Sheet unite? NX 6.0.1.5

[jenda224]

I solve problem with unite of the sheet part for advance simulation. (in Ideas is it easy). Is it any way to unite sheet part? Thanks.

ps:sorry for my english

 

[jerry1423]

I do not know about NX6, but in NX5 and before you would use SEW.

If you have trouble finding the it in the menu the go to Help (pull-down) > command finder

 

[jenda224]

Yes, for normal modeling with sheet it works. But for 2D mesh it doesn't work. In Ideas it was possible to unite sheet features, but in NX it isn't possible. Sew dosn't work as unite, unfortunately.

 

[potrero]

jenda224, it looks like you've got something like a rib meeting a face. My understanding is that there are at least two main ways to handle this situation in NX6 Advanced Simulation. Actually I just posted a question a couple days ago on this topic... see my post at thread561-235827

So, check out either:

Insert > Model Cleanup > Stitch Edge > Manual Face to Edge

or

Insert > Mesh > 1D Connection > Edge to Face

I'm still unsure as to what the * best * approach is. Hopefully this helps.

 

[jenda224]

potrero:

Thanks, but for my example it doesn't work correctly. For good results is necessary to rightly divide the face, but is it hard work on bigest assemblies. I hope that exist an one button function for unite.

 

[potrero]

can you post your example (fem and part)?

 

[NXMold]

Try "trim and extend" using type "make corner"
Its under Insert, trim

Not sure if thats what you are looking for, but I use it a lot while surfacing.

NX 5.0.3.2 / 6.0.1.5 MoldWizard

 

[jenda224]

This is my example. About the 1D conection, I am afraid the 1D elements and their correctness (results correctness). On the bigest assemblies make 1D elements problems (time, results credibility, etc.)

 

[potrero]

jenda224,
I just did the Insert > Model Cleanup > Stitch Edge > Manual Face to Edge approach, and it seemed to have worked just fine. Attached is a picture showing the output of a Check for Free Edges, showing that the edge meeting the face is NOT free anymore. You can also see that as a result, the meshes are coincident at their intersection.

Did you really try this approach and it didn't work for you?

 

[JohnRBaker]

OK, You can't sew or even 'unite' (in NX) two sheets which form a 'T' shape as that would result in a non-manifold body, which NX does not support as part of the regular modeling tasks. However, in the CAE modules, when creating meshes, there are ways to match the mesh of one surface to the mesh of another that forms a 'T' so that the results is AS IF the two surfaces were actually a single body, but it's done during the task of meshing, NOT as part of the part model.

Now, I'm not a Simulation expert, but there are routines for refining meshes which can force the nodes of the elements on one face to align with nodes of the elements on an adjoining face. This is what you should be looking at in situations like this. After all, it's not the geometric model which is being used when solving a simulation problem, but rather the network of elements which REPRESENTS the geometric model which is being used. Getting that right is what counts.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.

 

[potrero]

Here's the modified FEM file (after Stitching Edge and re-meshing).

 

[jenda224]

potrero,
yes, for this easy assembly it work. But for assembly on jpg file is it big problem. How I see, it isn't any another chance how to make it (only time demand Stitch Edge).
Thank you so much for help.

 

[potrero]

jenda224,
Ahh yes. I share your exact frustration. Stitch Edge is only really useful for (a) small parts and/or (b) parts which don't require any upstream changes. For large parts that have any upstream design changes, Stitch Edge gets (a) extremely time consuming and (b) unstable to use.

I'm not really sure what the "best" way to model ribs like this is, in NX Advanced Sim; what I've found is that using RBE's (ie: the 1D Connection, Edge-to-Face approach) is more robust to design changes than Stitch Edge.

Can you explain in more detail the "unite" function you have mentioned, in I-DEAS?

I do think that this is an area where the Advanced Simulation FEM preprocessor could be greatly improved.

 

[jenda224]

I saw the function in Ideas by my friend. It is very easy, its boolean operations. As at work with solid models (unite, subtract, intersect). For 2D meshing is Ideas unfortunately better. :-(