Buckling Analysis

[FreeCAD97990]

I am very impressed by FreeCAD, and the FEM Workbench.

But I don't see an easy way of doing Buckling Analysis. Even though it is given lots of attention in, for example, COSMOSWorks.

Does anybody have any suggestions? Or have I missed something?

A way that I thought might be possible is to apply the compressive load (that is the Buckling Load) to the structure, and then to look at the Eigenmode Harmonic Frequencies as the compressive load is progressively increased. When the Lowest Eigenmode falls to zero, then that is the Buckling Load.

Does anybody alse have any thoughts on Buckling Analysis in FreeCAD?

[Jee-Bee]

Create static analysis.
Edit inp file
Change *STATIC according to https://feacluster.com/CalculiX/ccx_2.1 ... tml#buckle

There should be some examples on the forum too. But i'm on my phone so it is more difficult to find...

[thschrader]

Good morning.
Two days ago we had a webinar with Ideastatica (we use this software in our company):
“Stability analysis of arch-shaped members”
https://www.youtube.com/watch?v=ch7vW4kQvwM

The arch was calculated with RFEM from Dlubal (which we don’t use), then exported
to the Ideastatica “Member” module for performing buckling analysis and
geometric/material nonlinear analysis with imperfections.
I rebuilt this with FC and did the same calculations.
The results are a little bit different (buckling-factors, stresses) due to differences in
definition of the arc fixings and the model itself. RFEM/Ideastatica uses a polygon-shape,
FC uses a “real” arc. But in the end FC-FEM can do the same calculations like the commercial tools.
Have a nice weekend.

Here is the model (use netgen for meshing):

buckling_arc_20m.FCStd

(62.34 KiB) Downloaded 111 times

arc_buckling.JPG (108.66 KiB) Viewed 2732 times

Done with
OS: Windows 10 Version 2009
Word size of FreeCAD: 64-bit
Version: 0.20.25645 (Git)
Build type: Release
Branch: master
Hash: 37d9757399b4c2ec30318eb88d7cd7c508246345
Python version: 3.8.6+
Qt version: 5.15.2
Coin version: 4.0.1
OCC version: 7.5.0
Locale: German/Germany (de_DE)

[wingman]

Great share @thschrader.