Modeling B: in dimension 3
===============================

In this modeling, we consider the structure in 3D.


Characteristics of the mesh
----------------------------

The structure is modelled by a regular mesh composed of :math:`2\mathrm{\times }5\mathrm{\times }5` HEXA8, respectively along the :math:`x,y,z` [:ref:`Figure 3.1-3.1-a <Ref183579631>`] axes. The interface goes through the middle of the elements.


.. image:: images/1000000000000584000002CA1E955E581571C525.png
    :width: 6.3374in
    :height: 3.2043in


.. _RefImage_1000000000000584000002CA1E955E581571C525.png:


.. _Ref183579631:

**Figure 3.1‑** 3.1-a **: 3d mesh**


Tested features
-----------------------

We test the application of Neumann conditions via the AFFE_CHAR_MECA and AFFE_CHAR_MECA_F commands on a non-meshed interface with X- FEM.

This imposition is done using the FISSURE keyword from the PRES_REP operand, because the interface is not a group of elements.

We test the application of a constant pressure using a real and then using a space function such as :math:`p\mathrm{=}y\mathrm{\times }20000\mathit{Pa}` (the crack is in :math:`y\mathrm{=}0.5` which is equivalent to applying a constant load).


Tested sizes and results
------------------------------

The displacement values are tested after convergence of the iterations of the operator STAT_NON_LINE.


.. csv-table::

    "**Identification**", "**Reference**"
    ":math:`\mathit{DZ}` for all nodes just below the interface", "-5,00E-7"
    ":math:`\mathit{DZ}` for all nodes just above the interface", "5,00E-7"


To test all the nodes at once, we test the minimum and the maximum of the column.