questions of unstructured grid vtk (legacy formats)

ParaView Support
1

Hi,
I am having an issue when import vtk file (unstructured grid based on legacy format) into ParaView.
I use Abaqus to perform FEA and try to plot outputs in ParaView.
The geometry is like a tunnel (circular excavation at center)
The model has 13440 nodes, 12000 elements C3D8R (8 nodes)
Here is the issue. Please see below.
Surface data representation is a problem. Not sure what was wrong.

Screenshot (51)
Screenshot (51)2746×1326 264 KB

This is what the mesh looks like in Abaqus.
Screenshot (52)
Screenshot (52)1910×888 295 KB

This is a structure in vtk legacy format I used.

vtk DataFile Version 3.0

UNSTRUCTURED_GRID(C3D8R_HEXAHEDRALMESH)
ASCII
DATASET UNSTRUCTURED_GRID
POINTS 13440 double
3. 3. 10. <---- nodal info (x,y,z)
… … … … …
CELLS 12000 108000
8 152 1373 4929 841 1 33 689 78 <---- cell connectivity info
… … … … …
CELL_TYPES 12000 <---- cell type info
12
12
… … … … …

Please find attached vtk file.
TemplateMesh3D_UNSTR.vtk (1.1 MB)
Thank you.

2

It looks like your data file is malformed. I believe the indices in your CELLS array is wrong. It looks like you are indexing points using 1-based indices when VTK uses 0-based indices. So, for example, the CELLS array would start like this:

CELLS 12000 108000
8 151 1372 4928 840 0 32 688 77
… … … … …

I note that when I change the indices of the first cell like this, the first cell looks correct when loaded in ParaView.