P modeling
==============

Validation of the implementation of law CZM_TAC_MIX in formulation X- FEM. We are testing the opening mode. This modeling is an adaptation to X- FEM of the :math:`G` modeling.


Characteristics of modeling
-----------------------------------

The line of discontinuity is modelled by an X- FEM interface, which is introduced into the model by the DEFI_FISS_XFEM operator, with TYPE_DISCONTINUITE =' INTERFACE '. This line crosses the block from one end to the other. It is located at a distance :math:`\mathrm{0,4}` from the left edge and crosses the elements (see fig.2). The interface is said to be non-compliant.

The contact elements are introduced by the discretization CONTACT =' STANDARD 'in the operator MODI_MODELE_XFEM.

The cohesive law is then defined in the operator DEFI_CONTACT, by the keywords ALGO_CONT =' CZM 'and RELATION =' CZM_TAC_MIX'.

Surface elements are of type D_ PLAN.


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

The square is discretized at the rate of :math:`4` elements per side. Therefore:

Number of elements, type HEXA8: 16

Number of knots: 65.


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

The remark on control mentioned for modeling A also applies to this modeling. Strictly speaking, no longer having any interface elements in the model, we replace the tests on SIGN and SIGTX by tests on the contact multipliers X- FEM LAGS_C and LAGS_F1 respectively.

**Fashion** :math:`I`


.. csv-table::

    "**Size tested**", "**Reference**", "**Tolerance (** :math:`\text{\%}` **)**"
    "ETA_PILO ", "8.29181D-01", "0.10"
    "DXsur node 2", "2.16506D-08", "0.10"
    "SIXXsur mesh 32", "7.37899D-01", "0.10"
    "LAGS_Csur node 9", "3.47849D-01", "0.10"
    "LAGS_F1sur node 9", "0.D+00", "0.10"