Science Daily May 30, 2023
Researchers in Japan numerically demonstrated an inverse design of a structure for camouflaging the location of a sound source as if the sound emanated from a different location. They used a topology optimization approach used in acoustic elastic coupled problems, the difference between the sound pressure fields emanating from an actual source and a virtual source, was the objective function infimized in camouflaging the sound source. Optimal topologies of elastic structures made of acrylonitrile butadiene styrene were designed for the camouflaging purpose, acoustic metamaterials were not used. The metastructures (source-shifters) were expressed at the design stage using a level-set method, which generated sharp interfaces between acrylonitrile butadiene styrene and air. The source-shifters were modeled in finite-element analyses as acoustic–elastic coupled systems and incorporated acoustic fluid–structure interaction. From studies of the underlying camouflaging mechanism and the dependence of camouflaging performance on the distance between actual and virtual locations, they evaluated the effectiveness of their scheme in camouflaging the location of sound sources… read more. TECHNICAL ARTICLEÂ
Graphical abstract. Credit: Journal of Sound and Vibration, Volume 559, 1 September 2023, 117768