[Ticket #4617] Virtual elements

[saso]

just some videos that I think should demonstrate the use of this (or similar) in a commercial tool...

https://www.youtube.com/watch?v=aMyvfqlzCZ4 RBE2, RBE3 and MPC's in NASTRAN (Altair Optistruct)
https://www.youtube.com/watch?v=NoWmXvMYhKg Virtual Bolt in Catia
https://www.youtube.com/watch?v=D9v7FqX9UlQ Virtual Part Explained in Catia
https://www.youtube.com/watch?v=-oL97_OvczM FEA Coupling RBE2 RBE3 3DEXPERIENCE R2022x
https://www.youtube.com/watch?v=aFpWc3yBhq8 Talking Shop with Tony Abbey - Episode 10 - What are 'spider' elements in FEA
https://www.youtube.com/watch?v=r4PUyxlouww How to connect finite element models with Simcenter 3D
https://www.youtube.com/watch?v=wi8KTxTXrz4 Using Simcenter to Model Mechanically Fastened Joints
--- https://apps.dtic.mil/dtic/tr/fulltext/u2/a117342.pdf "Design Methodology for Bonded-Bolted Composite Joints", L. J. Hart-Smith
--- https://www.osti.gov/servlets/purl/929124 "Guideline for Bolted Joint Design and Analysis", Sandia Report SAND2008-0371
--- https://www.boltcouncil.org/files/2ndEditionGuide.pdf "Guide to Design Criteria for Bolted and Riveted Joints", AISC
--- https://ntrs.nasa.gov/api/citations/199 ... 009424.pdf "Fastener Design Manual", NASA-RP-1228
--- https://ntrs.nasa.gov/api/citations/199 ... 012183.pdf "Preloaded Joint Analysis Methodology for Space Flight Systems", NASA-TM-106943
--- https://ntrs.nasa.gov/api/citations/198 ... 001540.pdf "Critical Joints in Large Composite Aircraft Structure", W D Nelson, Bruce Bunin, L. J. Hart-Smith
https://www.predictiveengineering.com/s ... -and-cbush RBE2, RBE3 and CBUSH in NASTRAN (NX Nastran)
--- https://www.predictiveengineering.com/s ... _rev-1.pdf (pdf)

[Pauvres_honteux]

... just some videos ...

Thanks for them examples saso!

[UR_]

Specific use case from a FreeCAD user


https://calculix.discourse.group/t/how- ... omax/656/3

[Pauvres_honteux]

... use case from a FreeCAD user ...

... and directly from the source(Calculix) as well.

Very good sir!

[saso]

Links to topics with updated info about this...
https://forum.freecadweb.org/viewtopic.php?f=18&t=60892
https://forum.freecadweb.org/viewtopic.php?f=18&t=62038

[aerospaceweeb]

To all parties interested, here's a youtube video showing how this piece of script works;
https://youtu.be/zhMpSoyspJA

and here's a script that makes an RBE3 that attaches all of the nodes within a spherical tolerance together.
https://github.com/zchlrnr/FCMesher/blo ... _sphere.py

I made another similar tool that's way simpler to make a bush-spider once I realized that node sets existed and that I could use them to specify lists of nodes more easily.
Here's that piece of caveman-technology.
https://github.com/zchlrnr/FCMesher/com ... beaa9f5156

I think I want to marry these two together as a proof of concept, but I'd still be at a bit of a loss for how to show it.
I'm extremely open to suggestions.

[Pauvres_honteux]

Hmm, as a user I'd like to chose a piece of surface already defined in PartDesign/Part/Surface to be the contact area (e.g. under screw head / threaded piece).
The same goes for lines and points and curves.
I.e. the user creates everything in PartDesign/Part/Surface, then it can be used in FEM for defining meshes/forces.
Additionally one can create that stuff directly in FEM. But the default shall be get the information from PartDesign/Part/Surface.

The benefit of making everything from PartDesign/Part/Surface created stuff is that you programmers then (later) can implement auto-update of the FEM-mesh, when the model is changed/updated. This way us users can play around with different design solutions without the need to manually re-mesh, re-connect and re-define everything, i.e. a big time saver. And time is big money in big companies.

[Pauvres_honteux]

Hi bernd, are you the one working on Virtual elements?
Or will you be working on Virtual elements?