基于PVDF薄膜的智能材料回声控制实现

提出了用高分子压电材料——PVDF薄膜作为激励声源，将其内嵌于基体材料聚氨酯橡胶中制成具有特殊功能的消声材料。通过声时延的方法，用布置在消声样件前方的两传声器检测出平面入射声波和反射声波，利用压电材料PVDF薄膜的逆压电性能，对其施加具有一定幅值和相位的电压，实现样件材料的声阻抗和介质声阻抗的匹配，以使得反射声波达到最小或零，从而实现回声控制的目的。最后对不同频率的入射声波进行了基于声阻抗管的回声控制实验测试并对结果进行了分析。

Implementation on echo control of smart material based on PVDF film

This paper brings about a new type of macromolecule material, PVDF film used as acoustical source, which is embedded in polyurethane acoustic foam forming a compact arrangement with specific functions. Through ways of delaying in time range, it can distill the incident planar wave and reflected plane wave. The material, PVDF, when given such a voltage with some specific amplitude and phase owned to its piezoelectricity capability that realizes sound impedance matching between the specimen with the medium, can eliminate reflected sound pressure to least or completely. At last active echo control testing and analysis based on impedance-tube is carried on with different incident sound waves in frequency.