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Failed to find a solution due to the relative error

Posted 10.04.2013, 13:01 GMT-4 MEMS & Nanotechnology, MEMS & Piezoelectric Devices, Structural Mechanics Version 4.3a 1 Reply

Gobong Choi

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Hello,

I am modelling piezoelectric sensor using MEMS module.
COMSOL was able to find the solution when I ran the frequency domain study with increment of 1HZ.
However, If I ran with smaller steps (ex. 0.1Hz or 0.2 Hz), I get the error massage saying that "the relative error is greater the the relative tolerance".
I have tried with finer mesh, but it didn't work.
I would like to know how to fix this problem.

Thanks!

Attachments:

cross-.mph

1 Reply Last Post 11.04.2013, 02:01 GMT-4

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

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Posted: 1 decade ago

Hi

nice model, ;)

I believe your issue is that you have no damping, and a very hiiigh Q factor, when you get too close to the resonance you get a numerical overflow, try using a log or power scale while approaching the resonance and skip just+/- something probably the solver will pass through, as for the larger steps

--
Good luck
Ivar

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Failed to find a solution due to the relative error

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