Discussion Forum

August 25, 2010 8:46pm UTC in response to Mike Bradley

Re: How to implement 2 piezo parts with different polling directions in 4.0a?

Hi

I can only confirm that I see too often "the relative error..." appearing, but at least in your case it is correctly stated (the relation is really bigger) I have often seen inconsitency in the values, still I do neither not know exactly what it means, nor how to avoid, but mostly my results are still coherent and as expected.

However, concerning the coupled analysis you have (if I understand you correctly) I wounder if it could be linked that you have (perhaps cannot really tell 100%) 2 physics with 2 solver states, or more, (i.e. eigenmode or harmonic for the driver and stationary for the receiver) but you have not managed (or COMSOL has not "understood" correctly how) to segregate the two. If my hypothessi is correct, then you should check the physics setting, and replace the "automatic solver selection" (close to the bottom of the window) by the user defined specific solver type for each(all) physics.

In V4, COMSOL does a certain number of hypothesis for multi physics - multi solver cases (in automatic mode), but does not always get it as we want it. Then we must decide which physics and which solver case shall be linked together.

I hit this issue some months ago I beleive with a pre-stressed eigenmode analysis in structural, and its not yet very documented, or just that I havent seen it

Hope this helps, if not "support" should be able to give you a better reply

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Good luck
Ivar

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