B modeling
==============


But
---

In this modeling, we want to validate the use of spring mats with zero length DIS_T elements. The feature is already validated for zero-length DIS_TR elements. So that provides the reference values.


Description
-----------

A structure in the form of a parallelepiped composed of a single element rests on a carpet consisting here of 4 springs. A constant force is imposed on a vertex node of cube :math:`\mathit{XY}0` (with components in the 3 directions of space). We then check that the displacement values at node :math:`\mathit{XY}0` are the same with modeling DIS_T as with modeling DIS_TR (reference).


.. image:: images/10000201000001D50000011F9622E5E7A4F95123.png
    :width: 3.2429in
    :height: 1.761in


.. _RefImage_10000201000001D50000011F9622E5E7A4F95123.png:


Geometry
~~~~~~~~


Material parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~

**Structure**:

Young's module: :math:`30000\mathit{MPa}`

Poisson's ratio: :math:`0.3`

Density: :math:`2500\mathit{kg}/{m}^{3}`

**Springs:**


.. csv-table::

    "**GROUP_NO**", "**Stiffers**", "**Dampening**"
    "DIS_TR ", "1E6,1E6,1E6,2.5E6,2.5E5,2.5E5,5.E5", "1E3, 1E3, 1E3, 1E3, 2.5E2, 2.5E2, 5.E2"
    "DIS_T ", "1E6,1E6,1E6", "1E3,1E3,1E3"


**Note:** The rotation values on the DIS_TR given to RIGI_PARASOL in this specific case allow the rotation values to be zero on each element of the spring belt.


Loads
~~~~~~~~~~~

The following constant forces are imposed on node :math:`\mathit{XY}0`:


* :math:`\mathit{FX}=1000N`


* :math:`\mathit{FY}=2000N`


* :math:`\mathit{FZ}=-3000N`


Tested values
---------------

We test the values at the final moment: :math:`0.5s`


.. csv-table::

    "**GROUP_NO**", "**NUME_ORDRE**", "**Component**", "**Reference**", "**Reference Value**"
    "XY0 ", "4331"," :math:`\mathit{DX}` "," "," AUTRE_ASTER ", "-0.00210267324236"
    "XY0 ", "4331"," :math:`\mathit{DY}` "," "," AUTRE_ASTER ", "0.00175325119557"
    "XY0 ", "4331"," :math:`\mathit{DZ}` "," "," AUTRE_ASTER ", "-0.00691531181833"