具有特定边界的粘弹性圆柱管中波的传播和衰减

本文在线性粘弹性模型框架内研究了一定边界条件下无限长粘弹性圆柱管中轴对称波的传播和衰减.在Ivasson 和Karasalo的方法的基础上,发展了一个自适应绕数积分求根方法.利用该方法得出了粘弹性圆柱管的无量纲化相速度频散曲线和衰减曲线.然后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.给出了圆柱管的一些参数对相速度和衰减的影响.

Wave Propagation and Attenuation in a Viscoelastic Cylindrical Tube with Specific Boundary

Axisymmetric wave propagation and attenuation along viscoelastic cylind rical tube for a given boundary are investigated within the framework of linear viscoelasticity.Based on the method of Brazier-Smith and Scott,an adaptive windi ng number integral method for root-finding is developed.Non-dimensional phase ve locity and attenuation of axisymmetric viscoelastic wave are obtained by the met hod.The characteristics of axisymmetric wave propagation are compared between th e viscoelastic cylindrical tube and the elastic cylindrical tube.Then,the influe nces of some parameters on phase speed and attenuation are analyzed. The results show that there exist attenuation in all propagation modes,and strictly speakin g,higher-order propagation modes haven't cut-off frequency. Loss factor has litt le influence on phase velocity of the propagation mode of the lowest order,but l arge influence on its attenuation.The ratio of external radius to internal radiu s has large influence on both phase velocity and attenuation.