.. _R3.08.06:

**r3.08.06** Finite elements of straight and curved pipes with ovalization, swelling and warping in elasto-plasticity
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**Summary:**

This document presents the modeling of a finite pipe element that can be used in elasticity or plasticity pipe calculations. Pipes, curved or straight, can be relatively thick (ratio of thickness to radius of the cross section up to :math:`0.2`) and are subject to various combined loads - internal pressure, plane and anti-plane flexures, torsion, extension - and can have a non-linear behavior.

This line element combines both shell and beam properties. The average fiber in the pipe behaves like a beam and the pipe surface behaves like a shell. The element produced is a pipe element that is straight or curved in small rotations and deformations, with elasto-plastic behavior under plane stresses.

Three models, corresponding to three different types of elements, are available:


* TUYAU_3M, which takes into account a maximum of 3 Fourier modes, and which can rely on 3-knot or 4-knot meshes.


* TUYAU_6M, which takes into account up to 6 Fourier modes, and is based on 3-knot meshes.



.. toctree::
    :hidden:

    self

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


    Introduction
    Les_diff_rentes_th_ories_de_coques_et_de_poutres_pour_les__l_ments_finis_de_tuyaux_droits_ou_coud_s
    El_ments_mixtes_coque-poutre_pour_les_tuyaux_droits_et_courbes
    Discr_tisation_num_rique_des_formulations_variationnelles
    Caract_ristiques_g_om_triques_de_l__l_ment_de_tuyau
    Raccord_tuyau-tuyau
    Raccords_coque-tuyau_et_3D-tuyau
    Implantation_de_l__l_ment_TUYAU_dans_Code_Aster
    Conclusion
    Bibliographie
    Description_des_versions_du_document