Parameters design of a nonlinear membrane absorber applied to 3D acoustic cavity based on targeted energy transfer (TET)

The targeted energy transfer (TET) phenomenon is demonstrated and analyzed between an acoustic medium inside a parallelepiped cavity and a thin viscoelastic membrane that is mounted on one wall of the cavity and that is working as a nonlinear absorber or a nonlinear energy sink (NES). Based on a two degrees-of-freedom (DOF) system, which is comprised by an acoustic mode of 3D acoustic cavity and a nonlinear membrane NES, the desired working zone for the membrane NES is defined and the two thresholds of the zone are obtained. In this paper, we investigate a parameter analysis of a nonlinear membrane absorber based on TET technique to design the NES. The physical parameters of the membrane and the place of the membrane on the wall of the cavity are studied. It can finally allow us to determine where is the better place for the membrane NES and which parameter affects mainly the desired working zone for the membrane NES that has to be used for reducing low frequency resonances inside a given acoustic cavity. Numerical simulations are preformed to validate the TET phenomenon and the results of the parameter analysis.