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Voltage Frequency Response measurment

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Hi everybody,

I attach a v4 COMSOL v4 file.It has two physics: Solid Mechanics and Electrostatics.

I am trying to simulate the response of the system when the parameter Vin is and AC voltage. I tried using a Frequency Domain analysis but it does not seem to work. Vin is not becoming an AC voltatge and, therefore, the force "Fes" either.

Can somebody give me a hand with that?

Thanks & have fun!


1 Reply Last Post 11.07.2010, 04:47 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 11.07.2010, 04:47 GMT-4
Hi

I believe it's because you have 2 physics solid and es (electroSTATIC) and the solving should be better segregated.

Then are you allowed to do Frequency Domain on ES ? I believe not from the DOC, not all physics allows all solving methods

If yes, you could apply segregated Frequency Domain to ES (the driving force) and Stationary to solid (the follower). But to do this you need to guide COMSOL on which solver to use on which physics.

To define yourself the solver per physics you should change the "SolidMechanics Advanced" tab "Automatic" to the specific solver. You also will notice that ES does not propose Frequency Domain, a clue that this is not implemented.
So I would rather try a MEF instead to check if the FD applies to the volts of the electric field. And then run only one physics, check that your forces are as expected, and only afterward couple both.

And define your pysics such that you can solve them correctly separate first. i.e in 2D axi the only "free" solid motion is vertical along z

Good luck
Ivar

Hi I believe it's because you have 2 physics solid and es (electroSTATIC) and the solving should be better segregated. Then are you allowed to do Frequency Domain on ES ? I believe not from the DOC, not all physics allows all solving methods If yes, you could apply segregated Frequency Domain to ES (the driving force) and Stationary to solid (the follower). But to do this you need to guide COMSOL on which solver to use on which physics. To define yourself the solver per physics you should change the "SolidMechanics Advanced" tab "Automatic" to the specific solver. You also will notice that ES does not propose Frequency Domain, a clue that this is not implemented. So I would rather try a MEF instead to check if the FD applies to the volts of the electric field. And then run only one physics, check that your forces are as expected, and only afterward couple both. And define your pysics such that you can solve them correctly separate first. i.e in 2D axi the only "free" solid motion is vertical along z Good luck Ivar

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