Fabrication, sound absorption simulation and performance optimization of multi‐layer gradient fiber‐based composites.

Noise reduction with materials of finite thickness has been a hot research topic. In this study, multi‐layer gradient fiber‐based composites integrating porous, resonant and damping structures were prepared for efficient sound absorption. Here, the effects of composite structure, fiber‐based thickness and micro‐perforated membrane fabric (MPMF) structure on the sound absorption of the composites were investigated. From the results, the sound absorption band of the composite can be effectively tuned by adjusting the structure of the MPMF or the thickness of the fiber‐based. In addition, the established acoustic model can accurately predict the sound absorption performance of the structure. It is worth mentioning that the gradient structure optimized by the algorithm exhibits broadband sound absorption (noise reduction coefficient of 0.42) and thin feature (thickness of 0.9 cm). Moreover, the medium and low frequency sound waves can be propagated and absorbed more easily by optimizing the structure of the composite. This work provides a reference for the preparation of multi‐layer gradient sound‐absorbing structures and the design of acoustic products in a specific frequency range. [ABSTRACT FROM AUTHOR]