.. _U2.01.09:

**u2.01.09** Definition of a constraint field and an initial internal variables field
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**Summary:**

We explain how to manufacture two of the fields constituting the initial state of a non-linear calculation (STAT_NON_LINE): the constraint field and the internal variables field.


* the components of the stress field have an "analytical" form (for example: state of a soil subject to the "weight of land"),


* the components of the internal variables field are non-zero constants.

In both cases, the solution is to chain together a certain number of CREA_CHAMP commands.

For the constraint field, the difficulty lies in evaluating the "analytical formulas" (OPERATION =' EVAL ').

For the field of internal variables, the difficulty arises from the fact that the quantity associated with the internal variables (VARI_R) has an a priorily undetermined number of components: 'V1', 'V2',...

The proposed solutions are implemented in test ZZZZ130A.


.. toctree::
    :hidden:

    self

.. toctree::
    :maxdepth: 2
    :numbered:

    D_finition_du_champ_de_contraintes_analytique
    D_finition_du_champ_de_variables_internes_non_nul