Theoretical analysis on hybrid local piezoelectric and conductive effect on sound absorption performance of porous poly(vinylidene fluoride)

Sound absorption performance of porous poly(vinylidene fluoride) (PVDF) foams was investigated using a finite element model. Analyses with acoustic modelling and numerical simulation on a hollow PVDF cylinder showed the combination of piezoelectric and conductive effects substantially contributed to airborne sound absorption. The piezoelectric effect did not take any effect on the sound absorption when the piezoelectric cylinder was an ideal dielectric without any conductivity to dissipate the charges generated from the piezoelectric effect. The maximum noise mitigation effect occurred when the resistive and capacitive impedances match. The agreement between the simulation results and previous experimental observations indicated that the high performance airborne sound absorption in semi-conductive foams was achieved due to hybrid local piezoelectric effect for converting sound to electricity and appropriate internal conductive function to dissipate the electrical charges.