PROCEEDINGS of the 22 nd International Congress on Acoustics Materials for Noise Control: Paper ICA2016-326 Experimental study on sound performance of microperforated panel with membrane-type acoustic metamaterials composite structure Xiao-ling Gai (a), Xian-hui Li (b), Tuo Xing (c), Bin Zhang (d}, Jun-juan Zhao (e} (a) Beijing Municipal Institute of Labor Protection, China, gxldynmg@163.com (b) Beijing Municipal Institute of Labor Protection, China, lixianh@vip.sina.com (c) Beijing Municipal Institute of Labor Protection, China, xingtuo1991@163.com (d) Beijing Municipal Institute of Labor Protection, China, zhangbin815@hotmail.com (e) Beijing Municipal Institute of Labor Protection, China, junjuanzhao@sina.com Abstract Microperforated panel (MPP) absorbers have been widely used in noise reduction and are regarded as a promising alternative to the traditional porous materials. However, the absorption bandwidth of a single-layer MPP is insufficient to compete with the porous materials. In order to improve the sound absorption ability of the single-layer MPP, MPP with membrane-type acoustic metamaterials composite structure is introduced. Sound absorption properties of the MPP with membrane-type acoustic metamaterials composite structure are studied by the impedance tube experiment. Results show that Membrane cell can change the sound absorption of MPP by introducing additional absorption peaks and valleys. Membrane cell and mass blocks mainly increase the normalized surface resistance of MPP with membrane-type acoustic metamaterials composite structure. Excellent performance of sound absorbing structure will be obtained by rational design of microperforated plate, the size of film cell, the number, size and position of mass blocks. Keywords: Microperforated panel, membrane-type acoustic metamaterials, Sound absorption coefficient, Sound absorption peak
22 nd International Congress on Acoustics, ICA 2016 1 Introduction In recent years, noise control has received much attention for improving living environments. A microperforated panel (MPP) absorber has become widely known as the most attractive alternative for the next generation sound absorbing material [1]. The MPP is first proposed by Maa, who has established its theoretical basis and design principle [2-4]. The MPP absorber is a thin panel or membrane less than 1mm thick with perforation of less than 1% perforation ratio with air-back cavity and a rigid backing [5]. The fundamental absorbing mechanism of the MPP absorber, which is typically backed by an air cavity and a rigid wall, is Helmholtz-resonance absorption [6]. This type of absorption is mainly due to frictional loss in the air flow of the apertures [6]. With the rapid development of processing technologies and computational methods, micro-perforated panel sound absorption theory has also been further development [7-9]. But usually the single-leaf MPP sound absorbing structure is generally only one resonance absorption peak and the sound absorption bandwidth is usually limited to about two octaves [2-4]. In order to heighten the absorption property of MPP, Maa has proposed a doubleleaf MPP backed by a rigid-back wall with an air-cavity [10]. Recently, Asdrubali and Pispola have studied this type of absorber for its application to noise barriers [11]. This absorber is intended to produce two resonators so that a broader absorption frequency range can be obtained. The acoustical properties of a structure composed of two parallel MPP with an aircavity between them and no rigid backing is studied numerically by Sakagami [12]. Qian et al have investigated the acoustical properties of MPP with ultra-micro perforations based on MEMS technology [13]. Results show that better absorption capability can be given with MPP by using an ultra-micro perforation [13]. Liu and Herrin have study the sound attenuation performance of MPP with adjoining air cavity [14]. The resulting sound pressure fields indicated that partitioning the adjoining air cavity increase the overall sound attenuation due to the MPP by approximately 4d B [14]. Wang and Huang have investigated the acoustic properties of parallel arrangement of multiple MPP absorbers with different cavity depths [15]. Compared with single MPP absorber, the absorber array requires lower acoustic resistance for good absorption, and the resonance frequencies shift due to inter-resonator interactions [15]. Tao et al have studied the sound absorption of a finite micro-perforated panel backed by a shunted loudspeaker [16]. The results show that the composite absorber is more effective than the traditional MPP absorbers especially at the low frequency when there is a length constraint thanks to the resonance absorption provided by the shunted loudspeaker [16]. We have the sound absorption of a composite MPP sound absorber with membrane cells [17]. Experimental results show that the MPP with membrane cell can provide more absorption than the single-leaf MPP absorber. In this study, comprehensively considered the characteristics of MPP and metamaterial, composite structure of MPP with membrane-type acoustic metamaterial is proposed. Structure of this paper will be arranged as follows: In Section 2, sample of the MPP with membrane cell (MPPM) will be shown. In Section 3, the sound absorption performance of MPPM will be studied. Finally, the conclusions will be given in section 4. 2
22 nd International Congress on Acoustics, ICA 2016 2 Sample construction Figure.1 shows a sketch of the manufacturing process of a composite structure of MPP with membrane-type acoustic metamaterial. MPP used is aluminium panel 100mm in diameter. Thickness, aperture and porosity for the MPP are 0.8mm, 0.8mm and 2% respectively. The membrane the latex film used in the production of a balloon. First membrane is fixed to steel ring by glue, then steel ring are attached to MPP by plastics glue. Last, the mass are attached to membrane cell. Figure 1: The manufacturing process of MPP with membrane and mass 3 Impedance tube experiments Figure.2 shows experimental samples of MPP with membrane and mass. The sound absorption of the single-leaf MPP with diameter 40mm membrane cell and mass block are shown in Figure 3-5. Figure 3 show that MPP with diameter 40 mm membrane cells have a sound absorption valley at 740Hz. The sound absorption coefficient of valley is 0.05. After increasing a mass block, one sound absorption valley becomes two sound absorption valleys. The valley values are 0.30 and 0.15 at 660 Hz and 860 Hz. After increasing the second mass block, the valley values become 0.55 and 0.27 at 680 Hz and 1120 Hz, respectively. After increasing the third mass block, the sound absorption coefficient is more than 0.5 in the range of 460-1160 Hz. Figure.4-5 depict the measurements results for the normalized surface impedances of the single-leaf MPP and MPP with diameter 40mm membrane cell and mass block. The experimental results indicate that the normalized surface resistance and reactance change a lot. The normalized surface resistance plays main roles still. Figure 2: MPP with membrane cell(40mm) and mass block 3
Resistance Sound absorption coefficient 22 nd International Congress on Acoustics, ICA 2016 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 MPP MPP with d=40mm membrane MPP with d=40mm membrane and one mass MPP with d=40mm membrane and two masses MPP with d=40mm membrane and three masses 0 0 200 400 600 800 1000 1200 1400 1600 Frequency(Hz) Figure 3: Experimental absorption curve of the single-leaf MPP, MPP with diameter of 40mm membrane and mass blocks 10 9 8 7 6 MPP MPP with d=40mm membrane MPP with d=40mm membrane and one mass MPP with d=40mm membrane and two masses MPP with d=40mm membrane and three masses 5 4 3 2 1 0 200 400 600 800 1000 1200 1400 1600 Frequency(Hz) Figure 4: Measured resistance of the single-leaf MPP, MPP with diameter of 40mm membrane and mass blocks 4
Reactance 22 nd International Congress on Acoustics, ICA 2016 5 0-5 -10 MPP MPP with d=40mm membrane MPP with d=40mm membrane and one mass MPP with d=40mm membrane and two masses MPP with d=40mm membrane and three masses -15 200 400 600 800 1000 1200 1400 1600 Frequency(Hz) Figure 5: Measured reactance of the single-leaf MPP, MPP with diameter of 40mm membrane and mass blocks 4 Conclusions In conclusion, present work has been focused on the sound absorption performance of the MPP with membrane-type acoustic metamaterials composite structure by impedance tube experiments. Experimental results show :( 1) Membrane cell can change the sound absorption of MPP by introducing additional absorption peaks and valleys; (2) Membrane cell and mass blocks mainly change the normalized surface resistance of MPP with membrane-type acoustic metamaterials composite structure. Acknowledgments This work was supported by the National Natural Science Foundation of China under Grant No. 11274048, Beijing Natural Science Foundation No.8142016 and 1164013, Innovation team IG201501C1 and Project of innovation of Beijing Academy of Science and Technology PXM 2016-178304-000002, Xicheng Excellent Talents Project No.20150057 and Youth Backbone 201502. References [1] Sakagami, K.; Morimot, M.; Yairi, M. A note on the effect of vibration of a microperforated panel on its sound absorption characteristics, Acoustical Science and Technology, 26(2), 2005, pp 204-207. [2] Maa, D. Y. Theory and design of microperforated panel sound-absorbing constructions, Science, 18, 1975, 55-71. [3] Maa, D. Y. Microperforated-panel wide band absorbers, Noise Control Engineering Journal, 29, 1987, 77-84. 5
22 nd International Congress on Acoustics, ICA 2016 [4] Maa, D. Y. Potential of microperforated panel absorber, Journal of the Acoustical Society of America, 104, 1998, 2861-2864. [5] Sakagami, K.; Morimoto, M.; Yairi, M. Double-leaf microperforated panel space absorbers: A revised theory and detailed analysis, Applied Acoustics, 70, 2009, 703-709. [6] Toyoda M.; Mu, R. L.; Takahashi, D. Tionship between Helmholtz-resonance absorptionand paneltype absorption in finite flexible microperforated-panel absorbers, Applied Acoustics, 71, 2010, 315-320. [7] Fuchs, H. V.; Zha, X.; Drotle, H. D. Creating low-noise environments in communication rooms, Applied Acoustics, 62, 2001,1375-1396. [8] Zha, X.; Fuchs, H. V.; Drotle, H. D. Improving the acoustic working conditions for musicians in small spaces, Applied Acoustics, 63, 2002, 203-221. [9] Maa, D. Y. Absorption limit of MPA, Acta Acustica, 28, 2003, 561-562. [10] Maa, D.Y.; Liu, K. Sound absorption characteristics of microperforated absorber for random incidence, Acta Acustica, 25(4), 2000, 289-296. [11] Asdrubali, F.; Pispola, G. Properties of transparent sound-absorbing panels for use in noise barriers, Journal of the Acoustical Society of America, 121, 2007, 95-100. [12] Sakagami, K.; Morimoto, M.; Koike, W. A numerical study of double-leaf microperforated panel absorbers, Applied Acoustics, 67, 2006, 28-34. [13] Qian,Y. J.; Kong, D. Y.; Liu, S. M.; Sun, S. M.; Zhao, Z. Investigation on micro-perforated panel absorber with ultra-micro perforations, Applied Acoustics, 74, 2013, 931-935. [14] Liu, J. D.; Herrin, W. Enhancing micro-perforated panel attenuation by partitioning the adjoining cavity, Applied Acoustics, 71, 2010, 120-127. [15] Wang, C. Q.; Huang, L. X. On the acoustic properties of parallel arrangement of multiple microperforated panel absorbers with different cavity depths, Applied Acoustics, 130, 2011, 208-218. [16] Tao, J. C.; Jing, R. X.; Qiu, X. J. Sound absorption of a finite micro-perforated panel backed by a shunted loundspeaker, Journal of the Acoustical Society of America, 135(1), 2014, 231-238. [17] Gai, X. L.; Li X. H.; Zhang, B.; Xing, T.; Zhao, J. J.; Ma, Z. H. Experimental study on sound absorption performance of microperforated panel with membrane cell, Applied Acoustics, 110, 2016, 241-247. 6