带形介质内SH型导波对圆柱孔洞的动力分析

弹性板壳的反平面运动中由缺陷引起的应力集中问题可以按照带形介质中圆柱孔洞对SH型导波的散射问题来分析。首先,构造带形介质中相容导波的形式,即其满足上、下边界应力自由条件。之后,由波函数展开法给出圆柱孔洞散射波的级数表示,根据累次镜像叠加的方法构造由上、下边界反射所形成的相容的散射导波。最后,给定入射导波,由圆柱孔洞边界应力自由的条件来定解波函数级数的系数。数值算例求解了特定导波对圆柱孔洞的散射,给出了圆柱孔洞边沿的动应力分布,讨论了导波阶数、频率以及孔洞位置的影响。

DYNAMIC ANALYSES OF SH GUIDED WAVES BY CIRCULAR CYLINDRICAL CAVITY IN AN ELASTIC STRIP

Dynamic stress concentrations during anti-plane motion caused by a defect an elastic shell can be treated as a scattering problem of a circular cylindrical cavity with SH guided waves in an elastic strip for the purposes of analysis. Firstly, a compatible guided wave is formulated in the elastic strip, which satisfies stress free conditions in upper and lower bounds. Secondly, the scattering of waves around a circular cylindrical cavity is expressed as series form by the employed wave function expansion method, and compatible scattering guided waves resulting from the reflection of waves off the bounds of the elastic strip is constructed by repeated image superposition. Lastly, the coefficients of the wave function expansion are determined based on the stress free condition of circular cylindrical bounds with pre-given incident guided waves. Numerical calculating examples are presented to solve scattering around a circular cylindrical cavity with a given SH guided wave, to describe dynamic stress distribution at the edge of a cavity, and to discuss influences of guided orders, frequencies, and positions of cavity.