孔中介质对厚微穿孔板吸声性能的影响

The Influence of Pore's Media on Sound Absorption Characteristics of Thick Microperforated Panel

以厚度为10mm的环氧树脂基厚微穿孔板为研究对象,分别选择空气、水、聚乙烯醇、羊毛纤维作为孔中介质,研究各种介质对微穿孔板吸声性能的影响。结果发现,通过在孔中加入纤维材料可以在一定程度上弥补因材料厚度增加而导致的吸声性能的减弱。当平均每孔中穿入53根羊毛纤维,后空腔深度为20mm时,厚微穿孔板共振吸收频率为956 Hz,峰值吸声系数可达0.94。有效吸声频带范围为612Hz-1600Hz以上。

Micro-Perforated Panels （MPPs） are usually made of thin metallic or plastic sheets. whose thickness is less than 1 mm. However, such thin panels are not suitable for civil use because they do not have sufficient strength and rigidity. Thus, application of MPPs is limited. In this paper, epoxy resin MPPs with 10mm thickness and lmm pore diameter are studied. Air. water, polyvinyl alcohol and wool fiber are respectively considered to be the media in the pores. Sound absorption is measured with impedance pipe method. Results show that the sound absorption ability of the thick panel can be improved by inserting fiber materials into the pores. Peak value of the absorption coefficient of sound can reach 0.94 when the wool fiber＇s average number is 53 per hole ,the depth of the back cavity is 20mm , and the resonance frequency is about 956 Hz, The absorption coeifficient can exceed 0.5 in the frequeney range from 612Hz to 1600Hz.