固体火箭发动机多层结构壳体的导波频散特性分析

Analysis of dispersive characteristics of guided wave in multi-layered structure of solid rocket motor shell

利用导波对固体火箭发动机的多层结构壳体进行检测是一种很有前景的无损检测方法。本文应用全局矩阵法,推导了多层结构壳体的导波频散方程,并分别针对固体火箭发动机4种不同层数的壳体导波频散曲线进行了求解,发现当结构层数和第一层厚度增加时,各模式曲线的间隔缩小,曲线数目增加,并有向零频方向靠拢的趋势。同时研究了粘接质量变化对频散特征的影响,随着胶层质量相对变差,频散曲线总体向低频漂移。

The guided wave testing is a kind of promising method for the testing of multi-layered Structure of solid rocket motor. This paper makes use of the global matrix method, inferred the dispersion equations of multi-layered structure shell. The dispersion curves of four different numbers of layers of the shell structure are computed. It is shown that with the increase of number of layers and the first layer＇s thickness, the distance between different model curves will decrease, the number of curves increase, and the curves move close to zero frequency. This paper also studies the influence of layer＇s glue quality for dispersion curve, it＇s found that the curves will move to low frequency when the glue layer become worse.