《孔中介质对厚微穿孔板吸声性能的影响》

典型的微穿孔板为孔径与板厚均小于1mm的金属或塑料板，这些极薄的板材因其强度低，通常不适用于民用，也因此使微穿孔板这一良好的吸声共振结构的应用范围受到局限。本文以厚度为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，用阻抗管法测量吸声系数，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。

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

MPPs are typically made of a thin metal or plastic panel. However, thin limp panels are generall not suitable as an interiornish of room walls because they do not have sucient strength, which prevent spractica lapplication of MPPs as an interiornish of roomwalls. When we put the air, water, polyvinyl alcohol and wool fiber into the pores of the thick microperforated panel respectively and the epoxy resin panel have a porosity of 7%, 10mm thick and the pore is 1mm in diameter. Measurements of the sound absorption characteristics of microperforated panel with those above material have been carried out in the Pulse 3560 and 4206 made in B&;K company. The result show that the absorption coefficient of sound is better when the wool fiber’s number is 53 per pore and the depth of the back air cavity is 20mm than air in its holes. The peak value of sound absorption coefficient is about 0.94 when the resonance frequency is about 956, the frequency from 612Hz to 1600Hz all have the absorption coeifficien above 0.5.