Experimental study on influence of wall acoustic materials of 3D cavity for targeted energy transfer of a nonlinear membrane absorber

Abstract

In view of applying the membrane nonlinear energy sink (NES) to reduce the low-frequency noise inside vehicle interior with acoustic absorption materials, a simplified acoustic cavity is used to model vehicle interior cavity. The system of one acoustic mode of the parallelepiped cavity and one membrane is established and the experimental set-up is built. The forced vibration responses in frequency-domain and time-domain are analyzed by using the set-up with and without the acoustic materials. Under certain excitation amplitude and frequency range, the strongly modulated responses (SMR) occurs and the plateau of suppressed resonance peaks appears. Meanwhile, the energy of the system is studied when the SMR exists. The targeted energy transfer (TET) phenomenon and the theoretical model of the system is verified by the experimental method. The wall acoustic materials of 3D cavity could affect the TET of the system, where the excitation amplitude for the beginning threshold of the desired working zone becomes larger and the excitation amplitude interval of TET becomes larger simultaneously. The ending threshold of the desired working zone of the NES is redefined. The numerical results are in good agreement with the experimental results. The application of membrane NES in 3D acoustic cavity proposed in this paper provides a new technical idea for vehicle interior low-frequency noise reduction in the future.