A monostable acoustic metamaterial for broadband low frequency sound absorption ∗

This paper presents a monostable acoustic metamaterial for achieving a broadband sound absorption in low frequencies. The proposed system is realized by placing a flexible panel with a magnetic proof mass in a symmetric magnetic field. An equivalent circuit model of such a system is presented. It is shown that the sound absorption peak significantly shifts downwards with the increasing magnetic field. In the nonlinear regime, the jump phenomenon is observed in the frequency sweeping test. Numerical simulation demonstrates that the proposed design can realize a broadband low frequency sound absorption in the deep subwavelength scale.