Implemented ccx's CENTRIF label from *DLOAD card

About the development of the FEM module/workbench.

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UR_
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Implemented ccx's CENTRIF label from *DLOAD card

Post by UR_ »

Just implemented centrigual body loads.
Concerning CENTRIF label from ccx's *DLOAD card.

Here we have a not very glamorous example.
Two rotating steel rings at 100 rev per sec.
one is made of steel density 8.0 kg/dm^3, the other is made of Scotty's steel
(same properties as usual but only half density)

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So we have a analytic result to compare ccx' results against.

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Ring unter Zentrifugallast.sm.zip
(1.47 KiB) Downloaded 72 times
UR_
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Re: Implemented ccx's CENTRIF label from *DLOAD card

Post by UR_ »

centrif.FCStd
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Screenshot 005.png
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PR: https://github.com/FreeCAD/FreeCAD/pull/4738

bernd wrote: :bell:
Can you please have a look?
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Re: Implemented ccx's CENTRIF label from *DLOAD card

Post by Jee-Bee »

Nice work!
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Re: Implemented ccx's CENTRIF label from *DLOAD card

Post by bernd »

- download the file from this post
- purge results
- run it
- I get same results

BUT
- clear the mesh
- remesh it without group meshing (which is default FreeCAD pref)
- ccx gives an error ...

- does the mesh have to have group data for the centrif constraint to run proper?
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Re: Implemented ccx's CENTRIF label from *DLOAD card

Post by bernd »

BTW: I set up the example in Python for a unit test. See https://github.com/berndhahnebach/FreeC ... 39e41966bd But it only runs with your Mesh and of course your object names (to match the group names)

If the mesh has no groups ccx gives an error.

Does the example work for you without mesh groups?
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Re: Implemented ccx's CENTRIF label from *DLOAD card

Post by UR_ »

It's only implemented for group meshing.
Screenshot 001.png
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Because it's greyed out and checked, I thought that's the way to go.

Should be faster than sorting out nodes by python, isn't it?
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Re: Implemented ccx's CENTRIF label from *DLOAD card

Post by bernd »

UR_ wrote: Thu Jun 24, 2021 3:25 pm It's only implemented for group meshing.
Screenshot 001.png
Because it's greyed out and checked, I thought that's the way to go.

Should be faster than sorting out nodes by python, isn't it?
it is much much faster than sorting out. That was the reason I did implemented this. But has problems in some circumstances. Thus standard setting is off. Because of the problems I only recommend this for power users like you. But we should make work analysis with this setting to off. All unit tests uses meshes without groups.

The problem is not the use of the groups but the meshing. The problems have happened on the meshing with groups and than the analysis did not run at all.
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Re: Implemented ccx's CENTRIF label from *DLOAD card

Post by bernd »

https://github.com/berndhahnebach/FreeC ... femcentrif

How about this? Should work with and without group data. Would you give it a try?

cheers bernd
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Re: Implemented ccx's CENTRIF label from *DLOAD card

Post by bernd »

Once more I did some heavy history rewriting and squashing. We do have a clean history for this PR ATM. Thus very good documentation for adding mre constraints.

If you would give your ok I would go for a merge.
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Re: Implemented ccx's CENTRIF label from *DLOAD card

Post by bernd »

Added a unit test. The unit test is before all the gui tools and code. The unit test does not need all the gui tools and code.

cheers bernd

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