Impact of structural parameters on the acoustic performance of 3D-printed perforated panels combined with polyurethane foam

The efficient mitigation of acoustic disturbances is essential for various applications. The primary purpose of this work is to investigate how structural parameters of a hybrid acoustic structure, integrating 3D-printed perforated panels and open-pore polyurethane foam, influence its sound absorption properties. Various configurations of this acoustic structure were examined, maintaining a consistent total thickness of 25 mm but varying individual layer thicknesses. Panel thicknesses ranged from 0.5 mm to 2.0 mm, with corresponding foam layers adjusted to maintain the overall thickness. Perforation diameters ranged from 0.5 mm to 2.0 mm, and the number of holes varied systematically between 50 and 250. The focus was on lower frequencies up to 2000 Hz. The 1/3rd octave frequency bands were used to quantify the Sound Absorption Coefficient, with the Noise Reduction Coefficient used for a holistic understanding of acoustic properties. The acoustic performance exhibited frequency-dependent behaviour, generally peaking in the mid-frequency range. Notably, the Noise Reduction Coefficient ranged between 0.1510 and 0.4786 across different configurations. Peak absorption was observed between 630 Hz and 1250 Hz for most configurations, with particular structures achieving coefficients as high as 0.99. The number of perforations, hole diameter, and panel thickness played crucial roles in influencing the sound absorption properties, allowing for tailored acoustic solutions. Combining polyurethane foam and 3D-printed perforated panels provides a promising approach for efficient sound absorption for a specified frequency range. This study offers a comprehensive understanding of the influence of structural parameters on sound absorption capabilities, laying the groundwork for optimized, application-specific acoustic solutions.