边界条件对多孔材料声学参数测试的影响研究

多孔材料声学特征参数测试前需要采用机械切割方法和样品容器匹配,然而切割后的材料边缘不能完全和样品容器匹配,因此采用加环的方式进行处理。以三聚氰胺泡沫为例,通过控制测试材料的边界条件,测试材料的流阻率,在软件中选用合适的声学模型计算得出该材料的声学特征参数。最后将阻抗管测试得到的吸声系数与AMDesigner仿真得到的吸声系数进行比较。结果显示,加两个环后仿真得到的值与测试值吻合效果较好,加一个环在低频区吻合效果较好,而直接将切割得到的材料进行测试效果最差。该研究可以为今后的声学材料测试研究提供指导。

Influence research of boundary conditions on acoustic parameters test of porous materials

The acoustical parameters of the porous material require a mechanical cutting method to match the sample container prior to testing,however the edge of the material after cutting cannot be completely matched to the sample container.Therefore,it is processed by adding a ring.Taking melamine foam as an example,by controlling the boundary conditions of the test material and testing the flow resistivity of the material,the acoustic characteristic parameters of the material were calculated in the software with a suitable acoustic model.Finally,the sound absorption coefficient obtained by the impedance tube test was comparedwith that obtained by AMDesigner simulation.The results show that the value obtained by adding two rings was in agreement with the test value.The value obtained by addingone ring was betterin the low frequency region,and thematerial obtained by cutting had the worst test result.It could provide guidance for more accurate testing of the flow resistivity of porous foam in the future.