Vibration Suppression Performance of Acoustic Metamaterial Beams with Different Layers of Mass Spring Resonators

Flexural and longitudinal elastic wave propagation is investigated for an acoustic metamaterial beam. First, the definition of stopband and finite element modeling are presented for the beam. The effects of adding one, two, and three layers of locally resonant subsystems to the met-amaterial beam are investigated. Each of the subsystems can act as a Tuned Mass Damper sys-tem and create one frequency stopband; therefore, the metamaterial beam is working on the principle of conventional locally resonant vibration systems. If the wave frequency is inside the stopbands, it will excite the resonator masses in the optical mode and cause a counter-active shear force, which helps the beam to remain straight. Modeling is based on the FEM method and is done in MATLAB software. It will be observed that each of the layers of mass-spring provides a stopband frequency over which the locally resonant system oscillates instead of the main beam. The location of frequency stopbands can be tuned with mechanical parameters of the mass-spring subsystems

Keywords:

acoustic metamaterial beam , locally resonant system , stopband , vibration absorb-ers.