Revision as of 09:13, 1 July 2024

Abstract

Recent developments in acoustic metamaterials have been focused on broadening the attenuating bandwidth features towards lower frequency ranges, well below 1000 Hz, as well as tackling manufacturing issues. In this context, a multi-resonant layered acoustic metamaterial (MLAM) was proposed as a practical realization for addressing both challenges. The MLAM’s layered-based design makes it amenable to large-scale manufacturing and the periodic features of each layer enable the application of computational homogenization models to characterize the sound transmission loss (STL) response. Combining these models with optimization techniques allows to determine realistic MLAM designs that trigger multiple resonances in broad frequency ranges. By exploiting coupling mechanisms these resonances translate into multiple STL peaks that produce a broadband continuous frequency range of attenuation, i.e., without transmission peaks in-between. In this work, the proposed computational homogenization model is presented and applied to the design of different MLAM configurations. The goal is to assess the influence of the number of coupled resonating layers in the STL response of the whole MLAM panel, in terms of increasing the attenuation intensity and the effective frequency bandwidth. The results demonstrate the STL enhancements features obtained from exploiting coupling mechanisms, compared to other acoustic metamaterial configurations based on local resonance phenomena. In this context, the proposed MLAM technology exhibits a great potential to provide an efficient, easy-to-manufacture solution to the sound insulation problem at low frequency ranges