Structured split of quads into triangular elements

[abdiel]

Good day all,

I am able to split my quads into 4 crossing triangles using the option: utilities/preferences/Meshing->Symmetrical Structures. And it works perfectly.
The issue is, that when I run my anal sys (using PFEM) even at time 0.0 (no deformations or whatsoever) the triangles immediately loose their arrangement. That is, I cannot keep them as 4 diagonally crossing triangles composing the geometry, but rather they change their pattern and loose this configuration.

Do somebody has any clue on how to improve this, or what could be a reason?

Thanks a lot in advance,
Abdiel

[escolano]

Read the answer of this: http://www.gidhome.com/forum/viewtopic.php?f=6&t=3661

I don't understand what do you mean by 'the triangles loose their arrangement'.
How is the mesh changing after it has been generated?

A comment: maybe you are creating a mesh of quadrilaterals, and then manually splitting in triangles with
Mesh->Edit mesh->Split elements
Edit a mesh is not the recommended way, it is better to assign this data to the geometry and generate the mesh, without any manual modification.

[abdiel]

Thank u very much for the prompt reply. By "loosing their arrangement" I meant that the triangles where not kept in this diagonal form and took a random configuration. As if I was not splitting the quads into tri at all.

You are right, I am editing the mesh in such a way. I will take the corrections.

Thanks again,
Abdiel