Hinges between plates/shells

[user1234]

Yes. I want avoid github itself as a can. But at first my local branch should work anyway. Then make the diffs.

Thanks!

Greetings
user1234

[johnwang]

I tried also variant with *MPC cards. It triggered nonlinear calculation

http://www.feacluster.com/CalculiX/ccx_ ... de278.html

This Bernd provided link says "A *MPC card automatically triggers the NLGEOM parameter, i.e. a geometrically nonlinear calculation is performed, except if the MPC is a mean rotation MPC."

For mean rotation MPC, you could see example here http://www.feacluster.com/CalculiX/ccx_ ... de353.html

[johnwang]

Code: Select all

** BINDING DOF OF DUPLICATED NODES
** NODES 1 AND 40
*EQUATION
2
1, 1, 1, 40, 1, -1

MPC is equivalent to this EQUATION. For Nastran95:

mpc.jpg (14.09 KiB) Viewed 1999 times

G1=point 1, C1=1 (x displacement), A1=1.0
G2=point 40,C2=1 (x displacement),A2= - 1.0

[johnwang]

Here is a working version with MPC as hinge for Mystran.

HingeMPC.dat.txt

(23.04 KiB) Downloaded 36 times

[johnwang]

Here is a working version with RBE2 as hinge for Mystran. The result is 8.5, same as the commercial one.

Does Calculix has RBE2? Nastran95 is CRBE2.

HingeREB2.dat.txt

(22.62 KiB) Downloaded 48 times

[thschrader]

Hi John, thanks for your work.
There is a question in the german forum about Frame3DD.
Maybe you can answer Lauries question. Dont hesitate to write in english.
https://forum.freecadweb.org/viewtopic. ... 9&start=50

Frame3D.JPG (47.03 KiB) Viewed 1829 times

[johnwang]

There is a question in the german forum about Frame3DD.

I answered one of his question.
https://forum.freecadweb.org/viewtopic. ... 20#p513172

[twangrt]

Is there anyone already pursuing this?

Got a window of opportunity and was thinking of trying to give it a serious go.

Tough I'm been poking around the code and it seems like a more complicated task than I initially thought. But you can't blame a guy for trying.

[johnwang]

Is there anyone already pursuing this?

Got a window of opportunity and was thinking of trying to give it a serious go.

Tough I'm been poking around the code and it seems like a more complicated task than I initially thought. But you can't blame a guy for trying.

I have uploaded a working version with MPC as hinge for Mystran.

For Calculix, you need to understand the 'mean rotation MPC' I mentioned.

[bernd]

The only working solution for Calculix we have found so far is by changing the original mesh, which is not something I am happy with ... https://forum.freecadweb.org/viewtopic. ... 20#p516277

It would be cool if we would found something without changing the mesh and without triggering nonlinear analysis.