Investigation on vibration reduction performance of Quasi-3D spiral acoustic black hole for plate

Objectives The aim is to investigate the effect of Quasi-3D spiral acoustic black holes (Q-3D SABH) on the vibration suppression characteristics of flat plates, and to provide a new technical way for the vibration damping design of ship plate structures. Methods The study proposes the Q-3D SABH configuration with broadband vibration reduction for the first time, establishes a finite element computational model of a plate structure arranged with Q-3D SABH, calculates and analyzes the vibration response characteristics and velocity cloud diagram of the structure, and reveals the influence law and effect of Q-3D SABH on the vibration suppression of the flat plate through the form of energy flow as well as the modal loss factor. Results The results show that the vibration damping effect of Q-3D SABH on the flat plate is significantly better than that of the mass block and damping of the same mass. In the low-frequency band, the arrangement of Q-3D SABH reduces the mean-square vibration velocity level of the flat plate by more than 10 dB, and in the high-frequency band, the damping effect is as high as more than 15 dB, and the total vibration level is reduced by 15.05 dB in the whole frequency band; meanwhile, its damping performance is better than that of a one-dimensional spiral acoustic black hole of equal mass as a whole, and it is more obvious at middle and high frequencies..Conclusions It is shown that Q-3D SABH has excellent low-frequency broadband damping performance for plate structures with good convergent absorption of wave energy.