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


Geometry
---------


.. image:: images/1000050A00000E0E00000BFD3AE61FF5E250652D.svg
    :width: 181
    :height: 154


.. _RefImage_1000050A00000E0E00000BFD3AE61FF5E250652D.svg:

It is a thin sphere, with an average radius :math:`{R}_{m}=2.5m`, and a thickness of :math:`t=0.1m`.


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

The material is homogeneous, isotropic, and linear elastic. The elastic coefficients are: :math:`E=\mathrm{200 000 }\mathrm{MPa}` and :math:`\nu =0.3`.

The density is constant and is equal to: :math:`\rho =7800\mathrm{kg}/{m}^{3}`.


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

The structure is free in space.