中文摘要：

利用傅里叶变换、短时傅里叶变换及希尔伯特一黄变换对激光激发的Lamb波进行模式识别，并对分析结果进行比较、分析。结果表明：傅里叶变换和短时傅里叶变换只能识别出能量较大的模式；而利用希尔伯特一黄变换可同时识别出能量较大和能量较小的模式。该研究为激光超声检测技术提供了研究基础。

英文摘要：

The modes of laser generated Lamb waves are able to be recognized by different kinds of spectrum analytical methods such as fast fourier transform （FFT）, short time fourier transform （STFI＇） and Hilbert-Huang transform （HHT）. It can be found that by FFT and STFT, only the powerful mode can be recognized, however, by HHT, both of powerful and weak modes can be recognized. The study provides basic research for laser ultrasonic detection.