An Optimization-Driven Design Scheme of Lightweight Acoustic Metamaterials for Additive Manufacturing

Simultaneously, reducing an acoustic metamaterial’s weight and sound pressure level is an important but difficult topic. Considering the law of mass, traditional lightweight acoustic metamaterials make it difficult to control noise efficiently in real-life applications. In this study, a novel optimization-driven design scheme is developed to obtain lightweight acoustic metamaterials with a strong sound insulation capability for additive manufacturing. In the proposed design scheme, a topology optimization method for an acoustic metamaterial in the acoustic-solid interaction system is implemented to obtain an initial cross-sectional topology of the acoustic microstructure during the conceptual design phase. Then, in the detailed design phase, the parametric model for a higher-dimensional design is formulated based on the topology optimization result. An adaptive Kriging interpolation approach is proposed to accurately reformulate a much easier surrogate model from the original parameterization formulation to avoid repeating calls for nonlinear analyses in the 3D acoustic-structure interaction system. A surrogate model was used to optimize a ready-to-print acoustic metamaterial with improved noise reduction performance. Experimental verification based on an impedance tube is implemented. Results demonstrate characteristics of the devised metamaterial as well as the proposed method.