3D Tetra Elements not showing in LS-PrePost/DYNA

Altair Forum User

Hello,

I imported my geometry into HyperMesh and used automesh to generate quads on the surface.
I then used volume tetra to generate 3D tetras and then deleted the 2D elements on the surface.
When I export my model to DYNA keyword file and open it in LS-PrePost, it is missing the extra pyramid elements at the surface.

 

E.g. 2D view in HyperMesh:
 

View of surface using mask option in HyperMesh.

 

Surface in LS-PrePost:


Any thoughts on why this is? How can I retain the elements at the surface?

Thanks,

Petros

tinh

Shift F6 split quads into trias before tetramesh

Q.Nguyen-Dai

Pyramid elements are supported in LS-DYNA, but Hypermesh can not export them to DYNA key output.

I have to play with template to add this element type.

Altair Forum User

Thanks Tinh, I don't want trias at the surface though.

Q.Nguyen-Dai

Altair Forum User said:

Thanks Tinh, I don't want trias at the surface though.

 

You don't want trias at surface and you can not make pyramid for your LS-DYNA. So what do you do now then?

 

tinh

Maybe he want to keep quads as a cover comp

@PetrosYou can split pyramids into tetras by panel 3d>split>solid elements 

switch to 'split into tetras'

Altair Forum User

Thank you both for your suggestions.

Q.Nguyen-Dai

Keep 'quads' at external faces and make 'tet' in internal volume? That does not make sense from point of view of FEA !!!

 

tinh

Yeah, it seems to be not continous!

Don't understand