摘要
发展了一种基于线性粘弹性Kelvin-Voigt模型的二维解析理论,分析声波垂直入射情况下含有周期分布圆柱形空腔的吸声覆盖层的反声和吸声特性。将覆盖层单元近似为粘弹性圆柱管,导出轴对称波的特征方程。再利用前后界面的边界条件得到这些轴对称波的共振频率和覆盖层的反射系数公式。根据理论模型计算了刚性背衬下某种材料吸声覆盖层的低频吸声性能。计算结果表明:(1)材料损耗因子越大吸声系数越大,但吸声峰值频率基本上不变,(2)覆盖层越厚吸声峰值频率越低, (3)穿孔率越小吸声峰频率越高,吸声系数峰值越大。
A two-dimensional analytic model based on linear viscoelastic Kelvin-Voigt model has been established for analyzing the reflection and absorption from a coating containing periodic cylindrical holes at normal incidence. Approximating the unit of coating as hollow viscoelastic cylindrical shell, an eigen equation of the axisymmetric waves is derived. Using the boundary conditions of the front and back boundaries the expressions of resonance frequencies and reflection coefficients of coating are given. The anechoic performance at low frequencies and rigid backing has been calculated by derived formulae. The calculated results show that (1) The larger the material losses, the larger is the absorption coefficient. But the frequencies of peaks of absorption coefficient are nearly inrariable. (2) The thicker the coating, the lower is the frequencies of peaks of absorption coefficient. (3) The smaller the porosity, the higher are the frequencies of peaks of absorption coefficient and the larger is the peak of absorption coefficient.
出处
《声学学报》
EI
CSCD
北大核心
2005年第4期289-295,共7页
Acta Acustica
