说明：  本文主要阐述了谱分析方法和相关分析方法在声发射信号分析中的应用，给出了谱分 析和相关分析的基本原理，并分别举例子做了分析讨论。
(This paper expounded the method of spectrum analysis and correlation analysis method in acoustic emission signal analysis, gives the spectral analysis and correlation analysis of the basic principles and examples to do, respectively, analyzed and discussed.)