Mechanics problems in application of acoustic black hole structures

Acoustic black hole (ABH) efiect utilizes the gradient variance of the structural conflguration or material properties to diminish wave velocity in the structure. The wave velocity decreases to zero in an ideal scenario, resulting in zero reflection. The mainstream method to realize ABH efiect is to tailor the structure thickness properly, such that energy is captured in a certain area. Great advantages and potential in applications for flexural wave manipulation in thin-walled structure result from its high e-ciency, broadband characteristics and flexible implementation. We introduce basic principles of ABH efiect, recent progress of related mechanical problems, and problems to be further explored. We describe the modeling and analysis method of ABH structure, the method and progress of experimental studies, manipulation and propagation of waves in ABH structures, and related issues in engineering applications of ABH structures.