*TIE constraint for ccx (aka "bonding faces")

[UR_]

I implemented several shown *TIE constrain.

discussed e.g. here: https://forum.freecadweb.org/viewtopic. ... ie#p337254

Screenshot 001.png (130.98 KiB) Viewed 1646 times

ConeTiedWelding-stripped.FCStd

(20.88 KiB) Downloaded 49 times

source could be found here: https://github.com/UR-0/FreeCAD/commits ... straintTie

code works so far but isn't tested exhaustive.

Please can you have look.


So far two questions arose:

- Fem\femtools\ccxtools.py line 292

Code: Select all

self.tie_constraints = self._get_several_member("Fem::ConstraintPython")

would this collide, if Fem::ConstraintPython is used several times per analysis?


- plausibility checks aren't implemented ATM:

AFAIK,
only two faces per constrain are allowed by ccx,
only volume elements are allowed.

I guess it should be done in def accept from Fem\femguiobjects\_ViewProviderFemConstraintTie.py
or is there another preferred place?

[HoWil]

Hi UR_ your link to "discussed e.g. here: " goes to the attached image. Can you please update it.
BTW: Does this mean the mesh is somehow bend to tie the notes together and solved afterwards?

[bernd]

cool, I will have a look. Just a question, does ccx not support tie of edges (Shell meshes) and vertexes (Line meshes) or did you not implement it?

[UR_]

... does ccx not support tie of edges (Shell meshes) and vertexes (Line meshes) ...

Guido wrote http://www.dhondt.de/ccx_2.16.pdf page 550

8.118 *TIE
Keyword type: model definition
This option is used to tie two surfaces. It can only be used with 3-dimensional
elements (no plane stress, plane strain, axisymmetric, beam or shell elements).
.
.
.

[bernd]

ahh ok ...

rebased branch ... https://github.com/berndhahnebach/FreeC ... its/femtie

[bernd]

I am code formating commit history

thus I did some git history rewritting. Furthermore i would like to split the tie commit in App and Gui.

[bernd]

deleting the space in contact input file writer broke the unit test. This is one reason for separating all changes ... https://github.com/berndhahnebach/FreeC ... 2afb99483b

how about merging the icons and contact space commit into master? OK for you?

BTW the new tie object needs some unit test adaption too for object creation and object type tests ... https://github.com/FreeCAD/FreeCAD/blob ... _object.py

[bernd]

Furthermore i would like to split the tie commit in App and Gui.

done

[UR_]

BTW the new tie object needs some unit test adaption too for object creation and object type tests ...

Needed changes to src/Mod/Fem/femtest/app/test_object.py can be found here:

https://github.com/UR-0/FreeCAD/commit/ ... 81afe05e18

Please let me know, if you need something else.



BTW,

I guess it should be done in def accept from Fem\femguiobjects\_ViewProviderFemConstraintTie.py
or is there another preferred place?

Have you any comments on this?

[bernd]

added the example, would you give it a try ...

Code: Select all

from femexamples.manager import *
doc = run_constraint_tie()

BTW,

I guess it should be done in def accept from Fem\femguiobjects\_ViewProviderFemConstraintTie.py
or is there another preferred place?

Have you any comments on this?

yes but step by step ... sorry for the delay in this regard ...