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


Geometry
---------

The geometry of the problem is that of a cube with side 200
whose faces are called :math:`\mathit{Face1}`, :math:`\mathit{Face2}`,
:math:`\mathit{Face3}`, :math:`\mathit{Face4}`, :math:`\mathit{Face5}`, and :math:`\mathit{Face6}`.


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

It is an isotropic linear elastic material with Young's modulus :math:`1.` and Poisson's ratio :math:`0.3`.


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

The cube is embedded on its side :math:`\mathit{Face1}` while all the others are subject to fluid pressure.

Fluid pressure is defined here as a pressure field on the fluid mesh depending on time and space depending on the function
:math:`10^{-4} \times \mathrm{INST} \times (X_f+Y_f+Z_f)`, where :math:`(X_f,Y_f,Z_f)` are the coordinates on the deformed configuration.
For this purpose, the fluid pressure is considered to be the same.

Characteristics of modeling
-----------------------------------

The solid calculation is carried out at the times :math:`0.2`, :math:`0.4`,,, :math:`0.6`, :math:`0.8` and :math:`1`.

For cases of weak coupling, a relative residue on the displacement increment of :math:`10^{-6}`
is required to move on to the next time step.


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

The initial conditions are free of any displacement and constraints.