.. _V5.02.138:

**v5.02.138** SDNL138 - Frequencies and natural modes of vibration of a self-stressed frame
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**Summary:**

The objective of this test is to validate the calculation of the vibration frequencies and modes of vibration of a self-stressed frame. The forces in the structure are only generated by the tension of the cables. The principle of the test case is to:


* perform a non-linear calculation,


* retrieve the various fields at a given moment,


* calculate stiffness and mass matrices,


* calculate vibration frequencies and modes.

Several models are carried out:


* calculation with STAT_NON_LINE, use of operators CALC_MATR_ELEM, ASSE_MATRICE and COMB_MATR_ASSE for assembling matrices. Then calculate the frequencies and vibration modes with operator CALC_MODES.


* calculation with DYNA_NON_LINE and option MODE_VIBR.


* calculation with STAT_NON_LINE, determination of the stiffness matrix using the CALCUL operator. Then calculate the frequencies and vibration modes with operator CALC_MODES.

The results are compared to a theoretical solution.


.. toctree::
    :hidden:

    self

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

    Probl_me_de_r_f_rence
    Solution_de_r_f_rence
    Mod_lisation_A
    Mod_lisation_B
    Mod_lisation_C
    Synth_se_des_r_sultats