Menu

Discussion Forum

New Discussion
Filter

Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

How can I insert a Piezoelectric Device in a model that was created only with Pressure Acoustics and Solid Mechanics

Posted Dec 15, 2011, 12:22 p.m. EST Acoustics & Vibrations Version 4.1 3 Replies

Fabian Rojas
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hello,

I have a model that was created with Pressure Acoustics and Solid Mechanics. I use Solid Mechanics on some membranes so they can interact with pressure and I wanted to use Piezoelectric on this ones so I can see the relation between Voltage and Displacement.

When I put: 'Add Physics-->Piezoelectric Devices' my model stop working. Even if I disable Piezoelectric Devices and I try to make it work like at the beginning with Solid Works it doesn't want to solve the system. The first error that appears is: ' There is no feature tagged: 'mod1_V''.

I would appreciate if anybody can help me solving this problem so I don't have to restart the model.

Thanks in advance.

Fabian Rojas
3 Replies Last Post Dec 20, 2011, 3:15 a.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Dec 15, 2011, 3:52 p.m. EST
Hi

mixing in physics is not always that simple (works better in the newer versions) particularly as PZT physics include solid (again) so you end up with 2 "solid" physics. Normally COMSOL accepts this as the depedent variables receive new names i.e. u2,v2,w2, etc but then as user you will have some work to get the continuity to match as you need to make these formulations by hand. then when you remove a physics COMSOL tries at best to correct and set back tthe dangling equations, sometimes with unexpected and strange results.

In conclusion, my way: is always to reconstruct a model from scratch, you can have two models open, and copy the entry field formulas from one to the next, anyhow often this makes me clean up an old model already quite tampereed with, in this way I have very few issues, and far less similar variables to look after

--
Good luck
Ivar
Hi mixing in physics is not always that simple (works better in the newer versions) particularly as PZT physics include solid (again) so you end up with 2 "solid" physics. Normally COMSOL accepts this as the depedent variables receive new names i.e. u2,v2,w2, etc but then as user you will have some work to get the continuity to match as you need to make these formulations by hand. then when you remove a physics COMSOL tries at best to correct and set back tthe dangling equations, sometimes with unexpected and strange results. In conclusion, my way: is always to reconstruct a model from scratch, you can have two models open, and copy the entry field formulas from one to the next, anyhow often this makes me clean up an old model already quite tampereed with, in this way I have very few issues, and far less similar variables to look after -- Good luck Ivar
Fabian Rojas
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Dec 19, 2011, 8:19 a.m. EST
Thank you very much Ivar, you were very with the explanations.

Now, I have one more problem, maybe you can help me.

I have a model where I want to verify that a piezoelectric membrane will have her displacement proportional than the Electric voltage. My model send a acoustic planar wave that reacts with the membrane and I first try to find the resonance frequency of the membrane.

All the system work but when I get near the resonance frequency Comsol doesn't solve the problem and exceeds the number of itinerations and doesn't converge.

So is there any way to make it converge to have at least some approximative result?

Thank you in advance

Fabian Rojas
Thank you very much Ivar, you were very with the explanations. Now, I have one more problem, maybe you can help me. I have a model where I want to verify that a piezoelectric membrane will have her displacement proportional than the Electric voltage. My model send a acoustic planar wave that reacts with the membrane and I first try to find the resonance frequency of the membrane. All the system work but when I get near the resonance frequency Comsol doesn't solve the problem and exceeds the number of itinerations and doesn't converge. So is there any way to make it converge to have at least some approximative result? Thank you in advance Fabian Rojas
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Dec 20, 2011, 3:15 a.m. EST
Hi

most probably you do not have defined any damping in your model. without damping a resonance has its amplitude tending to INF which crashes the solver, try to add a few % viscous damping, or whatever you have as info on the actual damping (from the material and from the assembly) you can expect

--
Good luck
Ivar
Hi most probably you do not have defined any damping in your model. without damping a resonance has its amplitude tending to INF which crashes the solver, try to add a few % viscous damping, or whatever you have as info on the actual damping (from the material and from the assembly) you can expect -- Good luck Ivar

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content