Measuring Effective Parameters of Composite Acoustic Metamaterials Using Impedance Tube

Abstract

本文在考虑了阻抗管中存在多重反射的情况下，利用传递函数法优化得出了样品的透射系数和反射系数，从而获得声学超材料有效材料参数。在比较了不同阻抗管算法实验结果之后，可以发现本文提出的新测量方法和仿真结果有着很好的吻合，可以非常准确的获得材料的有效参量。新发展的测量方法，对消声端的消声吸声要求不高，可以测量不吸声的材料，扩展了阻抗管测量的适用范围，对声学超材料的设计和相关应用都有着一定价值。 A new experimental method is developed to precisely measure the effective density and bulk modulus using impedance tube. Considering the multiple reflections on multi-surfaces, a new al-gorithm using transfer matrix method is considered to obtain the transmission and reflection coefficient through a lossless sample and the corresponding effective parameter can thus be retrieved. Good consistence can be found between simulations and experiments. Having little impact from the absorbing property of the termination, our newly developed method has advantages to traditional impedance tube methods and can benefit the development of acoustic metamaterials.