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Calculation of eigenfrequencies as a function of temperature

Posted Aug 19, 2020, 7:05 a.m. EDT Structural & Acoustics, Acoustics & Vibrations, Heat Transfer & Phase Change Version 5.3a 2 Replies

Simon Tait
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Hi,

I'm currenty trying to model the eigenfrequencies of a thin cylinder ansiotropic silicon cylinder as a fucntion of temperature in COMSOL 5.3a.

I have measured data for the material properites of the geometry between 4K-300K which i have loaded into the model and performed a parameter sweep through each of the properties while varying a temperature applied to the body.

Comparing the results of this model to measured data of eigenfrequency vs temperature yeilds very different results than I would expect. I am wondering if this is the best way to go about solving this kind if problem in comsol or if there is something that i am missing

2 Replies Last Post Sep 3, 2020, 6:45 a.m. EDT
Henrik Sönnerlind COMSOL Employee

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Posted: 4 years ago Aug 19, 2020, 9:15 a.m. EDT

This may be of interest:

https://www.comsol.com/blogs/how-to-analyze-eigenfrequencies-that-change-with-temperature

-------------------
Henrik Sönnerlind
COMSOL
This may be of interest:
Simon Tait
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Posted: 4 years ago Sep 3, 2020, 6:45 a.m. EDT
Updated: 4 years ago Sep 3, 2020, 6:55 a.m. EDT

Hi Henrik

Thank you for forwarding this article to me, it is indeed interesting. I have tried to take some tips from this model and apply it to my problem; however, I still seem to be having the same issue.

My current problem is that my measured eigenfrequencies increase with temperature, indicating that the stress inside the material is rising. The values which comsol predicts show an almost equal but opposite change in frequency with temperature.

I am wondering if there is something else which I need to take into account here for my model to represent the physical measurements accurately?

I will link below to dropbox transfer of my model so you can see what I'm working with.

https://www.dropbox.com/t/4NMOB3eYlric4kD0

Hi Henrik Thank you for forwarding this article to me, it is indeed interesting. I have tried to take some tips from this model and apply it to my problem; however, I still seem to be having the same issue. My current problem is that my measured eigenfrequencies increase with temperature, indicating that the stress inside the material is rising. The values which comsol predicts show an almost equal but opposite change in frequency with temperature. I am wondering if there is something else which I need to take into account here for my model to represent the physical measurements accurately? I will link below to dropbox transfer of my model so you can see what I'm working with. https://www.dropbox.com/t/4NMOB3eYlric4kD0

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