Adjustable and extensible hexagonal acoustic metamaterial cell combining multiple parallel Helmholtz resonators with optional apertures

• Published in: Journal of mechanical science and technology Vol. 37; no. 12; pp. 6385 - 6403
• Main Authors: Yang, Fei, Bi, Shaohua, Shen, Xinmin, Yang, Xiaocui, Wang, Xinqing, Zhang, Xiangpo, Xue, Jinhong, Zhang, Xiaonan, Yin, Qin, Dai, Juying, Peng, Wenqiang, Zhu, Jingwei, Ren, Junhong
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society of Mechanical Engineers 01.12.2023; Springer Nature B.V; 대한기계학회
• Subjects: Absorptivity; Acoustic absorption; Acoustic noise; Acoustic properties; Acoustics; Apertures; Artificial neural networks; Chambers; Computer simulation; Control; Dynamical Systems; Engineering; Finite element method; Frequency ranges; Helmholtz resonators; Industrial and Production Engineering; Mechanical Engineering; Metamaterials; Noise pollution; Noise reduction; Original Article; Permutations; Sound pressure; Vibration; 기계공학; Acoustic finite element simulation; Hexagonal acoustic metamaterial cell; Artificial neural network; Acoustic absorption mechanism; Variable frequency ranges; Tunable acoustic absorption performance
• ISSN: 1738-494X; 1976-3824
• DOI: 10.1007/s12206-023-1113-2

To prevent noise pollution, a hexagonal acoustic metamaterial cell combining multiple parallel Helmholtz resonators with optional apertures is proposed. There were 6 trapezoidal chambers and 6 triangular chambers, and each front panel had 6 different apertures, which meant that there were 6 12 = 2176782336 possible permutations. The distribution of sound pressures obtained by acoustic finite element simulation revealed the acoustic absorption mechanism, which provided effective guidance to alter the absorption capacity. For certain scenarios, the acoustic absorption performance was optimized by the joint combination of artificial neural network and acoustic finite element simulation. Through manufacturing and testing the sample, actual average acoustic absorption coefficients were achieved at 0.6733, 0.7296, 0.8785 and 0.7065 for the target frequency ranges 350–950 Hz, 400–1000 Hz, 500–800 Hz and 350–700 Hz, respectively, with total thickness 40 mm. The tunable acoustic absorption property proved that the hexagonal acoustic metamaterial cell was appropriate for noise reduction with variable frequency ranges.