Semi - Plenary Speaker: Li Cheng

Professor Li Cheng

Title: Acoustic Black Holes for Meta-material/structural Design
Affiliation: Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Hom, Kowloon, Hong Kong


Abstract
Flexural waves inside a structure under flexural vibration can be manipulated through the so-called Acoustics Black Holes (ABH) effects. Upon proper tailoring of the structural thickness, the phase velocity of the bending wave gradually reduces alongside thickness thinning, thus entailing high energy concentration and rich dynamics. The phenomenon arouses increasing interest from the scientific community and inspires innovative design solutions for light-weight and highly damped structures. Meanwhile, the reduced structural wave velocity allows for the creation of acoustically slow waves so that subsonic sound radiation regions can be formed inside a structure vibrating above the critical frequency, the consequent of which is the impaired sound radiation efficiency and reduced sound radiation. In this talk, ABH-enabled meta-material/structural design, in both 1D and 2D configuration, is discussed. Results show the realization of both directional or omni-directional bandgaps and the benefit for wave manipulation and sound radiation mitigation. 

 

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