Sound transmission loss of periodic Mindlin plates with non-uniformly spaced mass attachmentsa)

Andrew J Hall; Vladislav Sorokin; Mehrdad Aghamohammadi; George Dodd; Gian Schmid; Yi Yang; Brian Mace

doi:10.1121/10.0025386

Sound transmission loss of periodic Mindlin plates with non-uniformly spaced mass attachmentsa)

J Acoust Soc Am. 2024 Mar 1;155(3):2199-2208. doi: 10.1121/10.0025386.

Authors

Andrew J Hall¹, Vladislav Sorokin¹, Mehrdad Aghamohammadi¹, George Dodd¹, Gian Schmid¹, Yi Yang², Brian Mace¹

Affiliations

¹ Acoustics Research Centre, Department of Mechanical and Mechatronics Engineering, University of Auckland, Auckland 1142, New Zealand.
² State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, China.

PMID: 38517262
DOI: 10.1121/10.0025386

Abstract

The sound transmission loss (STL) of wall partitions, especially in the coincidence region, is investigated. A Mindlin plate with periodically attached masses in a periodic "supercell" pattern is analyzed theoretically and experimentally for sound attenuation. Modeling the masses as points, analytical expressions for predicting the dispersion relation and frequency bandgaps of the plate are developed. The results show that varying the distances between the masses or the masses themselves can lead to the emergence of additional lower-frequency bandgaps and slightly decrease the bandwidth of the primary complete bandgap. Additionally, a triangular periodic pattern of point masses can provide a larger complete bandgap than the conventional rectangular pattern. The results are validated by numerical analyses using the wave and finite element method. Experimental testing is conducted on large-scale plates (2.4 m × 1 m) with periodically attached masses under diffuse field conditions, demonstrating the benefits of utilizing multiple scattering to increase the STL in the coincidence region of the bare plate. The proposed approach is seen to significantly increase the STL of wall partitions in the coincidence region and provides insights into the fundamental principles of sound and vibration attenuation in complex structures based on multiple scattering.