敷设粘弹性材料的多层吸声模型阻抗匹配

Impedance Matching of Multiple-Layer Absorption Model Covered with Viscoelastic Material

研究敷设粘弹性材料多层结构的阻抗匹配方法对水下目标隐身具有重要意义。文中利用多层介质声传播理论,推导了简洁的任意多层结构模型声场特性计算公式,并结合粘弹性材料的动态特性,应用所推公式计算了水下敷设吸声材料多层模型的声场特性。借助数值分析方法,对多层结构模型各层材料特性阻抗与模型声学性能间的关系进行了仿真,探索利用模型各层特性阻抗设计模型阻抗匹配的方法。通过分析模型各层特性阻抗比例关系对模型声场特性的影响,得出其实现阻抗匹配的最优取值范围。研究结果对设计、选取吸声材料具有重要意义。

The laconic calculating formulae of arbitrary multiple-layer model′s acoustic characteristics was introduced with sound transmission theoretics in multilayer mediums.Taking properties of viscoelastic material in account,the sound absorption characteristics of multiple-layer model covered with viscoelastic material underwater were calculated using formulae deduced.By numerical analysis,the relation between absorption model and material parameters was simulated and the effect of proportion among layers′ natural impedance on acoustic characteristics of sound absorption model was analyzed.The best layer-impedance proportion is gained for meeting the matching need of model input impedance.Then the method of designing sound absorption model by multiple-layer structures each layer natural impedance was studied.The result is of significance to devising sound absorption material and model.