无限长粘弹性圆柱管中轴对称波的传播模式和衰减
Axisymmetric wave propagation and attenuation along an infinite viscoelastic cylindrical tube
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摘要: 在Kelvin-Voigt线性粘弹性模型框架内研究了无限长粘弹性圆柱管中轴对称波的传播和衰减。通过一个复根搜索程序对频散方程的求解得到无量纲化相速度频散曲线和衰减曲线。比较了引入损耗因子后粘弹性圆柱管与弹性圆柱管中轴对称波传播的特性。给出了圆柱管的外内径之比、损耗因子和材料参数对相速度和衰减的影响。分析结果表明与弹性圆柱管相比粘弹性圆柱管中轴对称波的各阶传播模式均存在衰减,高阶传播模式并无严格意义的截止频率。损耗因子对第一阶传播模式的相速度影响很小,而对衰减的影响则比较大,穿孔率对波传播的相速度和衰减有相当大的影响。Abstract: Axisymmetric wave propagation and attenuation along viscoelastic cylindrical tube are investigated within the framework of Kelvin-Voigt linear viscoelastic model. Non-dimensional phase velocity and attenuation of axisymmetric viscoelastic wave propagation are obtained by a complex root searching program. The characteristics of axisymmetric waves propagation are compared between viscoelastic cylindrical tube and elastic cylindrical tube. The influences of porosity and loss factor and material parameters on phase velocity and attenuation are given. The results show that there exist attenuation in all propagation modes along viscoelastic cylindrical tube, and higher-order propagation modes haven't cut-off frequency. Loss factor has little influence on phase velocity of first mode and large influence on attenuation. Porosity has large influence on both phase velocity and attenuation.