Rapid additive manufacturing of optimized anisotropic metaporous surfaces for broadband absorption

Porous materials and metamaterials play a key role in sound absorbing insulation solutions acoustics. With the growing interest additive manufacturing techniques, recent work has focused on printing of porous resonant structures for acoustic purposes. Usual metaporous surfaces/interfaces are generally built by periodically inserting elements an existing layer. This complex process can be significantly simplified using which also eases design optimization surface. In this work, properties surface controlled simple geometric parameters defining both anisotropic layer shapes resonators. Hence, we focus optimizing split-ring resonators embedded micro-treillis layer, single part techniques. A finite-element method together with Bloch wave decomposition provides numerical model used to predict reflection absorption coefficients under normal incidence. The then optimized non-linear minimization techniques maximize absorption. An optimal is 3D printed fused-deposition modeling, its measured impedance tube. measurements good agreement predicted broadband coefficient. demonstrates benefits designing surfaces.