Acoustic Characterization of Additive Manufactured Micro-Perforated Panel Backed by Honeycomb Structure

This paper examines the acoustic properties of additive manufactured micro-perforated panel backed by a periodic honeycomb structure. The acoustic absorption coefficient of the periodic honeycomb structure is improved by providing a thin layer of the micro-perforated panel in front of the honeycomb structure. The complete structure is printed by Acrylonitrile Butadiene Styrene (ABS) polymer material by extrusion-based Fused Filament Fabrication (FFF) technique of Additive Manufacturing (AM). To investigate the effect of perforation ratio, samples with different infill percentages (IP) are fabricated and their normal sound absorption coefficients are measured in an impedance tube. The predicted results agree well with measured results in the considered frequency range. Results show that the frequency of maximum absorption can be tuned by varying perforation ratio from mid to low frequency range.