Reference problem
=====================


Geometry
---------


.. image:: images/10000201000002D00000021CDDB93721ADEF81D3.png
    :width: 4.6992in
    :height: 3.5244in


.. _RefImage_10000201000002D00000021CDDB93721ADEF81D3.png:

The geometry is a fuel rod with a height :math:`\mathrm{4,5}m`, a thickness :math:`\mathrm{0,5}\mathrm{mm}` and a diameter :math:`\mathrm{0,9}\mathrm{cm}`, regularly attached, via the support grids, to a guide tube, more rigid, of thickness :math:`\mathrm{0,5}\mathrm{mm}` and of diameter :math:`\mathrm{1,245}\mathrm{cm}`.


Material properties
----------------------

The material is homogeneous, isotropic, and linear elastic. The elastic coefficients are:


1. :math:`E=98400\mathrm{MPa}`, :math:`\nu =0.3`, and :math:`\rho =6526{\mathrm{kg.m}}^{-3}` for the guide,


2. :math:`E=98400\mathrm{MPa}`, :math:`\nu =0.3`, and :math:`\rho =6526{\mathrm{kg.m}}^{-3}` for the pencil.


Mechanical modeling
----------------------

The grids are DIS_TR stiffness elements, the pencils are POU_D_T Timoshenko elements.


Boundary conditions and loads
-------------------------------------

The pencil is embedded at its ends, and only movements according to :math:`\mathrm{DX}` are allowed.