Research on active control of vibration sound radiation of typical stern hull structures

Electromagnetic harmonic excitation from shipboard motors readily induces low-frequency vibration and noise in the stern hull structure of ships, compromising its acoustic stealth performance. This study proposes an active control method utilizing piezoelectric stack actuators. The methodology encompasses: firstly, analyzing and validating the electromechanical coupling mechanism of the piezoelectric stack actuator. secondly, determining the inherent characteristics of the stern hull through in-air and underwater modal analyses. Furthermore, simulate the acoustic radiation behavior of the stern hull under the excitation of different sound sources. For typical motor rotational conditions, quantify the vibration spectrum of the stern hull and the power flow transmission characteristics from the motor base to the stern hull. Under the premise of ensuring that the fixture does not affect the dynamic characteristics of the original structure, simulate the open-loop vibration control effect of installing the piezoelectric stack actuator. Ultimately, constructing an experimental system to measure force ranges of exciters and piezoelectric stack actuators, and validating both open-loop and closed-loop vibration control schemes under representative conditions. Collectively, this integrated approach suppresses stern hull vibrations within critical low-frequency bands, establishing a robust framework for enhancing marine acoustic stealth.