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Cannot compute eigenfrequency with impedance boundary condition.
Posted May 8, 2015, 8:22 a.m. EDT RF & Microwave Engineering, Studies & Solvers Version 4.4 1 Reply
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Hello,
When I follow an eigenfrequency tutorial to the dot, I cannot get the simulation to compute with an impedance boundary condition without the typical 'undefined stiffness matrix' error. These are the exact steps I do:
Make box of 28x8x8 mm dimension.
Define built-in material air as interior domain and aluminium as all boundaries.
Select the eigenfrequency study as part of EM, frequency domain physics and search for eigenfrequencies around 7e9 Hz.
Set the impedance boundary condition to all boundaries.
I set the mesh to finer, but I also tried at extremely fine, and it gave the same error.
Only when I disable the impedance boundary condition do I get it to compute the eigenfrequencies.
This is just a simple demo, but I need the impedance boundary condition of my materials for more complex setups but I cannot seem to get rid of this error. I have attached my file so that you can tinker with it.
Any help would be appreciated.
When I follow an eigenfrequency tutorial to the dot, I cannot get the simulation to compute with an impedance boundary condition without the typical 'undefined stiffness matrix' error. These are the exact steps I do:
Make box of 28x8x8 mm dimension.
Define built-in material air as interior domain and aluminium as all boundaries.
Select the eigenfrequency study as part of EM, frequency domain physics and search for eigenfrequencies around 7e9 Hz.
Set the impedance boundary condition to all boundaries.
I set the mesh to finer, but I also tried at extremely fine, and it gave the same error.
Only when I disable the impedance boundary condition do I get it to compute the eigenfrequencies.
This is just a simple demo, but I need the impedance boundary condition of my materials for more complex setups but I cannot seem to get rid of this error. I have attached my file so that you can tinker with it.
Any help would be appreciated.
Attachments:
1 Reply Last Post May 8, 2015, 10:19 a.m. EDT
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Posted:
10 years ago
Martijn,
I can tell you that it solves without problems in version 5.0 but not in 4.4. I have no idea why this happens. May be a case for the support.
Cheers
Edgar
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Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com