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


Geometry
---------

We consider a parallelepiped of dimensions :math:`4\mathrm{\times }4\mathrm{\times }2\mathit{mm}` with a plane crack:


.. image:: images/100002010000049D000002F92100DED386C126DA.png
    :width: 3.9366in
    :height: 2.5354in


.. _RefImage_100002010000049D000002F92100DED386C126DA.png:

Figure 1.1-1: crack geometry


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

We will propagate the crack in the figure by imposing the same propagation angle :math:`\beta` and the same advance :math:`\Delta a` at each point of the bottom in such a way that the bottom always remains straight:

:math:`\beta ={5}^{\text{o}}`

:math:`\Delta a\mathrm{=}0.6\mathit{mm}`


.. image:: images/10000201000006F3000005101438F2CA85C562A5.png
    :width: 2.8154in
    :height: 2.0508in


.. _RefImage_10000201000006F3000005101438F2CA85C562A5.png:

Figure 1.2-1: imposed propagation


.. _RefNumPara__36311907: