传递矩阵-驻波管法研究材料隔声性能

Study on Acoustic Transmission Loss of Materials with Transfer Matrix-Impedance Tube Methods

从材料内部声场变化以及材料外部声场变化2个方面研究了材料的隔声性能。首先利用传递矩阵法详细分析了层合复合材料的隔声特型,理论推导了垂直入射平面波声压透射系数和隔声量随密度、声速、厚度以及频率变化的关系式。从实际测试的角度介绍了对材料进行隔声量测试的四通道传声器驻波管法原理,并对其使用的数学计算公式进行了推导。在理论与实际的基础上,分别对一定厚度的钢板和复合材料进行了理论仿真计算和实验测试,结果表明二者基本吻合。

The acoustic transmission loss of materials is studied from the sound field changes of material internal and external parts. At first the sound transmission characteristics of laminated composite materials are analyzed by transfer matrix method. The formula of sound pressure transmission coefficient ＆ acoustic transmission loss with the density, sound velocity, thickness and frequency changes are derived in normal incidence plane wave. Then the 4-channel impedance tube with single-sensor for testing transmission loss（TL） of acoustic materials is introduced, and the math-formulas for calculating is also derived. At last, the theory simulation calculation and experimental test are conducted with certain thickness plate and laminated composite materials. The results show that the experimental results accord well with the theoretical ones.