Importing CAD via UMESH failed

Geometry and Materials
1

Versions

Please provide the used software versions.

FLUKA:4.5.2
Flair:3.4-0

Description

Dear Experts,

I have carefully read the relevant forum posts about importing CAD models via UMESH. Following the suggested methods, I successfully generated and imported the snowman.abaq example.

However, I encountered an issue when trying to import my own model built in SolidWorks. I created a simple geometry consisting of a room containing a target, exported it as a .3mf file, and used FLUKA_mesh_fix.py to generate the .abaq file.

After importing it to FLUKA, I found that although three regions were successfully generated as defined, only the largest one is visible in the Geometr

y. Additionally, I tried running a simulation; it ran without crashing, but the particles I set up were not scored/tallied as expected. I am quite confused about which step might be causing this problem. I would really appreciate your guidance.

The relevant .inp file, .3mf file, and the original SolidWorks file are attached below.

Thank you very much for your help.

Input files

UmeshTest.zip (131.7 KB)

3

Dear @22111140001,

The issue is that .3MF or .STL CAD formats do not work well with hollow parts (it’s mechanically hard to manufacture hollow parts), they usually describe only a single surface (and not two). Gmsh default meshing GEO algorithm, in this case, considers only an outer surface.

You should use an OCC route, added recently to the script, with .STEP format by executing the script with --occ argument.
Also, you could simply split bodies so there are no hollow parts.

Here I changed reg_1 material, so it’s also visible in 3D

image
image1664×792 144 KB

Best regards,
Volodymyr

room.zip (5.5 KB)

4

Dear Volodymyr,

Thank you very much for your prompt response. I have attempted both approaches, and the issue is now fully resolved.