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using Rayleigh Damping
Posted Jun 3, 2010, 9:46 a.m. EDT 3 Replies
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hi every one
i was modeling buddy floating. i was thinking to ad valye for i was modeling buddy (alfa and beta) any ideas how to calculte this factor ? or any hints to find out how its work
thanks alot
i was modeling buddy floating. i was thinking to ad valye for i was modeling buddy (alfa and beta) any ideas how to calculte this factor ? or any hints to find out how its work
thanks alot
3 Replies Last Post Nov 8, 2010, 1:02 a.m. EST
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Posted:
1 decade ago
Hi
Have you checked the pags 140++ of the smeug.pdf doc ? I believe that should give a reply, no ?
And do an indexed search of "Rayleigh Damping" on the docs, there are more in there, and in the other documents, even somewhere a matlab scripts to optimise the two variables
Have fun Comsoling
Ivar
Have you checked the pags 140++ of the smeug.pdf doc ? I believe that should give a reply, no ?
And do an indexed search of "Rayleigh Damping" on the docs, there are more in there, and in the other documents, even somewhere a matlab scripts to optimise the two variables
Have fun Comsoling
Ivar
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Posted:
1 decade ago
Hi Ivar,
I've checked the pages. I still think it's not that clear how to obtain the constants (alpha & beta). There is some information about damping in 'smeug.pdf' (pages 140-148, 199, 372). However, it seems that the procedure of the constant calculation is not clear. They address a reader to the Elbow Bracket example (smeug.pdf' pp 36-37). In this example, they assume that "the structure has a constant damping ratio of 0.1."...Actually, if we assume another number we will get different damping parameters.
I posted the question about this issue earlier (www.comsol.com/community/forums/general/thread/10886/)...
Please advise,
Stephan
I've checked the pages. I still think it's not that clear how to obtain the constants (alpha & beta). There is some information about damping in 'smeug.pdf' (pages 140-148, 199, 372). However, it seems that the procedure of the constant calculation is not clear. They address a reader to the Elbow Bracket example (smeug.pdf' pp 36-37). In this example, they assume that "the structure has a constant damping ratio of 0.1."...Actually, if we assume another number we will get different damping parameters.
I posted the question about this issue earlier (www.comsol.com/community/forums/general/thread/10886/)...
Please advise,
Stephan
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Posted:
1 decade ago
Hi
the thing is that most damping in structures are not a material parameter issue but an assembly issue (welding, bolting, crimping "sqeezing" ...) and for these there are only the measured values that are valid, all the rest is only hypothesis
--
Good luck
Ivar
the thing is that most damping in structures are not a material parameter issue but an assembly issue (welding, bolting, crimping "sqeezing" ...) and for these there are only the measured values that are valid, all the rest is only hypothesis
--
Good luck
Ivar