.. _R4.04.05:

**r4.04.05** Elasto-viscous behavior model META_LEMA_ANI with metallurgy taken into account for fuel rod sheath tubes
======================================================================================================================================================

**Summary:**

In order to carry out 3D calculations of the fuel sheath in an accidental situation of type APRP, the MMC department has formulated, for Zircaloy tubes, a model of elastoviscous behavior, without threshold, anisotropic and taking into account the effect of the transformation of the alpha beta phase on mechanical behavior.

This model, available in *Code_Aster* under the name META_LEMA_ANI, and its resolution algorithm are described here. It is available in 3D, plane deformation, axisymmetry.

The Hill anisotropy matrix can be filled in either in Cartesian coordinates, or in the cylindrical coordinate system associated with the tube. To date, it has been assumed that the axial axis :math:`z` of the cylindrical coordinate system associated with the tube corresponds to that of the global coordinate system. So if several tubes have to be modelled or if the axis of the tube does not correspond to that of the global coordinate system, the model is not correct. Ultimately, this restriction should be lifted.

The speed equations are integrated numerically by an implicit Euler diagram. The system of equations obtained is solved by Newton's method.

**Table of Contents**




.. toctree::
    :hidden:

    self

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

    Contexte
    Relation_META_LEMA_ANI_dans_Code_Aster
    Notations
    Pr_sentation_du_mod_le_META_LEMA_ANI
    Int_gration_du_mod_le
    Bibliographie