Design of One-Dimensional Acoustic Meta-Filter with Multiple Resonators
New design structure for generating and tuning the multi-bands of negative modulus is presented by introducing metamaterial concept. To effectively achieve selective noise reduction and sound transmission, acoustic metamaterial consisted of arrayed multiple resonators with extended necks is proposed. Also, theoretical expression for the effective bulk modulus is developed by using a mechanical-acoustic analogy. The bandwidths and center frequencies of multi-bands are tuned by changing only the mass ratio of the extended necks, which are converted to equivalent mass elements. Numerical investigation by using FEM simulation (COMSOL Multiphysics®) is carried out to support the theoretical expression and tunability performance of multi-bands in the acoustic metamaterial. In view of the date of many passive acoustic filters and ultrasonic devices, it is expected that the proposed design structure can overcome the limitations of sound blocking in a low frequency range and precise signal transmission.
