[pereiraICL]

Hi everyone,

I am trying to make a FEA mesh of a mouse bone. I'm starting with a couple of STL files, corresponding to the outer and inner surface of a mouse tibia (Figure mousetibia.JPG).

I want to build the shaft using blocking mesh and mesh the rest using tets. I guess that in the interface between both types of elements, I should have pyramids as transition elements.

I searched in previous posts for someone with the same problem, but I couldn't find anything.

In the second image (blocking.JPG), I show a quad surface mesh with the stl surfaces of the bone. So how can I fill the space in the rest of the geometry with TETs, having transition elements?

Cheers, guys!

Andre

[brunoc]

Hi Andre,

First, you need to create surfaces for the planes that will separate your hexa and your tetra mesh. That's because you'll have to project the hexa surface elements (quads) onto this plane. Put these two surfaces on a separate part.

Now, save the mesh file (.uns) and close your hexa block/mesh. Create a new tetra using only the regions not previously filled with hexa (you can temporarelly put an ORFN material point inside the hexa region). Generate your tetra mesh as normal, taking care only that the mesh density on the interfaces is similar to the mesh density you had on your hexa mesh.

Once tetra mesh is done, load your hexa mesh back and, when asked, choose 'Merge'. This will not merge both meshes, it will only keep them both loaded. To merge the two meshes, go to the Edit Mesh tab, find the Merge Nodes button (8th from the left) and then pick the Merge Meshes button. Select 'Merge volume meshes', then pick the mesh surface parts with the overlaid meshes (the two surfaces that separate hexa and tetra mesh).

Click Apply and you're done!

Cheers