ANALYSIS AND DESIGN OF ACOUSTIC BLACK HOLE FOR BEAM PLATE STRUCTURES

Abstract

Acoustic Black Hole (ABH) has been developed for the flexural waves in beam and plate structures to efficiently focus the wave energy and reduce the vibration-acoustic level. Based on the existing investigations on the ABH, this thesis continues to study the behaviors of the ABH (1D and 2D ABH) for a better understanding on the ABH mechanisms from the viewpoint of wave propagation. Then, multiple approaches and design guidelines are proposed to improve the ABH performance in wave focusing and vibration absorption. These guidelines include the selection/optimization of the ABH profile parameters, placement of the ABH in periodic ABH structures, modification of the 2D ABH shape and other aspects. As a result, enhancements of the ABH performances have been demonstrated and analyzed. Furthermore, in terms of the wave and energy propagation, the equivalent wavenumber and structural intensity have been established and validated for the ABH design in the plate structures.