.. _U2.06.31:

**u2.06.31** Gyroscopy modeling instructions
====================================================

**Summary:**

Linear and non-linear modal or dynamic analyses of tree lines require the integration of the concept of gyroscopic damping. The analysis of a rotational speed transient (increase in speed or deceleration) requires, for its part, to integrate the concept of gyroscopic stiffness.

Dedicated rotating machine codes use a preferred axis for rotor modeling (:math:`Y` for ROTORINSA, :math:`Z` for CADYRO, etc.). In *Code_Aster*, it is possible, with some precautions in the data layout, to model a rotor with any axis of rotation. Once the axis of rotation is chosen, the positive direction along this axis is defined as being the usual **trigonometric** direction of rotation.

This user manual is an aid to the use of the gyroscopic damping and stiffness functionalities. It must allow it to carry out a coherent and correct calculation of rotating machines, regardless of the axis of rotation of the shaft line.




.. toctree::
    :hidden:

    self

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

    Amortissement_et_raideur_gyroscopiques
    Exemple_de_calcul_ligne_d_arbres_avec_axe_selon_X
    Exemple_de_calcul_de_ligne_d_arbres_avec_axe_quelconque
    R_f_rences_bibliographiques