.. _R5.03.31:

**r5.03.31** Law of Behaviour FONDATION
==========================================

**Summary:**

This document describes the nonlinear elasto-plastic behavior of a rectangular surface foundation subjected to static or seismic three-dimensional stress. This law of behavior is affected on 3D discrete elements composed of a single translation/rotation node (DIS_TR) affected by a diagonal stiffness matrix (K_ TR_D_N) by means of the relationship FONDATION called by the nonlinear problem solving operators STAT_NON_LINE [:external:ref:`R5.03.01 <R5.03.01>`] or DYNA_NON_LINE [:external:ref:`R5.05.05 <R5.05.05>`]. The key word to define material characteristics in DEFI_MATERIAU is FONDA_SUPERFI.

The law represents both the sliding mechanism, the mechanism of loss of bearing capacity as well as the mechanism of detachment from the foundation. Before using one of the mechanisms mentioned above, all loading directions have linear elastic behavior described by classical stiffness characteristics.

In the law of behavior, there are three mechanisms that can be combined:


* the first representing the slip between the underside of the foundation and the ground (treated as a plastic mechanism with work hardening);


* the second representing the phenomenon of loss of load-bearing capacity under the effect of an excessive vertical load (treated, again, as a plastic mechanism with work hardening);


* The third representing the phenomenon of detach-gluing of the foundation under the effect of an important moment (treated as a non-linear elastic mechanism).

**Table of Contents**




.. toctree::
    :hidden:

    self

.. toctree::
    :maxdepth: 2
    :numbered:

    Pr_sentation_des_m_canismes_mis_en_jeu
    Implantation_dans_Code_Aster
    R_capitulatif_des_param_tres_de_la_loi_de_comportement
    R_capitulatif_des_variables_internes_de_la_loi_de_comportement
    R_f_rences_bibliographiques
    Description_des_versions_du_document