I start in forum posting a brief (and maybe basic) question that drives my crazy since last week.
I´m trying to obtain the displacement of the center of gravity (COG) of a model.
This means, an undeformed model has a certain COG, whose coordinated couId be obtained via the .f06 file (for sure there should be a simplier way directly in FEMAP).
The goal is to obtain the COG of the deformed model after running it with NX Nastran.
Thank you very much in advance for your help.
Solved! Go to Solution.
If you create a node attached to the mesh at the COG, you can simply extract the displacements of that node.
If you need to locate the COG of the mesh, use the command, Tools > Mesh Properties > Mass Properties.
Hi Chip Fricke,
thanks a lot for the quick response.
I´ve thought about that, but the issue comes on how to attach the COG node to the mesh without modifying the stiffness of the structure but capturing properly the COG displacement. (a massive weighted RBE3 doesn´t seems as a good solution to me)
Thanks a lot for your help
(and tip! Mass prop. command seems really useful)
Another option is to put FEMAP to work: deform your model in FEMAP using the macro Custom Tools > PostProcessing > Nodes move by Deform, then make FEMAP recompute the CoG through Tools > Mass Properties > Mesh Properties.
But a RBE3 that takes your entire model should be fine as well.
Compare both methods and see what comes out!
In my opinion the simplest method is the following:
thanks a lot for your quick and precise response.
However, I don´t fully agree (or understand) the suggested methodology. As far as I can read. This mill modify the original mesh, translating a single node (the closest) to the COG.
As the model is modified, once runned, it will result in a different deformed than expected. Of course, these variations depends of the geometry.
As always, thanks you very much for your time and efford. (80% of my FEMAP knowledge comes from your blog and youtube channel).