2. Benchmark solution

2.1. Calculation method

The infinitely rigid bearings and the absence of rotation of the shaft make it possible to perform a direct calculation with Code_Aster of the first natural modes of the massive-bearing-rotor structure which will serve as a reference for the substructured calculation in Code_Aster.

The validation of the consideration, by substructuring, of a generalized mass in a calculation of tree lines in Code_Aster will consist in comparing the natural frequencies obtained by a direct calculation and by a substructured calculation (substructuring of the Craig-Bampton type).

Efforts will also be made to validate each of the rotor-bearing and solid substructures separately.

In addition to the comparison between global calculation and substructured calculation in Code_Aster, we also validate the results with respect to those of CADYRO [1].

2.2. Reference quantities and results

Code_Aster results give both mode frequencies and modal deformations. Only the frequencies are actually tested.

2.3. References

1. CADYRO, finite element software intended to predict the dynamic behavior of rotors under bending validation file — note HP-61/94/049/B.