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.
Hinges between plates/shells
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Re: Hinges between plates/shells
Re: Hinges between plates/shells
I mean i have overread that he need a hinge in the middle of the plate.
Greetings
user1234
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
Re: Hinges between plates/shells
last FEM object we added was this one ... https://github.com/FreeCAD/FreeCAD/comp ... 282db7c8c6
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Re: Hinges between plates/shells
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
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
Re: Hinges between plates/shells
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.
I think this is an interesting topic, been thinking about ways of improving the 1D/2D support between Calculix and FreeCAD.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.
Re: Hinges between plates/shells
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 ...
Re: Hinges between plates/shells
Hi Bernd,
your result seems OK! I get 36cm with my commercial software! 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
Last edited by balrobs on Mon Jul 12, 2021 2:16 pm, edited 1 time in total.
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