Moving Coordinate System in Multi-Body Analysis
Hi everyone,
in a multi-Body Analysis, I want to apply a force which is always to stay normal to a surface (i.e. it should maintain its orientation with regard to the applied node). I made a test model to see how I can achieve this (see attached). I would expect that the Body rotates endlessly when the force moves with the Body.
Here is what I tried:
- Define the MBFRC with three nodes of the rigid Body on which it is applied --> not working, the force is only active in the global x-axis direction
- Use a vector (again, defined with three nodes of the rotating body) as an intermediate --> not working
- Use a local coordinate System (tried all CORDxR Systems) --> not working
The help states that CORD1R 'moves with GRID points defining the system' in a geometric nonlinear analysis. This does not seem to apply to multi-Body Dynamics Analysis (see attached example). The coordinate System stays static in the Simulation. The MBFRC doesn't even respect the x-axis direction of the local coordinate System, as the Body rotates in the other direction.
I can't get it to work and any help would be greatly appreciated /emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' />
edit: Sorry, I forgot: I use Optistruct.
Answers
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Hello Cristian
You have to supply G4 field
G4 point to the body so the system will rotate with body
if G4 is blank, the system attached to GROUND
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tinh, you are amazing
/emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' /> Thank you!
Now, how do I get this to work with an MBFRCC force? The help file states that MBFRCC also has a G4 field but it is not in the card anymore after changing the load type to MBFRCC
It's working, however, when manually entering the G4 entry in the .fem-file. I just can't permanently enter it in the card in Hypermesh.
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Just FYI, I solved the problem by deleting the force and moving the entire entry to BULK_UNSUPPORTED_CARDS and adding the G4 field. The force is sadly no longer visible in Hypermesh, but the MBFRCC acts properly in the simulation.
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Did you use HM12?
upgrade version to HM13/14 then you can enter G4 in MBFRCC card
I can fix HM12 OS template to input the field, but everyone uses it no longer
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I am on HM 13.0.
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