Phase-field model (2D) [Unstable]
`````````````````````````````````

static
''''''

:Sources:

.. collapse:: phase_field_notch.cc (click to expand)

.. literalinclude:: examples/c++/phase_field_model/phase_field_notch.cc
:language: c++
:lines: 20-

.. collapse:: material_notch.dat (click to expand)

.. literalinclude:: examples/c++/phase_field_model/material_notch.dat
:language: text

:Location:

``examples/c++/`` `phase_field_model <https://gitlab.com/akantu/akantu/-/blob/master/examples/c++/phase_field_model>`_


`phase_field_notch.cc` shows hot to set a quasi-static fracture simulation with phase-field. The geometry of the solid is a square plate with a notch. The loading is an imposed displacement at the top of the plate (mode I).

.. figure:: examples/python/phase_field_model/images/phasefield-static-geo.svg
:align: center
:width: 50%

Notched plate with boundary conditions and imposed displacement.

In addition, this example shows how to extract clusters delimited by the mesh boundaries and elements with damage values beyond a threshold. This can be useful to extract fragments after crack propagation.

.. figure:: examples/c++/phase_field_model/images/phase_field_clusters.png
:align: center
:width: 90%

Damage field after a few iterations and two clusters (fragments) extracted.