Result mesh single element/node picking and inspection

About the development of the FEM module/workbench.

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Walgri
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Joined: Sat May 09, 2015 10:16 pm

Result mesh single element/node picking and inspection

Postby Walgri » Thu Apr 18, 2019 12:01 pm

Hello,

is it possible in the GUI to pick and inspect the result values of a single finite element or node ?

Thanks
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bernd
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Re: Result mesh single element/node picking and inspection

Postby bernd » Fri Apr 19, 2019 6:04 pm

on vtk post processing tools is a tool for this, or use python or export to vtkfileformat an use paraview.
Walgri
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Re: Result mesh single element/node picking and inspection

Postby Walgri » Tue Apr 23, 2019 1:02 pm

Hi,

I'm a bit lost here.

I have sort-of managed to get the DataAtPoint, but I'm not sure what I'm getting, see attached screeshot: I was expecting a vector, not a scalar.
Clipboard03.png
Clipboard03.png (206.18 KiB) Viewed 305 times
Also, if I left-click on a result mesh face the Selection View (often, not always) reports a string like:
freecadfem2.Result_mesh.Elem543F1 (Resul_mesh)

But pretty often, for different faces the Selection View reports the same string:
freecadfem2.Result_mesh.Elem0F1 (Resul_mesh)

Nevertheless, I'm not able to inspect any of those in the python console.

Freecad version:

OS: Windows 7
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.16110 (Git)
Build type: Release
Branch: (HEAD detached at upstream/releases/FreeCAD-0-18)
Hash: f7dccfaa909e5b9da26bf50c4a22ccca9bb10c40
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: Italian/Italy (it_IT)


Please note that freecad reports Locale: Italian/Italy (it_IT), but my interface language is set to English. Not sure if this matters or not.
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bernd
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Re: Result mesh single element/node picking and inspection

Postby bernd » Tue Apr 23, 2019 1:49 pm

I must admit DataAtPoint is not as smart as it could be. The developer who made it vanished before he really finished the implementation. I did do some cosmetic to be able to merge but ... An option is to use Paraview.

Neverless it should work! Best is if you would post a simple example FEM analysis. A small one which has the vtk result obj still in the file. We could discuss the problems on this much better.

bernd
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bernd
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Re: Result mesh single element/node picking and inspection

Postby bernd » Tue Apr 23, 2019 1:51 pm

Ahh use latest 0.19 version of FreeCAD. Result obj. has changed ... All stress components are available now and naming is much better!

bernd
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bernd
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Re: Result mesh single element/node picking and inspection

Postby bernd » Tue Apr 23, 2019 1:52 pm

As far as I remember StressVectors in VTK are vonMises stress! Again use 0.19, you will have all what you need there in result object :)
Walgri
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Re: Result mesh single element/node picking and inspection

Postby Walgri » Tue Apr 23, 2019 1:59 pm

Uh, I just noticed that the value shown in the dialog box is the same for any point and DisplacementeVectors or StressVectors.

Please check if the attached file is complete enough to point out that behaviour. Thanks !
Attachments
freecadfem2.FCStd
(838.53 KiB) Downloaded 13 times
Walgri
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Re: Result mesh single element/node picking and inspection

Postby Walgri » Tue Apr 23, 2019 2:00 pm

bernd wrote:
Tue Apr 23, 2019 1:52 pm
As far as I remember StressVectors in VTK are vonMises stress! Again use 0.19, you will have all what you need there in result object :)
Thanks ! Will try !
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bernd
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Re: Result mesh single element/node picking and inspection

Postby bernd » Tue Apr 23, 2019 2:28 pm

Walgri wrote:
Tue Apr 23, 2019 2:00 pm
bernd wrote:
Tue Apr 23, 2019 1:52 pm
As far as I remember StressVectors in VTK are vonMises stress! Again use 0.19, you will have all what you need there in result object :)
Thanks ! Will try !
this is all we have in 0.19 ATM ... https://github.com/FreeCAD/FreeCAD/blob ... #L665-L696 More to follow if the the concrete stuff is merged, but only useful for concrete ... https://github.com/berndhahnebach/FreeC ... #L665-L705
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bernd
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Re: Result mesh single element/node picking and inspection

Postby bernd » Tue Apr 23, 2019 2:34 pm

Ahh in your screen the result mesh in visible. Be aware in FreeCAD FEM there are two totally independent PostProcessing systems. The FreeCAD result object uses a result mesh. On the contrary the vtk pipline can be used with all the filters (the green icons). BUT the green icons can not be used with the FreeCAD FEM result object. Thus you where in trouble I would assume ... Hopefully you got the point and the difference between the result objects.

Some development would be needed to merge all this into one. Ideas are around but development time is missing ...