Virtual elements

[parnasist3]

Hi mkraska, I'm looking for an example of how to create virtual elements. You know the ones we use instead of screws or to place a force/torque a distance away from the calculated object. I saw a guy in the FreeCAD forum asking for it and sure enough, I couldn't find how to it either.
Any chance you could create a few examples on how to make them?

[oldninja]

Do you mean like RBE2/RBE3s?
For RBE2 | *COUPLING and *KINEMATIC; or *KINEMATIC COUPLING
For RBE3 | *COUPLING and *DISTRIBUTING; or DCOUP3D and *DISTRIBUTING COUPLING
See those commands in http://www.dhondt.de/ccx_2.17.pdf

[parnasist3]

Hi oldninja, please have a look at Virtual element types and mark on the pictures which node correspond to what denomination you typed here above, e.g.:

RBE2 | *COUPLING and *KINEMATIC; or *KINEMATIC COUPLING = see picture xx at position yy ... and so on ...
RBE3 | *COUPLING and *DISTRIBUTING; or DCOUP3D and *DISTRIBUTING COUPLING = see picture aa at position bb ... and so on ...

[oldninja]

Hi parnasist3, sorry about the use of the RBE2/RBE3 terminology - this terminology is used in NASTRAN and other codes.
It depends on what you need. If you need a rigid connection, then use the kinematic coupling - see CalculiX-Examples/Test/Joints/README.md. If you need to distribute the loads between the tied nodes, then use the distributed coupling - see CalculiX-Examples/Linear/BiaxBending/.
Hope this helps!

[parnasist3]

Hi oldninja, I'm sorry but I can not wrap my head around the terminology versus the pictures.
Any chance you can make a few examples with respect to the pictures?