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Permanent Magnet

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Hello All,

I am fairly new to Comsol and I am just beginning to learn about Magnetics. I am trying to model a permanent magnet in Comsol of 0.6T. As a result, I define the material properties as 0.6T, but when the analysis is complete, it only shows a max of 0.45T or so. Is there a reason it does this? I thought by defining it as 0.6T, that it should be max value. I would appreciate any input you all may be able to provide.

Thanks,
Jim

4 Replies Last Post 19 mars 2010, 01:20 UTC−4
Robert Koslover Certified Consultant

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Posted: 1 decade ago 11 févr. 2010, 13:27 UTC−5
The values of magnetic material parameters such as Br and Hci do not all by themselves tell you directly what local B and H fields will be. The magnet's geometry and the details of the magnetic circuit (including air, iron, etc) all matter a great deal. You need to learn more about permanent magnets and magnetic circuits.

For detailed guidance, see for example:
Permanent Magnet Materials and their Application (Cambridge Studies in Magnetism)
by Peter Campbell.

www.amazon.com/Permanent-Materials-Application-Cambridge-Magnetism/dp/0521566886/ref=sr_1_10?ie=UTF8&s=books&qid=1265912503&sr=1-10
The values of magnetic material parameters such as Br and Hci do not all by themselves tell you directly what local B and H fields will be. The magnet's geometry and the details of the magnetic circuit (including air, iron, etc) all matter a great deal. You need to learn more about permanent magnets and magnetic circuits. For detailed guidance, see for example: Permanent Magnet Materials and their Application (Cambridge Studies in Magnetism) by Peter Campbell. http://www.amazon.com/Permanent-Materials-Application-Cambridge-Magnetism/dp/0521566886/ref=sr_1_10?ie=UTF8&s=books&qid=1265912503&sr=1-10

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

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Posted: 1 decade ago 12 févr. 2010, 02:05 UTC−5
Hi

I can only agree, this book is short, concise and gives an excellent introduction.

if you want to go deeper into the maths there is also, as complement the series from Springer (several volumes) starting by:

www.amazon.com/Magnetism-Fundamentals-Etienne-Tr%C3%A9molet-Lacheisserie/dp/0387229671/ref=sr_1_4?ie=UTF8&s=books&qid=1265958130&sr=1-4

have a nice reading
Ivar
Hi I can only agree, this book is short, concise and gives an excellent introduction. if you want to go deeper into the maths there is also, as complement the series from Springer (several volumes) starting by: http://www.amazon.com/Magnetism-Fundamentals-Etienne-Tr%C3%A9molet-Lacheisserie/dp/0387229671/ref=sr_1_4?ie=UTF8&s=books&qid=1265958130&sr=1-4 have a nice reading Ivar

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Posted: 1 decade ago 12 févr. 2010, 14:45 UTC−5
Thank you both for your help and the book recommendations.
Thank you both for your help and the book recommendations.

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Posted: 1 decade ago 19 mars 2010, 01:20 UTC−4
Hi all,

i am a permanent magnet supplier, and also learn something about magnet, espesionally in the sintered NdFeB magnet field. if there is any i can do,just contact me?

Hi all, i am a permanent magnet supplier, and also learn something about magnet, espesionally in the sintered NdFeB magnet field. if there is any i can do,just contact me?

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