Objective This study aims to investigate how Quasi-3D Spiral Acoustic Black Holes (Q-3D SABHs) reduce vibrations in flat plate structures. It seeks to provide a new technical approach for designing ship plate structures with improved vibration damping. With the increasingly stringent requirements for noise and vibration control in marine engineering, this study addresses the need for efficient and broadband vibration reduction methods.

Method To achieve this objective, a new configuration of the Q-3D SABH is proposed to achieve effective broadband vibration reduction. A detailed finite element computational model of a flat plate with attached Q-3D SABH structures is developed. The vibration response characteristics of the plate are systematically analyzed through numerical simulations. Furthermore, the structural intensity distribution and modal loss factors are calculated to investigate the underlying damping mechanisms and the effectiveness of energy convergence and dissipation induced by the Q-3D SABH. Comparative analyses are also conducted to evaluate the performance of the Q-3D SABH against conventional vibration damping methods, such as mass blocks, traditional damping materials, and one-dimensional Spiral Acoustic Black Holes (1D SABH) with equal mass.

Results The results demonstrate that the Q-3D SABH exhibits significantly better vibration damping performance than conventional treatments, such as adding mass blocks or using traditional damping layers, and also outperforms one-dimensional Spiral Acoustic Black Holes (1D SABH) of the same mass. Specifically, in the low-frequency band, the Q-3D SABH configuration effectively reduces the mean-square vibration velocity level of the flat plate by more than 10 dB. In the mid- and high-frequency bands, the vibration damping performance is even more significant, achieving reductions of over 15 dB. Across the entire frequency range analyzed, the total vibration level is reduced by 15.05 dB. Moreover, compared to 1D SABH structures of equivalent mass, the Q-3D SABH demonstrates superior damping performance, particularly in the mid- and high-frequency ranges.

Conclusion The study concludes that the Quasi-3D Spiral Acoustic Black Hole structure has an excellent ability to converge and dissipate bending wave energy. The Q-3D SABH structure achieves outstanding broadband vibration reduction, especially at low frequencies, which are often challenging for traditional damping methods. These findings provide theoretical and technical support for the innovative design of vibration and noise control solutions in ship plate structures and other engineering applications where lightweight and efficient damping is critical. This research highlights the promising application potential of Q-3D SABH in advancing vibration damping technologies for large flexible structures.