A novel identification tool for rotors working under non-stationary conditions based on the IAS

The aim of this work is to provide a new model describing the dynamic behavior of the rotating machinery working under non-stationary conditions with no assumption on the IAS. This new model will provide an identification tool for the rotor parameters. An example of a simple rotor made of a flexible shaft, a rigid disk, bearings and a mass unbalance is considered. The model shows a coupling between the torsional and flexural behavior and it is proven that, owing to this coupled behavior, the signal of the IAS contains information about, not only the rotation frequency of the response of the rotor, but also about its flexural behavior, when operating under non-stationary conditions.