Research on broadband vibration control mechanism of an acoustic black hole beam with an adjustable stiffness internal boundary

The acoustic black hole (ABH), as a vibration control technology, provides a way for vibration and noise control by realizing the aggregation and dissipation of vibration energy through the design of special geometric structures. Due to processing limitations, truncated thickness reduces wave capture efficiency. Additionally, as damping layers poorly dissipate low-frequency energy, most ABH research focuses on high frequencies. This study explores coupling an ABH beam with an adjustable boundary to extend the ABH effect's effective frequency range and improve vibration control. By integrating adjustable stiffness theory, the design enhances low-frequency energy trapping and enables broadband vibration suppression. Results demonstrate broader frequency coverage, extending ABH effectiveness to lower frequencies while ensuring structural feasibility. The method offers flexible, adaptive control with simple implementation, highlighting its potential for advanced vibration control applications.