Benchmark solution
=====================

This solution [:ref:`bib4 <bib4>`] is the one obtained with the SAMCEF [:ref:`bib1 <bib1>`] software. The modeling is based on a shell theory in resultant efforts with a co-rotational formulation [:ref:`bib3 <bib3>`] and a discretization DSQ [:ref:`bib2 <bib2>`].


.. image:: images/Object_11.svg
    :width: 316
    :height: 208


.. _RefImage_Object_11.svg:

The mesh considered is

.. image:: images/Object_12.svg
    :width: 316
    :height: 208


.. _RefImage_Object_12.svg:

quadrilateral elements.

Newton's strategy with imposed force level illustrates a difficulty of convergence. We push the calculation up to

.. image:: images/Object_13.svg
    :width: 316
    :height: 208


.. _RefImage_Object_13.svg:

.


Bibliographical references
---------------------------


1. SAMCEF, V7.1 Volume Elements Reference Manual,1998


2. J-L. Batoz, G.Dhatt, "Modeling Structures by Finite Elements: Shells", Hermès, Paris, 1992


3. Crisfield M.A., "Non-linear Finite Element Analysis of Solids and Structures", Volume 1: Essentials, John Wiley, Chichester, 1994


4. Ph. JETTEUR, Nonlinear Shell Kinematics. Report SAMTECH, Contract PP/GC-134/96, 1998