LAUSR

The targeted energy transfer (TET) technique could be applied to reduce the low frequency noise by a nonlinear membrane absorber as nonlinear energy sink (NES) inside a tube or an acoustic cavity. The pre-stress of the nonlinear membrane can affect the desired working zone for the TET and also the suppressed amplitude of noise. In order to design the nonlinear membrane according to a given acoustic medium, the influence of the pre-stress of the nonlinear membrane is quantitatively studied in this paper. The analytical formulae over the pre-stress of the membrane are established based on a general model of the system with an acoustic mode of 3D acoustic cavity and one membrane. Meanwhile, the suppressed frequency bandwidth of noise is investigated under different pre-stress levels of the membrane by using harmonic balance method and numerical method. For convenient applications, the radial deformation analysis and the modal analysis of the membrane with the pre-stress are finally performed by finite element method (FEM) to obtain the relationship between the radial displacement and the first mode. It can be helpful to guide design of the pre-stress of the membrane NES according to the desired working zone for the practice engineering application in acoustic field.