Acoustic metamaterial samples preparation for impedance tube measurements—The influence of different 3D printing techniques and mechanical post-processing on the simulation compliance

Abstract

Prototyping of acoustic metamaterials frequently involves the use of additive manufacturing techniques. It offers the best price and the option for complex structure production, which is beneficial in the R&D process. Previously, some differences in acoustic metamaterial sound absorption measurement dispersions regarding using 3D printing techniques for sample preparation were noted. The sound absorption sensitivity on different printing settings or materials is usually omitted. The paper will present the research on the impedance tube measurements of absorbing metamaterial manufactured with different 3D printing methods and post-processed with mechanical and chemical treatment. Two approaches to metamaterial construction were analyzed in the current study—the single-solid metamaterial and the structure divided into parts, where the influence of assembly methods was investigated. To achieve the best compatibility with FEM or TMM modeling results, different post-processing techniques were involved, such as drilling, grinding, and sealant use. The presentation will describe the valuable paths used in sample preparation to achieve better compatibility between the measurements and simulations. The need for a comprehensive part preparation description in metamaterials research and papers will be discussed. [Work funded and supported by the Polish Government, National Centre of Research and Development, agreement no. LIDER/11/0065/L-12/20/NCBR/2021.]