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


Geometry
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We consider a square concrete tank with dimensions :math:`L\mathrm{\times }l\mathrm{\times }h\mathrm{=}10m\mathrm{\times }10m\mathrm{\times }5m` (medium to medium sheet) and :math:`0.4m` thickness.


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

Isotropic linear elastic material:

Young's module: :math:`E\mathrm{=}{3.10}^{4}\mathit{MPa}`,

Poisson's ratio: :math:`\nu \mathrm{=}0.15`,

Density: :math:`\mu \mathrm{=}2500\mathit{kg}\mathrm{/}{m}^{3}`.


Boundary conditions and loads
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The soil stiffness density applied under the tank is :math:`50\mathit{kN}\mathrm{/}{m}^{3}`.

The integral of this density based on the tank is therefore :math:`5{10}^{6}\mathit{kN}\mathrm{/}m`.

This quantity is then distributed over the nodes in the base.



The load consists of:


* the net weight of the tank


* the thrust of the water from the filled tank (constant pressure on the bottom and gradual pressure on the edges)


* an overload distributed around the outline at the top of the tank (:math:`20\mathit{kN}\mathrm{/}m`)


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