Surface loading
Moderator: bernd
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and Helpful information for the FEM forum
and Helpful information for the FEM forum
Surface loading
Hello,
I am new to freecad, I am experimenting with FEM.
When I apply the pressure constraint, there is a parameter (surface load), except there is no unit.
I want to know which unit is applied for this parameter.
Thank you.
My apologies for not following this procedure.
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.4 (GitTag)
Build type: Release
Branch: releases/FreeCAD-0-18
Hash: 980bf9060e28555fecd9e3462f68ca74007b70f8
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)
I am new to freecad, I am experimenting with FEM.
When I apply the pressure constraint, there is a parameter (surface load), except there is no unit.
I want to know which unit is applied for this parameter.
Thank you.
My apologies for not following this procedure.
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.4 (GitTag)
Build type: Release
Branch: releases/FreeCAD-0-18
Hash: 980bf9060e28555fecd9e3462f68ca74007b70f8
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)
- Attachments
-
- chargement surfacique
- chargement surfacique.png (127.24 KiB) Viewed 1552 times
Last edited by REDAC38 on Tue Aug 18, 2020 11:55 am, edited 2 times in total.
Re: Surface loading
Your first post, welcome to FreeCAD.
Firstly always post your version data in the manner explained in the forum Rules link above the Help forum. This is especially important for FEM which is currently in development and improves regularly.
If you are not using the latest snapshot release of FreeCAD0.19 or the daily PPA version or similar, then you should do so if you want to use FEM, 0.18.4 is too old.
Jim
Firstly always post your version data in the manner explained in the forum Rules link above the Help forum. This is especially important for FEM which is currently in development and improves regularly.
If you are not using the latest snapshot release of FreeCAD0.19 or the daily PPA version or similar, then you should do so if you want to use FEM, 0.18.4 is too old.
Jim
Re: Surface loading
Up please.
Re: Surface loading
As mentioned by jmaustpc you should upgrade to 0.19. The current state of this so called development version is indeed more stable than 18.4. In Addition you can have both versions on your system. Just 7-unzip the 0.19 file and place it in an appropriate folder. Please note that with the default configurations both versions share the same config directory.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Re: Surface loading
As far as i can see you don't use pressure. You are using Force.
I understand that it is more clear if both (pressure and force) have a more equal look and feel. My personal prefference would be the textline as by pressure. But that is @Bernd
It is indeed True that no unit is mentioned it is in Englisch so i want consider this as a translation issueI understand that it is more clear if both (pressure and force) have a more equal look and feel. My personal prefference would be the textline as by pressure. But that is @Bernd
bernd wrote: ping
Re: Surface loading
Hello,
And thank you for your feedback.
Indeed I was wrong, it is indeed a question of force constraint and not pressure constraint.
I see that in both cases on your version 0.19 the units are mentioned.
perfect, the units are well to mention.
I wanted to know how the part went in the case of my bar. the mass (1000N) is distributed over the whole of the bar or occasionally. I would like to simulate the weight of a man standing on the bar.
Thank you all.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22270 (Git)
Build type: Release
Branch: master
Hash: 45d28c2367f5714cf5463b3373979c2a6f2779bf
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)
And thank you for your feedback.
Indeed I was wrong, it is indeed a question of force constraint and not pressure constraint.
I see that in both cases on your version 0.19 the units are mentioned.
perfect, the units are well to mention.
I wanted to know how the part went in the case of my bar. the mass (1000N) is distributed over the whole of the bar or occasionally. I would like to simulate the weight of a man standing on the bar.
Thank you all.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22270 (Git)
Build type: Release
Branch: master
Hash: 45d28c2367f5714cf5463b3373979c2a6f2779bf
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)
- Attachments
-
- répartition du poid.png (156.71 KiB) Viewed 1430 times
Re: Surface loading
Best method i think is creating a second shape (solid is not necessary i think) thats intersect with your shape and then use one of the splitting tools (i'm not sure what works best).
Then you have a option to select a smaller surface where you put the force on.
https://wiki.freecadweb.org/Part_CompSplittingTools
Then you have a option to select a smaller surface where you put the force on.
https://wiki.freecadweb.org/Part_CompSplittingTools
Re: Surface loading
We had a similar discussion about applying boundary conditions on specific 'sub-surfaces' in FEM before but I cant find the post....
This i how I did it with boolean-fragments... simply draw a sketch onto the surface you need to divide and apply a boolean-fragments to your body and the sketch.
This i how I did it with boolean-fragments... simply draw a sketch onto the surface you need to divide and apply a boolean-fragments to your body and the sketch.
- Attachments
-
- Screenshot from 2020-08-20 21-10-57.png (355.97 KiB) Viewed 1360 times
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- Screenshot from 2020-08-20 21-11-16.png (279.45 KiB) Viewed 1360 times
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- FEM body with specific region.FCStd
- (226.33 KiB) Downloaded 28 times
Re: Surface loading
seams all questions have been answered already.
Just for reference. For constraint force the unit has to b N (the input field does not support FreeCAD unit system) and for constraint pressure the unit can be put in by the user. For example MPa, Pa, kPa, N/mm^2 MN/m^2 etc are know units.
Just for reference. For constraint force the unit has to b N (the input field does not support FreeCAD unit system) and for constraint pressure the unit can be put in by the user. For example MPa, Pa, kPa, N/mm^2 MN/m^2 etc are know units.
Re: Surface loading
Thank you, for all your answer, I continue to experience all this.