一种填充空心玻璃微珠的粘弹性聚合物声学特性研究

Sound attenuation by viscoelastic polymer containing hollow glass microspheres

采用多重散射法,通过微珠周期分布简化模型分析了填充空心玻璃微珠的粘弹性聚合物板的声衰减性能。不同空心微珠填充分数下的理论计算结果均与Baird等人的实验测试结果基本吻合,说明了文中所采用的模型和算法是有效的。采用严格的Mie散射理论,分析了单个空心玻璃微珠在聚合物中的Mie散射特性,结果表明文中分析频率远低于空心玻璃微珠的共振频率,微珠在该频段主要通过调节材料等效阻抗和耗散来提高复合材料的声衰减,与相同厚度不含空心玻璃微珠聚合物板的声衰减相比,复合材料声衰减有很大提高,且声衰减性能随微珠填充分数的增加而逐步增强。

Using the multiple scattering method,the sound attenuation by viscoelastic polymer containing hollow glass microspheres is investigated.A medium having a periodic microsphere distribution is used to model the acoustic propagation through an equivalent composite having random microsphere distribution.The theoretical results for various composite materials with different filling fraction of microspheres are in good agreement with the experimental data of Baird et al,which shows the validity of the model and the computation method.Then,the Mie scattering of a single microsphere is analyzed by reference to the ele鄄ments of the scattering matrix.The results show that the investigative frequency is far below the resonant frequency.Here the sound attenuation by composite polymer is mainly enhanced by the equivalent acoustic impedance and the dissipation adjusted by the microsphere.Compared with pure polymer,the transmission loss of the composite material is much enhanced,and the transmission loss increases with the filling fraction of the microspheres.