mapdl-archive

###################### MAPDL Archive Reader ######################

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

This is effectively pymapdl-reader <https://github.com/ansys/pymapdl-reader>_ without the binary reader. It's been isolated to allow greater flexibility in development.

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Installation

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Installation through pip:

.. code::

pip install mapdl-archive

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Examples

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Load and Plot an MAPDL Archive File

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

.. code:: python

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')

.. figure:: https://github.com/akaszynski/mapdl-archive/blob/main/doc/hexbeam_small.png :alt: Hexahedral beam

You can then load this vtk file using PyVista <https://docs.pyvista.org/version/stable/>_ or VTK <https://vtk.org/>_.

.. code:: python

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

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Reading ANSYS Archives

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

.. code:: python

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.

.. code:: python

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

parameters are stored as a dictionary

archive.parameters

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Writing MAPDL Archives

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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.

.. code:: python

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:

.. code::

---

          <<<<<<          SHAPE TESTING SUMMARY           >>>>>>
          <<<<<<        FOR ALL SELECTED ELEMENTS         >>>>>>

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                  --------------------------------------
                  |  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 %

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Supported Elements

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.

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License and Acknowledgments

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