Experimental study of targeted energy transfer inside 3d acoustic cavity coupled by a nonlinear membrane absorber

摘要

In order to study the feasibility of using the targeted energy transfer(TET) phenomenon of nonlinear energy sink(NES) to reduce the vehicle interior noise in low- frequency domain, based on the previous theoretical research, this paper will go further to explore the coupling characteristics between 3d acoustic cavity and nonlinear membrane absorber from the perspective of experiment. According to the vehicle interior space, an experimental set-up of simplified regular steel-made 3d acoustic cavity is constructed and coupled to a nonlinear membrane absorber served as a NES. Based on this set-up, the system's forced and free vibration responses under sinusoidal excitation are measured, respectively. The experimental results show that, under a certain frequency and amplitude of the external excitation, the strong modulated response(SMR) regime, in which the noise energy inside 3d acoustic cavity will rapidly be accumulated in the nonlinear membrane absorber and then dissipated based on its damping, appears in the responses. This is consistent with the results of the theoretical model. The research on the application of NES to 3d acoustic cavity proposed in this paper provides a new technical idea for vehicle interior low-frequency noise reduction in the future.