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Mirror an entire FEA model (including underlying geometry)

Genius
Genius

What are the best ways to do this? I want to maintain mesh-geom associativity, but that is not critical because I can remesh.

 

The tools I know make a copy of the thing to be mirrored, rather than just mirroring it.

 

I also have boundary conditions, loads, etc. on both geometry and nodes, which I would like to preserve.

6 REPLIES

Re: Mirror an entire FEA model (including underlying geometry)

Phenom
Phenom
I suggest:
(a) Save the model, then save a 2nd identical copy and do the following on the 2nd copy;
(b) Modify -> Scale -> Solid ... select the scale (reflection) point, and use -1 in the appropriate direction to reflect all the geometry, If you have other separate geometry (eg. non-parasolid curves for beam mesh, non-parasolid points for Mesh Point on surface etc), then also scale these by -1 to reflect these.
(c) Modify -> Scale -> Element by -1 in one of the directions to do the same with all the elements.

You now have a model which is completely reflected and is fully associated, loaded, constrained etc.
(d) Save the reflected model.
(e) Also open the original model in the same Femap session and use File | Merge to combine the original model with its reflection. Note that you will have to choose how to offset the ids of all the entity types you wish to merge.

Re: Mirror an entire FEA model (including underlying geometry)

Genius
Genius

Sounds good, but I don't understand the need for a secondary merge operation. Can you please elaborate?

Re: Mirror an entire FEA model (including underlying geometry)

Phenom
Phenom
I had interpreted that you had built a half model and wanted the original half and the reflected half all together to create a whole model. If you only wanted the model reflected, and didn't also need it together with the original "half", then your job is easier and you can forget the merge.

Re: Mirror an entire FEA model (including underlying geometry)

Genius
Genius

Perfect. I had built the model based on accidentally mirrored geometry, so it was complete.

Re: Mirror an entire FEA model (including underlying geometry)

Experimenter
Experimenter

I tried this, however this gives me a negative volume.

Re: Mirror an entire FEA model (including underlying geometry)

Phenom
Phenom
Interesting... I hadn't noticed that before!
I am fairly sure if you do a Tools -> Check -> Element Quality (even if you choose no quality checks) and tick the Check / Fixup Invalid Elements, then that problem disappears.