基于FFT和小波包变换的电磁声发射信号处理  

Signal Processing of Electromagnetically Induced Acoustic Emission Based on FFT and Wavelet Packet Transform

作　　者：张闯[1] 刘素贞[1] 杨庆新[1,2] 金亮[1] 冯玲玲[1] 杨素梅[1] 

机构地区：[1]河北工业大学电磁场与电器可靠性省部共建重点实验室,天津300130 [2]天津工业大学,天津300160

出　　处：《电工技术学报》2010年第4期24-28,共5页Transactions of China Electrotechnical Society

基　　金：河北省自然科学基金资助项目(E2007000067)

摘　　要：电磁声发射技术是一种新型的无损检测技术,对金属部件进行电磁加载会在裂纹处激发出声发射信号,利用这一现象可以实现对金属材料的无损检测。本文分析了电磁声发射技术的基本原理与实现过程,采用快速傅里叶变换对大量实验信号进行时频分析,验证了带裂纹金属板能够产生电磁声发射现象,并基于小波包变换和能量分布情况得出了金属板有无裂纹的特征判据,为电磁声发射技术的工程应用打下了良好的基础。Electromagnetically induced acoustic emission （EMAE） technique is a new nondestructive testing （NDT）. It did nondestructive detection with the effect of dynamic electromagnetic loading to generate a stress field stimulating stress waves from the defects. This paper analyzes the principle and implementation procedure of the EMAE. It verifies that it could excite the phenomenon of EMAE in the metal plate with the crack by means of time-frequency analysis to the experimental signal by using fast Fourier transform （FFT）. A criterion of the metal plate with the crack based on the wavelet packet transform and energy partition is obtained. This work laid a good foundation for the engineering application of EMAE.

关 键 词：电磁声发射 信号处理 快速傅里叶变换 小波包变换 

分 类 号：TM15[电气工程—电工理论与新技术]