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2D simulation on ZY plane

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Hello, I would like to simulate piezoleectric stack of AlN with electrodes on top and and bottom. So, the d33 component of the AlN is what I am observing. However I want to simulate in 2D (not axisymmetric) using ZY plane so I want to draw the cross-section assuming it's uniformly deep in X-direction. However, the default orientation of the 2D simulation os XY-plane. If I use this plane, the piezo-coefficient used the solver is not d33 .

Is it possible to switch to a different plane wiev for 2D simulations so Z pints up, Y-direction points right and X-direction points out from the screen? Thanks!

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Ozan Erturk

5 Replies Last Post Apr 3, 2020, 11:44 a.m. EDT
Dave Greve Certified Consultant

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Posted: 4 years ago Mar 27, 2020, 4:43 p.m. EDT

Under Solid Mechanics > Piezoelectric Material 1 select the appropriate material coordinate system.

Under Solid Mechanics > Piezoelectric Material 1 select the appropriate material coordinate system.

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Posted: 4 years ago Mar 30, 2020, 10:01 p.m. EDT

Thank you so much Dave! I changed both piezoelectric material and linear elastic material nodes as you suggested and I am geting more meaningful results. However I do have a small followup question. When I select the coordinate system for both nodes, the geomtery node still has the "x" and "y" coordinates for position of shapes, as opposoed to "x" and "z". I am assuming that these coordinate names are hardcoded and do not update themselves, they are x and y all the time regardless of the orientation of the plane chose, right? Just wanted to make sure.

Thanks again for your help!

-Ozan

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Ozan Erturk
Thank you so much Dave! I changed both piezoelectric material and linear elastic material nodes as you suggested and I am geting more meaningful results. However I do have a small followup question. When I select the coordinate system for both nodes, the geomtery node still has the "x" and "y" coordinates for position of shapes, as opposoed to "x" and "z". I am assuming that these coordinate names are hardcoded and do not update themselves, they are x and y all the time regardless of the orientation of the plane chose, right? Just wanted to make sure. Thanks again for your help! -Ozan

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Posted: 4 years ago Apr 1, 2020, 11:05 p.m. EDT

Also is there a way to change the entire coordinate system at once instead of going under each linear elastic material and piezoelectric material node to change the plane ?

Thanks again!

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Ozan Erturk
Also is there a way to change the entire coordinate system at once instead of going under each linear elastic material and piezoelectric material node to change the plane ? Thanks again!

Henrik Sönnerlind COMSOL Employee

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Posted: 4 years ago Apr 2, 2020, 5:15 p.m. EDT

Hi,

Unless you have orthotropic data, there is no need to change coordinate system for the Linear Elastic domains. And even then, it would be necessary only if you had chosen to enter the data in another system than XY.

It is rather uncommon with more than a single piezoelectric material in a model, so in most cases you only have to select coordinate system once.

I think you misunderstand what the coordinate system does. 2D models are always in the XY plane. If you have piezoelectric data which does not fit that, then you select a coordinate system for transforming the data into the XY-plane.

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Henrik Sönnerlind
COMSOL
Hi, Unless you have orthotropic data, there is no need to change coordinate system for the Linear Elastic domains. And even then, it would be necessary only if you had chosen to enter the data in another system than XY. It is rather uncommon with more than a single piezoelectric material in a model, so in most cases you only have to select coordinate system once. I think you misunderstand what the coordinate system does. 2D models are always in the XY plane. If you have piezoelectric data which does not fit that, then you select a coordinate system for transforming the data into the XY-plane.

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Posted: 4 years ago Apr 3, 2020, 11:44 a.m. EDT

Dear Henrik, Thank you so much for clarifying this issue. I think I now have a better understanding how the coordinate system works in 2D. Since 2D simulation always operate on XY plane if I have an anisotropic piezoelectric material, I select the "material" coordinate to translate the material plane to the simulation XY plane. For instance, thinking in 3D, if I want to use the z-direction E field to strain relation represented by the d33 coefficient of a piezoelectric material, then I choose the XZ plane of the material that translates X_material --> X_Sim and Z_material --> Z_Sim.

But for instance, if I want to simulate acoustic wave propagation in single crystal Si in 2D where the propagation is in z-direction thinking in 3D again. Translating this 3D problem into 2D simulation, I should not need to change the material plane orientation since elasticity matrix has equal magnitude in diagonal first three terms, right? However, if E_yy is different than E_zz then I will need to change the material coordinate system just as I do with the piezoelectric material.

Thank you again for your input!

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Ozan Erturk
Dear Henrik, Thank you so much for clarifying this issue. I think I now have a better understanding how the coordinate system works in 2D. Since 2D simulation always operate on XY plane if I have an anisotropic piezoelectric material, I select the "material" coordinate to translate the material plane to the simulation XY plane. For instance, thinking in 3D, if I want to use the z-direction E field to strain relation represented by the d33 coefficient of a piezoelectric material, then I choose the XZ plane of the material that translates X_material --> X_Sim and Z_material --> Z_Sim. But for instance, if I want to simulate acoustic wave propagation in single crystal Si in 2D where the propagation is in z-direction thinking in 3D again. Translating this 3D problem into 2D simulation, I should not need to change the material plane orientation since elasticity matrix has equal magnitude in diagonal first three terms, right? However, if E_yy is different than E_zz then I will need to change the material coordinate system just as I do with the piezoelectric material. Thank you again for your input!

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