.. _V6.03.159:

**v6.03.159** SSNP159 — Elastic energy in large plastic deformations of a bar under tension
=====================================================================================================

**Summary:**

This quasistatic mechanical test consists in subjecting a bar with a rectangular (:math:`\mathrm{3D}`) or cylindrical (:math:`\mathrm{2D}` axisymmetric) cross section to simple traction. The object is to validate the calculation of elastic energies in three deformation formalisms: 'PETIT', 'GDEF_LOG' and 'SIMO_MIEHE', with the command POST_ELEM.

In addition, the B modeling of this test case proposes to test the keyword factor ETAT_INIT proposed by the STAT_NON_LINE command, with GDEF_LOG. The user wishing to impose an initial state of constraint with the GDEF_LOG formalism will find the necessary information.

The bar is modelled by a volume element (HEXA20, ModelizationA) or quadrangular element (QUAD4, for axisymmetric modeling, modellingB).

The solution is analytical.


.. toctree::
    :hidden:

    self

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

    Probl_me_de_r_f_rence
    Solution_de_r_f_rence
    Mod_lisation_A
    Mod_lisation_B
    Synth_se_des_r_sultats