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




Calculation method
-----------------

Modal calculations were carried out over the range of rotation speeds from :math:`5000` to :math:`6000\mathrm{tr}/\mathrm{min}` with a step of :math:`250\mathrm{tr}/\mathrm{min}`. To validate the correct consideration of the linear variation of the characteristics of the bearings as a function of speed, a natural frequency calculation is also carried out at the speed of rotation :math:`5750\mathrm{tr}/\mathrm{min}`, which corresponds to the center of the speed range in question.




Reference quantities and results
-----------------------------------

The Code-Aster results give both the frequencies of the flexure, torsional, and traction/compression modes. The number of modes calculated is 12.




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


* M. LALANNE, G. FERRARIS, "Rotordynamics Prediction in Engineering", Second Edition, Wiley, 2001.


* ROTORINSA, finite element software intended to predict the dynamic behavior of rotors under bending, La MCoS UMR5259, INSA -Lyon.