Hinges between plates/shells

[bernd]

To be honest, i do not get that out of the description from the first post. But yes, that in FEM will be pretty hard.

once we know how to define the hinge in calculix it is just a diligent but routine piece of work mostly done in Python. Furthermore we will need some Name, some Icon a wiki page ... all that kind of stuff ... But step by step. As said first the example. fandaL started to provide somethin.

[user1234]

I mean i have overread that he need a hinge in the middle of the plate.

once we know how to define the hinge in calculix it is just a diligent but routine piece of work mostly done in Python.

I want to try it, since i want to help more. But this will take a while to understand all. Must crawling through the sources.

Greetings
user1234

[bernd]

once we know how to define the hinge in calculix it is just a diligent but routine piece of work mostly done in Python.

I want to try it, since i want to help more. But this will take a while to understand all. Must crawling through the sources.

last FEM object we added was this one ... https://github.com/FreeCAD/FreeCAD/comp ... 282db7c8c6

[thschrader]

Totally correct if you would like to have a hinged support, but Thomas would like to set the hinge between two faces ore between two beams and not on a support.

Yes, I mean hinges between plates, not at he support (which is implemented in FC-FEM).
BTW: perfect

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[cad1234]

Would be great, if the hinged-feature could be integrated in FC-FEM.
Would be very helpfull not only for concrete or steel structures but also for wooden structures (due to the different material properties, depending on the fiber direction)...I think..
found this in ccx manual (2.16):

“For an internal hinge between 1D or 2D elements the nodes must be doubled and connected with MPC’s. The connection between 3D elements and all other elements (1D or 2D) is always hinged”

no experience / not enough knowledge how to handle this

[twangrt]

found this in the ccx manual (2.16)

“For an internal hinge between 1D or 2D elements the nodes must be doubled and connected with MPC’s. The connection between 3D elements and all other elements (1D or 2D) is always hinged”

You beat me to it, was searching around the manual for exactly that.
I'm just wanted to add the MPC-card explanation as well.

6.7.2 Multiple point constraints (MPC)
Multiple point constraints establish a relationship between degrees of freedom in
one or more nodes. In this section, only linear relationships are considered (for
nonlinear relations look at the keyword *MPC and section 9.7).They must be
defined with the keyword *EQUATION before the first step.

I think this is an interesting topic, been thinking about ways of improving the 1D/2D support between Calculix and FreeCAD.

[bernd]

I think this is an interesting topic, been thinking about ways of improving the 1D/2D support between Calculix and FreeCAD.

structural engineer

[bernd]

I tried to make a simplified model ... This is much simpler to play with. But I may made a misstake (because I was to fast in clicking ... ) ... The deformation is quite large (35 cm) ... May be some other could have a look as well ...

concrete_plate_bernd.FCStd

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[balrobs]

I tried to make a simplified model ... This is much simpler to play with. But I may made a misstake (because I was to fast in clicking ... ) ... The deformation is quite large (35 cm) ... May be some other could have a look as well ...

Hi Bernd,
your result seems OK! I get 36cm with my commercial software!

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Large deformation are due to large forces f=60000 kN/(6m*2m)=5000 kN/m2
Cheers

Edit:
PS: in the meantime I learned to compile Freecad on Linux so maybe I can help within this topic by doing some test work

[thschrader]

deformation is quite large (35 cm) ... May be some other could have a look as well ...

Load were far too high.
Did some modifications and comparison with my commercial tool.

concrete_plate_ts.FCStd

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