Dynamic sound absorption characteristics of a series piezoelectric acoustic absorber regulated by voltage

A piezoelectric acoustic absorber composed of double micro-perforated panels (MPPs) and their back cavity is studied in this paper. The outer layer of the MPP absorber is a common metal MPP, and the inner layer is a piezoelectric MPP made of polyvinylidene fluoride (PVDF) film. When an alternating voltage is applied to the polyvinylidene fluoride (PVDF)-micro-perforated panel (MPP), it can be excited to generate different structural vibration modes, which can bring an additional absorption peak to the absorption performance curve of the piezoelectric acoustic absorber. The numerical simulation and experimental results indicate that the frequency and sound absorption coefficient of the additional sound absorption peak are closely related to the voltage parameters. Especially when the frequency of the alternating voltage is close to the eigen-frequency of PVDF-MPP, the additional sound absorption peak is more significant. Therefore, the absorption coefficient of the piezoelectric acoustic absorber at the corresponding frequency can be effectively enhanced by appropriately adjusting the parameters of the excitation voltage. This method of selectively and specifically improving the sound absorption performance of the required frequency band is very effective in reducing the noise in the dynamic change.