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Large difference between analytical solution and simulation results (error in model setup)

Posted 01.07.2011, 14:24 GMT-4 MEMS & Nanotechnology, MEMS & Piezoelectric Devices, Structural Mechanics Version 4.0a, Version 5.0 6 Replies

Mohamed Aref
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Hi all, I'am Mohamed Aref, and want to simulate cMUT and compare results with analytical solution, after setup model and get simulation results, i found large difference between analytical solution and simulation results (error in model setup).

cMUT is simply a parallel plate capacitor and I put voltage on the top plate and ground on button one, see the attached image.

This is the steps i done:
1- Modeling
2- Materials
3- Physics
>> in physics, first calculate force from (Force Calculation) and then set this force as boundary load,

Let's first compare between deformation in membrane due to electrostatic force

>> From analytical deformation at voltage=202 volts equal 0.5 um, and from simulation equal 4*10-11 m
so there is difference by factor 10^-4

I think that is error due to error in force calculation as it depend on the type of dielectric between the to electrodes which is air, as when i modeling the cMUT i can't define that this gap is air.

The model is attached, and i'll wait your replays, Thanks to you.
Best regards.

Attachments:

6 Replies Last Post 29.04.2015, 04:48 GMT-4
Mohamed Aref
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Posted: 1 decade ago 03.07.2011, 19:35 GMT-4
I don't understand how to setup Moving Mesh Physics for my cMUT model
any help please
I don't understand how to setup Moving Mesh Physics for my cMUT model any help please
wag dgsa
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Posted: 1 decade ago 28.03.2012, 01:19 GMT-4
Dear Mohamed Aref.

Could you send me a copy of your cmut model. i am also doing some research on CMUT simulation by means of COMSOL.

Best regards

mingjun
Dear Mohamed Aref. Could you send me a copy of your cmut model. i am also doing some research on CMUT simulation by means of COMSOL. Best regards mingjun
Sri Pasumarthi
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Posted: 1 decade ago 22.04.2014, 16:48 GMT-4
Hai, have u got the 3D CMUT module? If yes could u please provide me the design procedure I'm working on CMUT too

--
Sri Sairam Pasumarthi
Hai, have u got the 3D CMUT module? If yes could u please provide me the design procedure I'm working on CMUT too -- Sri Sairam Pasumarthi
Shubham Majumdar
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Posted: 10 years ago 03.03.2015, 14:48 GMT-5
Hi,
Can you send me the model please? Working on it, but getting errors.

Thanks.
Hi, Can you send me the model please? Working on it, but getting errors. Thanks.
Walter Frei COMSOL Employee

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Posted: 10 years ago 04.03.2015, 09:03 GMT-5
Dear Shubham,

For the type of modeling being described in this thread, we would recommend that you use the Electromechanics interface available in the MEMS Module. In particular, the following example is a good place to start with learning this interface:
www.comsol.com/model/electrostatically-actuated-cantilever-444
And then, to see what other types of modeling are possible with the Electromechanics interface, see:
www.comsol.com/model/biased-resonator-models-3d-11748

Please note that the approach described earlier in this thread, of manually combining electrostatics, moving mesh, and solid mechanics is a "legacy" approach and was made obsolete by the Electromechanics interface.

Best Regards
Dear Shubham, For the type of modeling being described in this thread, we would recommend that you use the Electromechanics interface available in the MEMS Module. In particular, the following example is a good place to start with learning this interface: http://www.comsol.com/model/electrostatically-actuated-cantilever-444 And then, to see what other types of modeling are possible with the Electromechanics interface, see: http://www.comsol.com/model/biased-resonator-models-3d-11748 Please note that the approach described earlier in this thread, of manually combining electrostatics, moving mesh, and solid mechanics is a "legacy" approach and was made obsolete by the Electromechanics interface. Best Regards
Dwekat
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Posted: 10 years ago 29.04.2015, 04:48 GMT-4
Dear Walter Frei ;
Thank you for such info.
I wonder if the " Electromechanics " interface also valid for non MEMS applications ?

Best Regards ;
Dear Walter Frei ; Thank you for such info. I wonder if the " Electromechanics " interface also valid for non MEMS applications ? Best Regards ;

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