5. Summary of results

A good correspondence is obtained between the results simulated with CADYRO and Code_Aster (relative errors less than 3%). However, significant differences (of 20% at most) are obtained with the results from the bibliography. These differences can simply be explained by the difference in the projection base. In fact, the spatial base used in the bibliography only takes into account the first natural mode of a flexure beam on simple supports. Code_Aster and CADYRO use a more accurate modal base. The method of resolving by modal recombination on an incomplete basis is very sensitive to truncation effects that tend to rigidify the structure overall. This therefore has the consequence of increasing the resonance frequencies, which explains why the peaks appear for higher rotation speeds and therefore later in time (increase in speed here). A good implantation of the gyroscopic damping and stiffness matrices for the girder element is therefore observed, in the case of calculating the temporal response on a modal basis for a transient increase in speed.