Display principal stresses

About the development of the FEM module/workbench.

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HarryvL
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Re: Display principal stresses

Post by HarryvL »

bernd wrote: Fri Jun 29, 2018 5:01 am does it mean there is a bug in FreeCAD master here: https://github.com/FreeCAD/FreeCAD/blob ... #L429-L431 ?
Yes it does Bernd. But it only becomes important when dealing with principal stress directions.
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bernd
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Re: Display principal stresses

Post by bernd »

amstuff
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Re: Display principal stresses

Post by amstuff »

sorry for the (huge) delay. Unfortunately I'm still caught up in a lot other stuff and can't make the time right now. I'm however still committed to bringing this upstream eventually (can't tell when exactly though) and am checking by the forums every now and then.
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bernd
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Re: Display principal stresses

Post by bernd »

amstuff wrote: Thu Jul 12, 2018 6:24 pm sorry for the (huge) delay. Unfortunately I'm still caught up in a lot other stuff and can't make the time right now. I'm however still committed to bringing this upstream eventually (can't tell when exactly though) and am checking by the forums every now and then.
that would be surely very cool ! BTW do you know the FreeCAD motto ? It's done when it's done ...
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bernd
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Re: Display principal stresses

Post by bernd »

Rebased this on up to date master. I had to squash all commits since there where lots of naming issues. I spitted the commits in some other order to fit in FEM logic.

TODO:
- add a comment with link to this forum topic
- see post https://forum.freecadweb.org/viewtopic. ... 10#p195859 --> may be add as TODO in source code
- if a file is saved with glyph filter and vector stress and reloaded, and taskpanel is opened, the taskpanel sets back the vector to displacement
- I'm not fully happy with the cmake findpackage commit. This should may be done in global cmake of FreeCAD

https://github.com/berndhahnebach/FreeC ... mpostglyph
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bernd
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Re: Display principal stresses

Post by bernd »

the screen ... :D

Screenshot_20180911_214038.png
Screenshot_20180911_214038.png (420.25 KiB) Viewed 834 times
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HarryvL
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Re: Display principal stresses

Post by HarryvL »

Good progress Bernd. I am not sure I understand the results though. Stresses do not "flow" as expected from applied load to support. However, that is difficult to judge without scaling of the principal direction vectors. I would therefore suggest a small update where the length of the vector is proportional to the absolute value of the principal stress. Harry
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bernd
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Re: Display principal stresses

Post by bernd »

HarryvL wrote: Thu Sep 13, 2018 8:47 am Good progress Bernd. I am not sure I understand the results though. Stresses do not "flow" as expected from applied load to support. However, that is difficult to judge without scaling of the principal direction vectors. I would therefore suggest a small update where the length of the vector is proportional to the absolute value of the principal stress. Harry
I was really happy to get the branch rebased, compiled and could add the glyphs, until I had the same problem like you have :( The length should be scaled, that is true, but this will for sure take some more time I may not would like to spend right now ... There is another problem. Starting from 5000 nodes it gets slow. Above 100000 nodes one would wait ages ...
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bernd
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Re: Display principal stresses

Post by bernd »

ickby
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Re: Display principal stresses

Post by ickby »

I don't know any details, but imho you need to make sure to not have a glyph on each node. This will kill performance for sure and is unreadable anyway, as.glyphs are too close for finer meshs. You would need to interpolate the results and have use a certain glyph density, which the user could control. However. No idea how this should be imemented in vtk
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