Unsuccessful meshing with hexahedral elements

Coreform Cubit Meshing
#1

Dear forum members,

I am a beginner Trelis user and have run into a problem while trying to mesh my geometry using hexahedral elements (see the attached file test.cub). I have read the available resources on making volumes sweepeable, but nevertheless I am still unable to circumvent the problem. I would appreciate greatly any help in the matter.

My geometry is shown in letter_box.jpg. Most of the volume is already meshed. The problematic section is at the top of the geometry. The floor surface has an irregular mesh, shown in letter_box_1.jpg. When I specify the two opposite vertical surfaces of the problematic volume for sweeping, I receive the error:

Trelis>mesh volume 33
ERROR:
Linking surface 316’s mesh is not regular.
Matching intervals successful.
Meshing back@top (Volume 33)
ERROR:
Existing mesh on surface 316 (Surface 316) is not regular!
Delete mesh and change scheme to map or submap.
ERROR:
back@top (Volume 33) meshing unsuccessful.

When I change to map or submap, I get the following error:

Trelis>mesh volume 33
WARNING: Unable to pick mapping corners for Surface 322 (surface 322),
incompatible intervals are hard set on its curves.
ERROR:
Matching intervals <<< UNSUCCESSFUL >>>

ERROR:
Interval assignment unsuccessful.

Could somebody help me resolve this issue?
Many thanks,

Marek
test.cub (1.99 MB)
letter_box_1.jpg
letter_box.jpg

#2

Marek,

You need to decompose the geometry a little bit more to make everything sweepable. Try the following approach:

open “test.cub”
delete mesh
unmerge all
webcut body 33 31 5 with sheet extended from surface 284
create vertex on curve 542 fraction 0.5
list vert 314
webcut body 5 33 31 with plane yplane offset -0.69 preview
webcut body 5 33 31 with plane yplane offset -0.69
delete vertex all
imprint all
merge all
vol all scheme auto
mesh vol all

–Corey

#3

Your help is very much appreciated!
Many thanks,

–Marek