ELMER GUI - Modal Analysis

The graphical user interface of Elmer
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FemUser1414
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Joined: 08 Nov 2017, 11:18
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ELMER GUI - Modal Analysis

Post by FemUser1414 » 08 Nov 2017, 13:15

Hello fellow Users

I am new to Elmer-Gui and Forums in general. So I do appreciate the support and the patience.

I am trying to complete a modal analysis of a simple square section bar (SIF attached): 10mm x 10mm x 100mm - Generic Steel Alloy - Free-Free.

Comparing the results of this model with hand calculations (Formulas for natural frequency and mode shape - Blevins) highlights "large" discrepancies (screen shot of spreadsheet attached)!

Am I doing something wrong?
I don't believe the deviations are related to mesh refinement (exercise has been completed but results are not attached).
I don't believe the deviations are related to the specific solver (exercise has been completed but results are not attached).

Please help.

Regards
FemUser1414
PS. I am not worried about the first 6 modes as predicted by Elmer because they are rigid-body modes.
PS. Additional information:
This exercise is just to get me familiar with this package. I am planing to use Elmer-Gui for a more elaborate application: Harmonic Analysis of a pre-stressed cylindrical object. This object is pre-stressed due to shrink-fit onto a more stiff and heavier part (not sure that I want to do Contact Analysis at this stage! Maybe after investigating the initial results)
Attachments
HandCalcsVsElmer.jpg
(191.86 KiB) Not downloaded yet
case.sif
SIF for Square bar
(1.87 KiB) Downloaded 31 times

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