[fjburgosf]

Hello everyone. First of all, I just want to say that English is not my first language, so I apologize in advance for any grammatical errors. My problem is the following:
I have a .stl file of a human neonatal calvaria (upper portion of the skull) which I plan on using for a stress-strain dynamic analysis. After working on this file in another software, I was able to generate a closed mesh of it and another one corresponding to the sutures and fontanels (you can see them below), both made by triangular elements, which I imported as a .inp file (abaqus format) in ICEM17.0. These meshes don’t have holes, bad edges, triangle intersections or overlapping triangles. Hence, I could easily generate a delaunay volume mesh for each part (a volume mesh for the sutures and a volume mesh for the entire skull). Both of these volume meshes are error and almost warnings free and possess good aspect ratio TET elements.

So, what is the problem?
What I need is to obtain a volume mesh of the skull attached where some Tet elements (or other kind, hexa or tet10) are defined as bone elements (like a bone elements set) and the remaining ones correspond to suture elements in the suture regions as the image above. So in total, I need two sets of elements in one volume mesh. I don’t need to define a contact surface between two adjacent meshes at the bone suture bone interface, just a way to define some elements as sutures and others as bone in the volume mesh. What I have tried is to make a non-manifold assembly, where an internal surface (an interface) is generated between the skull bone fronts and the sutures, which defines the margins where the tet elements go from being bone to being suture and vice versa. However, I have failed to correctly make this because I haven’t been able to generate the element sets corresponding to skull elements and suture elements in ICEM and when I try to generate the volume mesh, it generates only 1 volume, with only one set of elements. I also need to clarify that I am working with meshes and not geometries because my raw file is a .stl file with more than 100 thousand surface triangles and I haven’t found a way to convert the input file (the skull above) to a solid geometry.
I have work on this for more than a month and haven’t found a way to make it happen, so I really need assistance. Any help will be highly appreciated. Thank you guys in advance.

Sincerely,

Francisco