Contribution
A Sensitivity Study Approach to Improve the Sound Transmission Loss Performance of Vibro-acoustic Metamaterials with Embedded Helmholtz Resonators
* Presenting author
Abstract:
Acoustic ‘meta-partitions’, which are composed of a partition with periodically attached resonators, exhibit an improved low-frequency sound insulation by introducing a frequency region of superior transmission loss (TL) that exceeds the mass-law TL of a homogeneous partition with equivalent mass. A common resonator design for meta-partitions is a cantilever-type vibro-acoustic metamaterial, which has a simple design for manufacturing and tuning the TL performance. However, this type of metamaterial only achieves a narrowband TL improvement and introduces a frequency band with a TL deficit at higher frequencies. To improve the TL performance of the partition without adding mass, a Helmholtz resonator can be embedded into the cantilever resonator. This work aims to provide a deeper understanding into the design process of meta-partitions with cantilever-Helmholtz resonators by presenting sensitivity study results on the TL improvement and bandwidth through various input design parameters to an analytical model of the meta-partition. The TL of the meta-partition is predicted using the transfer matrix method, where the partition is represented as an effective medium with frequency dependent mass density and bulk modulus. With this work, guidelines on selecting certain values for each parameter are recommended to maximise the performance of this novel meta-partition design.