Research on the performance of step toroidal acoustic black hole plates

The Step Toroidal Acoustic Black Hole (STABH) is a structural design aimed at enhancing energy concentration and vibration damping performance by geometrically modifying the conventional Acoustic Black Hole (ABH). This paper investigates the energy concentration behavior and vibration control capability of STABH plates. Based on acoustic black hole theory, finite element models of both the STABH and the conventional ABH are developed to comparatively analyze their vibration responses in the frequency and time domains. The effects of truncated thickness, radius, and power exponent on energy concentration are systematically examined via single-factor parametric analysis, and structural parameters are optimized using orthogonal experimental design. A viscoelastic damping layer is applied to the bottom surface of the optimized STABH structure to further enhance its vibration suppression performance. Results indicate that the STABH exhibits a more localized energy distribution in the mid-to-high-frequency range and faster time-domain decay with reduced residual vibration amplitude. The relative significance of the three parameters follows the order: radius > power exponent > truncated thickness. The optimal parameter combination yields an average vibration velocity level of 68.78 dB. With the integrated damping layer, the vibration velocity response across the entire frequency band is reduced by approximately 20 dB, markedly improving overall vibration suppression performance. This study provides both a theoretical foundation and practical engineering guidance for the design and application of high-performance acoustic black hole structures.