The magnet is indeed one piece, I guess I didn't make that clear. The corners aren't as sharp as the models would indicate. Perhaps a better way to model it is with wedges that do not have corners that all meet at the same point (as shown in the attached model). If anyone has any suggestions I would be happy to hear them. This problem would be common to many magnets that don't have a rectangular cross section. (See attached file: Horseshoe 5.FEM) "David Meeker" <dcm3c@xxxxxxx> on 08/15/2001 05:44:12 PM Please respond to femm@xxxxxxxxxxxxxxx To: femm@xxxxxxxxxxxxxxx cc: (bcc: Peter Ceelen/BOCCT) Subject: [femm] Re: What is the best way to model Horseshoe magnets --- In femm@xxxx, "Peter Ceelen" <peter.ceelen@xxxx> wrote: > What is the best way to model a horseshoe (U shaped) magnet with the > poles on the top faces? The particular magnets I am trying to model > are a rectangular U in shape. I have modelled them as a single > body, as three bodies that meet at a 45 degree angle, and with > increasing numbers of wedge shaped bodies in the corners that > meet at correspondingly smaller angles as the number of bodies > increases. These all give different results and I am wondering > which of these ways is the most accurate. I have included simple > models as examples. [...] Hmmm--this is sort of an interesting question. The method with lots of wedges does act diferent because there's these little loops of flux that circulate by the interior corners, sort of constricting the flux path. Alternatively, the method with "three bodies that meet at a 45 degree angle" makes flux lines that practically turn a 90 degree corner at the joints, using the entire cross-section of the magnet. I'd guess that the most "accurate" way to model it would depend upon how you'd build the thing. I could imagine physically constructing it out of three pieces and actually building the "three bodies that meet at a 45 degree angle" configuration. But what I'm guessing that you are thinking of is building the U and magnetizing as one piece. You might have to do something subtle like try to model the U in the magnetizing fixture to see how it orients the magnetization. Anyhow, I know that there are a few list members who work at companies that design and manufacture permanent magnets. Any suggestions? Dave Meeker http://members.aol.com/_ht_a/dcm3c Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ ********************************************************************* This footnote confirms that this e-mail message has been scanned for the presence of known computer viruses by the MessageLabs Virus Control Centre. However, it is still recommended that you use local virus scanning software to monitor for the presence of viruses. *********************************************************************
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Horseshoe 5.FEM
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