Modeling A
==============


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

This is an axisymmetric :math:`\mathrm{2D}` modeling, where we can identify 2 groups of elements:

Axisymmetric modeling (keyword AXIS) for concrete and steel elements.

Axisymmetric crack modeling (keyword AXIS_JOINT) for the joint element.

Concrete and steel are modelled with QUAD4 elements.

The interface is modelled with degenerate QUAD4 elements (nodes combined).


.. image:: images/1000000000000344000002B489329187BC772315.png
    :width: 5.4957in
    :height: 4.4854in


.. _RefImage_1000000000000344000002B489329187BC772315.png:

**Figure 4.1-a: Axisymmetric test modelling**


Characteristics of the mesh
----------------------------

Number of knots: 94 (with 20 knots combined)

Number of meshes and type: 11 QUAD4 for steel

+ 9 QUAD4 for the interface

+ 54 QUAD4 for concrete.


Tested sizes and results
------------------------------

We test the components :math:`\mathit{xy}` of the element that correspond to the tangential components of the local law of behavior in the interface, using the constraint field SIEF_ELGA. The values are tested at the Gauss 2 point of the joint element, at 4 different time steps: at the beginning of loading, during the growth phase of the damage, in the peak of maximum strength and after the peak of bond strength.

**Field** **SIEF_ELGA component** **SITX**


.. csv-table::

    "**Identification**", "**Reference**", ":math:`\text{\%}` **tolerance**"
    "For an imposed displacement
    :math:`{U}_{\mathit{TT}}\mathrm{=}0.2\mathit{mm}` ", "-7.20 E+00", "5"
    "For an imposed displacement
    :math:`{U}_{\mathit{TT}}\mathrm{=}0.8\mathit{mm}` ", "-1.14 E+01", "5"
    "For an imposed displacement
    :math:`{U}_{\mathit{TT}}\mathrm{=}1.0\mathit{mm}` ", "-1.26 E+01", "5"
    "For an imposed displacement
    :math:`{U}_{\mathit{TT}}\mathrm{=}1.6\mathit{mm}` ", "-1.22 E+01", "5"



Evolution of damage
----------------------------

To observe the coherence of the evolution of the damage in the various connecting elements, the graph of the damage variable in relation to the imposed displacement is constructed.


.. image:: images/Object_22.svg
    :width: 590
    :height: 417


.. _RefImage_Object_22.svg: