Research on a piezoelectric actuator-driven vibration isolation support for vibration control of a shaft-hull system

Abstract A piezoelectric actuator-driven vibration isolation support (PAVIS) is proposed to suppress lateral vibration transmission from the propulsion shaft to the hull structure of an underwater vehicle subjected to the excitation of dynamic propulsion forces. The PAVIS is composed of hexagonal frames and embedded piezoelectric actuators and is arranged orthogonally between the bearing housing of the propulsion shaft and the hull structure as an alternative to the conventional support fabricated by plates. To investigate the feasibility of the PAVIS in vibration isolation, the dynamic model of a shaft-hull system is established on the Timoshenko beam theory and the frequency response function (FRF)-based synthesis method. The characteristics of power flow through the PAVIS are analyzed with this model. Furthermore, the feasibility of the PAVIS in vibration transmission control is analyzed on the assumption that the error responses are completely suppressed, and the results show that the mean square velocity as well as the acoustic power of the hull structure can be attenuated. The effectiveness of the PAVIS was also validated by an experimental test rig, and the experimental results imply that the PAVIS can be applied to reduce vibration transmission between two parts as an active intermediate structure.