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Published 20 hours ago • verified publisher icon calculix

Virtual elements

Open parnasist3 opened this issue 4 years ago • 4 comments

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?

parnasist3 avatar Sep 12 '20 11:09 parnasist3

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

oldninja avatar Sep 12 '20 19:09 oldninja

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 ...

parnasist3 avatar Sep 14 '20 09:09 parnasist3

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!

oldninja avatar Sep 14 '20 17:09 oldninja

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?

parnasist3 avatar Sep 16 '20 17:09 parnasist3