Acoustics Black Holes(ABH)effects can be achieved through manipulations of bending wave propagation inside a thin-walled structure with its thickness tailored according to a power-law variation.In doing so,the phase v...Acoustics Black Holes(ABH)effects can be achieved through manipulations of bending wave propagation inside a thin-walled structure with its thickness tailored according to a power-law variation.In doing so,the phase velocity of the bending wave gradually reduces alongside thickness thinning,eventually to zero in the ideal scenario at the wedge tip/indentation center,resulting in zero wave reflection and high energy concentration within a small localized area.The phenomenon attracts increasing attentions as a promising passive vibration control method because vibration energy can be channeled and only a very small amount of damping material is required within the energy focalization region to achieve efficient damping to flexural waves.In addition,the wave slowing phenomenon allows the creation of a subsonic region inside a supersonic structure,thus reducing the its overall sound radiation efficiency.These unique features point at a great potential of the ABH technology for various applications such as vibration control,sound radiation reductions and energy harvesting.This talk summarizes some of the recent progress made in the study of the ABH.Topics cover the semi-analytical modelling of the ABH structures;design and analysis of a double-layer compound ABH beam for improved static and dynamic properties;combination of locally resonant and Bragg scattering for broadband stopband creation as well as some examples of ABH for vibration and sound noise control applications.展开更多
文摘Acoustics Black Holes(ABH)effects can be achieved through manipulations of bending wave propagation inside a thin-walled structure with its thickness tailored according to a power-law variation.In doing so,the phase velocity of the bending wave gradually reduces alongside thickness thinning,eventually to zero in the ideal scenario at the wedge tip/indentation center,resulting in zero wave reflection and high energy concentration within a small localized area.The phenomenon attracts increasing attentions as a promising passive vibration control method because vibration energy can be channeled and only a very small amount of damping material is required within the energy focalization region to achieve efficient damping to flexural waves.In addition,the wave slowing phenomenon allows the creation of a subsonic region inside a supersonic structure,thus reducing the its overall sound radiation efficiency.These unique features point at a great potential of the ABH technology for various applications such as vibration control,sound radiation reductions and energy harvesting.This talk summarizes some of the recent progress made in the study of the ABH.Topics cover the semi-analytical modelling of the ABH structures;design and analysis of a double-layer compound ABH beam for improved static and dynamic properties;combination of locally resonant and Bragg scattering for broadband stopband creation as well as some examples of ABH for vibration and sound noise control applications.
