Creating a hollow shell (constant wall thickness) from an STL of a reticulated foam structure

[MariaReji]

Hi all,
I am working with an STL of a reticulated foam structure and need to give the surface a uniform wall thickness d, then remove the interior to leave a hollow shell. I want to mesh the wall thickness in Cubit.

1. Approach 1 : Inward Offset

   create body offset from body 1 distance -d
set developer commands on
subtract volume 2 from volume 1
volume 1 scheme tetmesh
mesh volume 1

   This works, but many of the struts have narrow, sharp cross-sections. Wherever a strut’s cross-section is narrower than twice the offset distance, the inward-offset surface crosses each other.

2. Approach 2 : Outward Offset

   create body offset from body 1 distance d
set developer commands on
subtract volume 1 from volume 2
volume 2 scheme tetmesh
mesh volume 2

   This produces self-intersecting facets. Reducing the offset distance eliminates this, but only at a thickness far smaller than the physical wall thickness actually needed.

   Is there a recommended way in Cubit to generate a hollow, constant-thickness shell from a reticulated foam geometry like this without running into self-intersection issues?

   
   

[Norbert_Hofbauer]

Hi @MariaReji,

can you share your geometry please?

[MariaReji]

cylindrical_foam.stl.zip (1.3 MB)