Inhomogeneous acoustic black hole lattice design for superior vibration suppression

Achieving superior vibration suppression in lightweight engineering structures has been a long-standing challenge of considerable interest. In response, this work integrates the acoustic black hole (ABH) concept into lattice structures, constructing the acoustic black hole lattice structures (ABH-Lattice). In this work, a novel design for ABH-Lattice is proposed, replacing conventional thickness tapering with gradient parameterization of effective mechanical properties at lattice units scale. The design methodology is established using the inhomogeneous Euler-Bernoulli beam model combined with the dynamical homogenization technique. Numerical and experimental investigations confirm the vibration suppression performance of ABH-Lattice, in both frequency and time domains. A perturbation-based analysis was employed to reveal the underlying energy convergence phenomenon behind the exceptional vibration damping capabilities of the ABH-Lattice. Furthermore, the effective parameter governing the energy convergence effect is derived and used to study the influence of structural parameters on vibration suppression. Finally, the integration of local resonators with the ABH-Lattice was investigated, revealing a remarkable synergistic effect. This coupling significantly expanded the local resonance bandgap. This innovative ABH design for lattice structures meets engineering demands for vibration reduction, providing a simple yet effective solution for vibration control in practical applications and holding significant potential for engineering implements.