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


Geometry
---------

It is a material point, processed by SIMU_POINT_MAT in 3D or in D_ PLANselon modeling.


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

The material obeys the law of elastic behavior, on which viscous regularization is superimposed. The parameters of behavioral validity:


.. csv-table::

    ":math:`E=200000\text{MPa}` ", "Young's module"
    ":math:`\mathrm{\nu }=0.3` ", "Poisson's ratio"
    ":math:`k=100000\text{MPa}` ", "Stiffness of viscous regularization"
    ":math:`\mathrm{\tau }=10\text{s}` ", "Characteristic time of viscous regularization"



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

It is a request at a material point (SIMU_POINT_MAT). All deformation components are imposed; they are all zero except EPXX. A deformation rate of :math:`{\dot{\epsilon }}_{\mathit{xx}}={10}^{-3}{\text{s}}^{-1}` is prescribed for 20 s, until a deformation of 2% is reached.


Initial conditions
--------------------

This is the natural state, all fields are zero.