Create complex object with shell in CAE

[ninguno]

I've imported an irregular shape (bone) using IGES, and finally managed to create a solvable model in CAE.

What I'd like to do now is to have the same object with a .5 mm shell around the border, with different material properties than the interior.

What's the best way to do this? (am a newbie)

Should I create two instances of the part, one a shell and one a solid? How do I get them to interact properly in this case?

 

[corus]

In the part module you can create a shell from solid. Save this as a different part name and then assemble the shell and solid parts together.

corus

http://www.corusresearch.com

 

[ninguno]

Thank you for the reply.

Is it best to use a contact constraint through assembly, or use an interaction?

I'm just sort of crossing my fingers and hoping that it treats the dimensions correctly-- That is, the shell is on the outside of each object and that it doesn't mess up the geometry between the multiple objects-with-shells.

 

[ninguno]

I can get the shell and volume to generate and apparently interact, but I'm not sure whether it's behaving properly.

In I-DEAS I noticed you can take your geometry, build a shell mesh, then build a volume mesh using the same surface nodes. That way, the two are inherently connected.

Is there a way to do the same in CAE, or is that what the interaction contstraints are for?

 

[DickButkus]

/CAE can create a shell around a volume much easier than you can in Ideas or Patran. Simply go to the properties module and define a skin. All you have to do is pick on the surfaces that you wish to have the shell and assign shell properties to it.

It's usually helpful to define the material and the shell section before defining the skin, but, I believe you can pick the skin first if you wish.

/CAE will automatically generate the elements on the surface that is compatible with whatever solid element you choose. This mesh is generated automatically when you create your solid mesh - there is no need to generate this mesh seperately or mess around with checking for coincidentr nodes. Any time you update the solid mesh the skin will be automatically updated as well.

I hope this helps!

 

[ninguno]

Trying the method using a separate shell and solid method, it seems to get a little bit wonky when I try to mesh for some reason.

The objects I'm meshing are two vertebrae, each have a shell and an inside, and then a disc that lies between the two. When I leave the shell out the disc meshes fine, but when I add it so I have 5 objects, it starts to mesh strangely. In this setup, I have each shell tied to its respective vertebral inside, and then the disc tied to the two shells. Is that the wrong way?

kf9ri: I toyed around in the properties module. What I tried was this:

Created a material for the shell.
Created a section, either a shell or a membrane.

But when I go to try to assign that section, I select my solid object and it only brings up the solid sections I have created, not the membrane or shell. Or is there a separate skin option that I'm missing?

Thanks!

 

[DickButkus]

Go to the property module. Across the main menu (on top) you'll see "Skin". When you hit this you'll have the option to open a skin manager or to just create the skin. Hit create, give it a name, and start selecting faces that you want to create the skin on.

Good Luck!

 

[ninguno]

cool, thanks. this looks promising.

for some reason, my object won't mesh anymore, (I can even re-load an object that successfully meshed, delete the mesh and re-try and no go) but this looks like what I want.