Investigation on the vibration reduction performance of spiral acoustic black hole for ring-stiffened cylindrical shell

Abstract：Objectives The aim is to investigate the vibration reduction characteristics of Spiral Acoustic Black Hole (SABH) on ring-stiffened cylindrical shell and to provide a new technical approach for the vibration reduction design of ring-stiffened cylindrical shell. Methods The investigation establishes a finite element computational model of the ring-stiffened cylindrical shell with SABH arrangement, calculates and analyzes its structural natural frequency and vibration response characteristics. The influence of SABH arrangement position, helix length and numbers on the vibration suppression of the ring-stiffened cylindrical shell is also investigated Results The results show, a single SABH is arranged on the web, and the resonance peak of each mean square vibration level of the web is significantly reduced, and the first resonance peak is reduced up to 6 dB or more, the other resonance peaks are reduced by 13 dB or more, arranged on the shell, the peak value of each mean square vibration level of the shell is reduced by 8 dB or more. Increasing the helix length and the number of SABH can further improve the vibration reduction effect of SABH. Conclusions SABH has minimal effect on the intrinsic frequency of ring-stiffened cylindrical shell and has excellent low-frequency broadband vibration reduction performance. This investigation is of great significance in guiding the application of SABH in vibration reduction of ring-stiffened cylindrical shell.