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ver. 3.5a, Axial Symmetry (smaxi) offshoot of Cantilever Beam
Posted Apr 24, 2011, 11:04 p.m. EDT MEMS & Piezoelectric Devices Version 3.5a 1 Reply
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Dear all,
I am trying to model an offshoot of the Cantilever beam (as seen in model exchange). The "beam" I am using is a very thin cylinder with height of 0.34 nanometers and radius of 2.5 microns (I understand that this is a very large aspect ratio). The circular perimeter is fixed, so that the center area of the thin cyclindrical membrane deflects downward as a voltage is applied to a conductor below.
I'm attempting to model this in ver. 3.5a with 2D axial symmetry, hence using the following applications:
Axial Symmetry, Stress-Strain (smaxi)
Moving Mesh (ale)
Electrostatics (es)
Note: I am using Maxwell's stress tensor in the (smaxi) boundary settings because I do not have the MEMS module.
I'm receiving an error upon attempt to solve:
Failed to find a solution for the initial parameter:
No convergence, even when using the minimum damping factor.
Returned solution has not converged.
[with two warnings of inverted mesh elements]
Q1: Am I using the correct variables for the moving mesh subdomain and boundary settings for this axially-symmetric model? I understand that these variables may vary from the standard u,v, and w for regular 3D-space.
dr = R
dz = w
Q2: Are the simple Solver Parameters that I am using (Axial Symmetry analysis = static and Moving Mesh analysis = static) sufficient for this model?
Thanks for your time and help!
Best regards,
Kevin Myhro
I am trying to model an offshoot of the Cantilever beam (as seen in model exchange). The "beam" I am using is a very thin cylinder with height of 0.34 nanometers and radius of 2.5 microns (I understand that this is a very large aspect ratio). The circular perimeter is fixed, so that the center area of the thin cyclindrical membrane deflects downward as a voltage is applied to a conductor below.
I'm attempting to model this in ver. 3.5a with 2D axial symmetry, hence using the following applications:
Axial Symmetry, Stress-Strain (smaxi)
Moving Mesh (ale)
Electrostatics (es)
Note: I am using Maxwell's stress tensor in the (smaxi) boundary settings because I do not have the MEMS module.
I'm receiving an error upon attempt to solve:
Failed to find a solution for the initial parameter:
No convergence, even when using the minimum damping factor.
Returned solution has not converged.
[with two warnings of inverted mesh elements]
Q1: Am I using the correct variables for the moving mesh subdomain and boundary settings for this axially-symmetric model? I understand that these variables may vary from the standard u,v, and w for regular 3D-space.
dr = R
dz = w
Q2: Are the simple Solver Parameters that I am using (Axial Symmetry analysis = static and Moving Mesh analysis = static) sufficient for this model?
Thanks for your time and help!
Best regards,
Kevin Myhro
1 Reply Last Post Apr 25, 2011, 4:50 a.m. EDT
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Posted:
1 decade ago
Hi
You geometrical model need to be turned by 90°: the axial symmetry is vertical at r=0 (r & u replaces the "x" direction, and z and w replaces the Y direction, "phi" is out of paper with the loop length 2*pi*r)
Then do not forget that you can only study compression loads along Z (parallel to the axis of symmetry) or radial loads (of the type rotation around the axis of symmetry) in 2D-AXI
Correct your model then it will work better I assume
2D axis means tubes or round plates not really "cantilevers"
--
Good luck
Ivar
You geometrical model need to be turned by 90°: the axial symmetry is vertical at r=0 (r & u replaces the "x" direction, and z and w replaces the Y direction, "phi" is out of paper with the loop length 2*pi*r)
Then do not forget that you can only study compression loads along Z (parallel to the axis of symmetry) or radial loads (of the type rotation around the axis of symmetry) in 2D-AXI
Correct your model then it will work better I assume
2D axis means tubes or round plates not really "cantilevers"
--
Good luck
Ivar