Acoustical Properties of Homogeneous, Isotropic Rigid Tiles and Flexible Blankets
Acoustical Properties of Homogeneous, Isotropic Rigid Tiles and Flexible Blankets
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均质、各向同性的刚性瓷砖和柔性毯子的声学特性
DOI：
10.1121/1.1916521
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发表时间：
1947
影响因子：
2.4
通讯作者：
L. Beranek
中科院分区：
文献类型：
--
作者：
L. Beranek
本文介绍了刚性吸声砖和柔性吸声毯的研究。结果表明，两种波通过材料传播-一种主要是空气传播，另一种主要是结构传播。根据样品的密度、空气和材料骨架的体积弹性系数、孔隙率、空气流动阻力、纤维间摩擦阻力和结构因子的知识，可以计算出这些波中的每一个的传播常数。实验结果表明，该理论是有用的，在整个可听频率范围内计算的性能的灵活，飞机类型的毯子。然而，对于刚性瓷砖，该理论似乎在频率高于1000 c.p.s.时失效。如果流阻高，则其在所有频率下对于具有低流阻的材料失效。实验表明，包层中气体的凝结和稀薄在低频下是等温的，在高频下是等温的。从一种状态到另一种状态的转移在100到2000 c.p.s.地区需要一个更完整的理论来解释热力学和粘性损失对刚性材料传播常数的影响。
Studies on rigid acoustical tiles and soft blankets are described in this paper. It is shown that two waves travel through the material—one primarily airborne and the other primarily structure‐borne. From a knowledge of the density of the sample, the volume coefficients of elasticity of the air and of the skeleton of the material, the porosity, the air flow resistance, the inter‐fiber frictional resistance, and the structure factor, the propagation constants of each of these waves can be calculated. The experimental results indicate that the theory is useful in calculating the performance of the flexible, airplane type of blankets over the entire audible frequency range. For rigid tiles, however, the theory appears to fail at frequencies above 1000 c.p.s. if the flow resistance is high, and it fails at all frequencies for materials with low flow resistance. Experiment shows that the condensations and rarefactions of the gas in blankets take place isothermally at low frequencies and adiabatically at high. The transfer from one state to the other occurs gradually in the 100 to 2000 c.p.s. region. A more complete theory is required to explain the effects of thermodynamic and viscous losses on the propagation constant of rigid materials.