Read blocked Ansys MAPDL archive files written from MAPDL using CDWRITE.

This is effectively pymapdl-reader without the binary reader. It's been isolated to allow greater flexibility in development.

Installation through pip:

pip install mapdl-archive

ANSYS archive files containing solid elements (both legacy and modern), can be loaded using Archive and then converted to a VTK object.

from mapdl_archive import Archive, examples

# Sample *.cdb
filename = examples.hexarchivefile

# Read ansys archive file
archive = Archive(filename)

# Print raw data from cdb
for key in archive.raw:
   print("%s : %s" % (key, archive.raw[key]))

# Create an unstructured grid from the raw data and plot it
grid = archive.parse_vtk(force_linear=True)
grid.plot(color='w', show_edges=True)

# write this as a vtk xml file
grid.save('hex.vtu')

# or as a vtk binary
grid.save('hex.vtk')

You can then load this vtk file using PyVista or VTK.

import pyvista as pv
grid = pv.UnstructuredGrid('hex.vtu')
grid.plot()

MAPDL archive *.cdb and *.dat files containing elements (both legacy and modern) can be loaded using Archive and then converted to a vtk object:

import mapdl_archive
from mapdl_archive import examples

# Read a sample archive file
archive = mapdl_archive.Archive(examples.hexarchivefile)

# Print various raw data from cdb
print(archive.nnum, archive.nodes)

# access a vtk unstructured grid from the raw data and plot it
grid = archive.grid
archive.plot(color='w', show_edges=True)

You can also optionally read in any stored parameters within the archive file by enabling the read_parameters parameter.

import mapdl_archive
archive = mapdl_archive.Archive('mesh.cdb', read_parameters=True)

# parameters are stored as a dictionary
archive.parameters

Unstructured grids generated using VTK can be converted to ANSYS APDL archive files and loaded into any version of ANSYS using mapdl_archive.save_as_archive in Python followed by CDREAD in MAPDL. The following example using the built-in archive file demonstrates this capability.

import pyvista as pv
from pyvista import examples
import mapdl_archive

# load in a vtk unstructured grid
grid = pv.UnstructuredGrid(examples.hexbeamfile)
script_filename = '/tmp/grid.cdb'
mapdl_archive.save_as_archive(script_filename, grid)

# Optionally read in archive in PyMAPDL and generate cell shape
# quality report
from ansys.mapdl.core import launch_mapdl
mapdl = launch_mapdl()
mapdl.cdread('db', script_filename)
mapdl.prep7()
mapdl.shpp('SUMM')

Resulting ANSYS quality report:

------------------------------------------------------------------------------
           <<<<<<          SHAPE TESTING SUMMARY           >>>>>>
           <<<<<<        FOR ALL SELECTED ELEMENTS         >>>>>>
------------------------------------------------------------------------------
                   --------------------------------------
                   |  Element count        40 SOLID185  |
                   --------------------------------------

 Test                Number tested  Warning count  Error count    Warn+Err %
 ----                -------------  -------------  -----------    ----------
 Aspect Ratio                 40              0             0         0.00 %
 Parallel Deviation           40              0             0         0.00 %
 Maximum Angle                40              0             0         0.00 %
 Jacobian Ratio               40              0             0         0.00 %
 Warping Factor               40              0             0         0.00 %

 Any                          40              0             0         0.00 %
------------------------------------------------------------------------------

At the moment, only solid elements are supported by the save_as_archive function, to include:

• vtk.VTK_TETRA
• vtk.VTK_QUADRATIC_TETRA
• vtk.VTK_PYRAMID
• vtk.VTK_QUADRATIC_PYRAMID
• vtk.VTK_WEDGE
• vtk.VTK_QUADRATIC_WEDGE
• vtk.VTK_HEXAHEDRON
• vtk.VTK_QUADRATIC_HEXAHEDRON

Linear element types will be written as SOLID185, quadratic elements will be written as SOLID186, except for quadratic tetrahedrals, which will be written as SOLID187.

The mapdl-archive library is licensed under the MIT license.