周向导波在不同连续性条件多层圆筒中的传播

Guided circumferential waves in a multi-layered thick-walled hollow cylinder with different continuous conditions

通过对多层厚壁圆筒中周向导波频散曲线研究,发现周向导波在多层圆筒中传播时,会发生明显的频散现象和模态干涉现象,第1阶模态在高频时接近于无频散的Rayleigh面波。通过对不同连续性条件的多层筒与单层筒的频散曲线比较,以及筒的层数对频散曲线的影响,都充分说明了检测层间界面缺陷的周向导波应该集中在低阶模态上。最后对不同连续性条件多层筒的位移研究,最终推断出第2阶模态具有在层间界面附近集中能量的特征,可应用于层间界面缺陷的周向导波无损检测技术中。

The guided circumferential wave propagation in a multi-layered thick-walled hollow cylinder is investigated.By the study of the dispersion curves of the guided circumferential waves,the phenomena of the frequency dispersion and mode interactions are found.The first wave mode will approach to the Rayleigh wave when the frequency tends to infinity.Through the comparison of the dispersion curves between TSST,TWST,STST,SIST and SOST,and by considering the layer number of cylinder,it is found that the lower modes are useful to the non-destructive detection of the interfacial surface defects.By the study of displacement curves with different continuous conditions,it is further concluded that the second wave mode has larger energy distribution near the interface,and therefore it can be used for the non-destructive detection of the interfacial surface defects.