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calculate volume change, no domain
Posted 23 apr 2012, 09:43 GMT-4 Version 4.2a 2 Replies
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I'm doing a 2d axisymmetric simulation of membrane with piezo layer.
When it deforms I would like to know the volume created by the delection.
I'm not actually modelling this volume change, I only have solid materials in my simulation.
Would there still be a way to calculate this new volume?
Or do I need to simulate a volume of air?
When it deforms I would like to know the volume created by the delection.
I'm not actually modelling this volume change, I only have solid materials in my simulation.
Would there still be a way to calculate this new volume?
Or do I need to simulate a volume of air?
2 Replies Last Post 25 apr 2012, 06:19 GMT-4
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Posted:
1 decade ago
Hi
If I uderstand you right you have a radial membrane in 2D-axi and you observe some Z displacement hence deformation, and would like to know the volume that the deformed shape represents.
One way, indeed is to add a "air" volume, adjacent to your membrane, that is meshed, and that is so soft that it does not influence the deformation and calculate the integral before and after the membrane deformation and take the difference.
But I would also say you can integrate w*2*pi*r time implicit *dr along one of the edges of your membrane and get a volume from that, no ?
--
Good luck
Ivar
If I uderstand you right you have a radial membrane in 2D-axi and you observe some Z displacement hence deformation, and would like to know the volume that the deformed shape represents.
One way, indeed is to add a "air" volume, adjacent to your membrane, that is meshed, and that is so soft that it does not influence the deformation and calculate the integral before and after the membrane deformation and take the difference.
But I would also say you can integrate w*2*pi*r time implicit *dr along one of the edges of your membrane and get a volume from that, no ?
--
Good luck
Ivar
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Posted:
1 decade ago
When you integrate to obtain the volume of a cone shape, you describe the cone side as function of Z, so R(Z).
Where R describes the bottom edge of the membrane that is deflected.
You add the volume of discs with varying radius and infinitely small thickness.
So the math integral is V = int( r(z)^2 * pi ) dz
I am comparing it with a volume calculation assuming a cone shape. So linearized. And I have tried a couple of ideas using your suggestions, but none seem to match up.
My feeling would say that intop1(z^2)*pi would work, but it's quite off.
Any help would be much appreciated.
Where R describes the bottom edge of the membrane that is deflected.
You add the volume of discs with varying radius and infinitely small thickness.
So the math integral is V = int( r(z)^2 * pi ) dz
I am comparing it with a volume calculation assuming a cone shape. So linearized. And I have tried a couple of ideas using your suggestions, but none seem to match up.
My feeling would say that intop1(z^2)*pi would work, but it's quite off.
Any help would be much appreciated.