 1, 2014, 9:40 p.m. EDT
In your file, in the Model Builder, under Magnetic Fields, No Currents, choose Magnetic Flux Conservation (which is already in your list) or create a new one of those if you prefer. Select the domain of just one of the magnets to go with this. In the Magnetic Flux Conservation dialog, go to "Constitutive relation:" Choose "Magnetization". Put a number in for the z-component of M and leave the others zero. Now do the above all over again for the domain representing the other magnet, but specify the opposite sign for the z-component of M. This will point the two different values of M in opposite directions along z.
In your file, in the Model Builder, under Magnetic Fields, No Currents, choose Magnetic Flux Conservation (which is already in your list) or create a new one of those if you prefer. Select the domain of just one of the magnets to go with this. In the Magnetic Flux Conservation dialog, go to "Constitutive relation:" Choose "Magnetization". Put a number in for the z-component of M and leave the others zero. Now do the above all over again for the domain representing the other magnet, but specify the opposite sign for the z-component of M. This will point the two different values of M in opposite directions along z.
Edvin Golestanyan
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Posted: 1 decade ago Jul 2, 2014, 8:47 p.m. EDT
Thank you very much Robert.
Thank you very much Robert.
Edvin Golestanyan
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Posted: 1 decade ago Jul 7, 2014, 2:08 p.m. EDT
I have attached two models. Magnets are on tip of the rods.
In the first model, I have defined the magnets and fixed the end of the rods ( Solid Mechanics).
And I want to see the two magnets attract or repel each other but it seems Comsol doesn't do the coupling automatically! coupling of Magetic and solid mechanics.

In the second one, I have put body forces to the magnets equal to the force that Comsol Estimates in Magnetic module.

Now my question, is there any way that comsol will automatically calculate the magnets repelling/attracting forces and put it in solid mechanics as BC?

Or the only way is that I have done in second model.

Thank you.
I have attached two models. Magnets are on tip of the rods. In the first model, I have defined the magnets and fixed the end of the rods ( Solid Mechanics). And I want to see the two magnets attract or repel each other but it seems Comsol doesn't do the coupling automatically! coupling of Magetic and solid mechanics. In the second one, I have put body forces to the magnets equal to the force that Comsol Estimates in Magnetic module. Now my question, is there any way that comsol will automatically calculate the magnets repelling/attracting forces and put it in solid mechanics as BC? Or the only way is that I have done in second model. Thank you.
Edvin Golestanyan
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Posted: 1 decade ago Jul 10, 2014, 2:04 p.m. EDT
Dear Robert,

I have attached two models.
In the first one, I have defined the magnets and fixed the end of the rods ( Solid Mechanics).
And I want to see the two magnets attract or repel each other but it seems Comsol doesn't do the coupling automatically! coupling of Magetic and solid mechanics. Because the rods don't deform.

In the second one, I have put body forces to the magnets equal to the force that Comsol Estimates in Magnetic module. But this can't be correct since I am adding the forces direction manually, so it is not dependent to the polarity of magnets.

Is there any way to do this automatically? coupling solid mechanics with magnetic modules and see the deformation of rods due to polarity of magnets.

Thank you.
Dear Robert, I have attached two models. In the first one, I have defined the magnets and fixed the end of the rods ( Solid Mechanics). And I want to see the two magnets attract or repel each other but it seems Comsol doesn't do the coupling automatically! coupling of Magetic and solid mechanics. Because the rods don't deform. In the second one, I have put body forces to the magnets equal to the force that Comsol Estimates in Magnetic module. But this can't be correct since I am adding the forces direction manually, so it is not dependent to the polarity of magnets. Is there any way to do this automatically? coupling solid mechanics with magnetic modules and see the deformation of rods due to polarity of magnets. Thank you.
Ahmed Atrah
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Posted: 10 years ago May 27, 2015, 12:49 a.m. EDT
Dear Edvin Golestanyan
have you gotten the answer because I stopped in this point also.
Thank you
Dear Edvin Golestanyan have you gotten the answer because I stopped in this point also. Thank you

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