混合谱二维傅里叶变换法识别兰姆波模式  

Modes Recognition of Lamb Wave by Means of a Mixed-Spectral Two-Dimensional FFT

作　　者：卢超[1,2] 黎连修[1] 涂占宽[1] 

机构地区：[1]铁道科学研究院金属及化学研究所,北京100081 [2]南昌航空大学无损检测技术教育部重点实验室,南昌330063

出　　处：《无损检测》2008年第11期809-812,共4页Nondestructive Testing

基　　金：铁道部科技研发计划项目(2007G040);无损检测技术教育部重点实验室开放基金(ZD200729004)

摘　　要：在分析二维傅里叶变换原理的基础上,将快速傅里叶变换(FFT)和自回归(AR)参数估计相结合,采用混合谱二维傅里叶变换方法,对铝板中的兰姆波模式进行识别。试验结果表明,与二维快速傅里叶变换相比,混合谱估计方法能精确检测多模式超声兰姆波相速度,对兰姆波模式识别力大大提高。混合谱二维傅里叶变换方法在超声导波检测研究中具有广泛的应用前景。Based on the analysis of two-dimensional Fourier transform method （2-D FFT）, a mixed-spectral estimation was proposed combined with FFT and AR model for the recognition of Lamb wave propagating model in aluminum plates. Experimental results showed that the mixed spectral estimation could detect the ultrasonic phase velocity of multi-mode Lamb wave accurately, compared with the conventional two-dimensional Fourier trans^orm methods, the resolving power of the new method was highly increased. The mixed-spectral estimation methods could be widely used for development of ultrasonic guided wave testing.

关 键 词：兰姆波检测 频散 二维傅里叶变换 

分 类 号：TG115.28[金属学及工艺—物理冶金]