Analysis of the vibration responses of an onboard rotor system

A mathematical reliable model to represent the dynamic behavior of onboard rotors is obtained considering various subsystems. In this sense, the most important subsystems are the following: first, the subsystems that can be defined by their geometry, such as the shaft, discs and couplings; then, the subsystems that are dependent on the frequency and/or lateral displacements and velocities of the shaft, the bearings, the gyroscopic effect, and clearly the efforts applied to the system through its base. In this context, this paper aims at analyzing the dynamic behavior of a flexible rotating machine considering base excitations. The rotating machine used in this work is composed by a horizontal flexible shaft containing two rigid discs and supported by two ball bearings. In this case, the base of the rotor system is considered rigid. Therefore, the proposed analysis is performed both in the time and frequency domains, as represented by the orbits, unbalance responses, and the FRFs of the rotor system.