Issue with Cubit export of mixed element meshes with pyramids
Here's an excerpt from my email to cubit-help@sandia.gov:
I'm getting this worrisome warning from 15.7 and 15.8 when exporting a mesh: Using ExodusII API version 8.03 and DB version 8.03 to export "basic-hemi-B0.gen".
WARNING: The model contains 22 nodes (and their attached elements) that will not be written to the genesis file. This may indicate a problem in element block assignments.
The Exodus summary indeed shows 22 fewer nodes that cubit reports for the volumes, however Exodus reports the same number of elements as cubit does. So it would appear that somehow there are free cubit mesh nodes that are unconnected to any element.
The journal file is basic-hemi-B0.jou
I subsequently sent a tiny example that exhibits the same warning:
brick x 1 y 1 z 0.25
brick x 1 y 1 z 0.25
move volume 2 x 0.25 y 0.25 include_merged
webcut volume 1 tool body 2
delete Body 2
webcut volume 3 with plane yplane offset 0 rotate 45 about z center 0 0 0
imprint volume all
merge volume all
volume 1 size 0.25
mesh volume 1
volume 3 4 size 0.25
volume 3 4 scheme tetmesh
mesh volume 3
mesh volume 4
block 1 add volume all
export mesh "example.gen" overwrite
Only some mixed element meshes with pyramids produce this message when exported, and in some cases where it is, there seems not to be any problem at all. However, in some cases there does seem to be something wrong with the exported file. One possible problem (and I forget now whether I observed this in fact) is that the node list includes nodes that are not referenced by any mesh element. That would certainly create all kinds of problems for Truchas.