声波在纤维间存在粘结作用的纤维性吸声材料中的传播

Sound propagation in fibrous absorbing materials with glue effect

摘要:

赵松龄教授根据纤维无规分布的假定，从微观的纤维散射过程出发，借助严格的统计力学方法，考虑纤维本身的振动以及温度变化的影响，导出纤维性吸声材料的唯象模型。但是，这个模型的计算值与实测数据之间仍有一定差异。这些差异随着频率的提高而增大。其原因可能是没有考虑实际材料中纤维间的粘结作用。 考虑纤维间的粘结作用，引入等效容重的表述，得到改进的纤维性吸声材料的唯象模型。实例分析表明，由改进模型计算的理论值与测量数据吻合更好。应用改进模型讨论材料粘结强度、容重、纤维半径和厚度等参数对其声学性能的影响，所得结果与大量纤维吸声材料的实测分析结论完全一致。

Abstract:

Two equivalent formulations for the effective density and the effective bulk modulus of fibrous materials were derived from the microscopic scattering process of the filaments according statistical consideration by Zhao Songling. Then there are some difference between its theoretical results and experimental data. This difference will increase with sound frequency increases. Its cause maybe lay in the glue effect. Considering glue effect and introducing definition of equivalent volume mass, the improvement equivalent formulations were proposed, and an experimental examination is discussed also. Theoretical results are in better agreement with the experimental data. The effects of glue, volume mass, fibrous radius and thickness on acoustic properties were discussed using the improvement equivalent formulations. The analytic results are perfectly agreement with the conclusion from a large number of measurement data on acoustic properties of fibrous absorbing materials.