AXIAL VIBRATION CONTROL OF PROPELLER SHAFT SYSTEM USING DYNAMIC ANTI-RESONANCE VIBRATION ISOLATOR

摘要

Harmonic axial force resulting from a propeller's first vibration mode is a major cause of tonal sound radiation of an underwater vehicle. To reduce the harmonic force, we employ a dynamic anti-resonant vibration isolator (DAVI) in parallel with thrust bearing of the shafting system to attenuate vibration transmitted to the hull. Method of transfer matrices and substructure synthesis are used to create a semi-analytical dynamic model of the propeller-shaft-hull system with DAVI. In this model, the elastic properties of the propeller and foundation are taken into consideration. The force transmissibility is then used to evaluate the isolation performance of DAVI. Finally, parametric studies are conducted to reveal the effects of the parameters of DAVI on the vibration control performance. It is demonstrated numerically that by using the DAVI, the vibration transmission to the hull is greatly attenuated at the designed frequency without obviously changing the axial fundamental resonance frequency of the shafting system.