一、引言只有在少数比較簡单的介貭結构中,弹性波的传播問題可以自理論上予以解答;实际中所遇到的問題,往往要复杂得多。卽使是最簡单的問題,理論的計算也常常很繁复。因此如何利用簡便的模型来解决弹性波的传播問題,是很多人所感到兴趣的。 I. INTRODUCTION Only in a few simple structures, the propagation of elastic waves can be answered theoretically theoretically; the problems encountered in practice are often much more complex.卽 is the simplest question, and theoretical calculations are often complicated. So how to use the simple model to solve the propagation of elastic wave is a lot of people are interested.