表面裂纹的激光超声可视化兰姆波检测研究  

Surface cracks testing by laser-ultrasonic visualization inspection of Lamb waves

作　　者：李阳[1,2] 杨连杰 孙俊杰 路培鑫[1] 邹云 LI Yang;YANG Lianjie;SUN Junjie;LU Peixin;ZOU Yun(School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,Henan,China;Henan Province Engineering Laboratory for Anti-Fatigue Manufacturing Technology,Zhengzhou 450001,Henan,China)

机构地区：[1]郑州大学机械与动力工程学院,河南郑州450001 [2]抗疲劳制造技术河南省工程实验室,河南郑州450001

出　　处：《声学技术》2020年第2期157-160,共4页Technical Acoustics

基　　金：国家自然科学基金(51705470);河南省重点研发与推广专项(18A460032);河南省高等学校重点科研项目(18A460032)。

摘　　要：兰姆波在板材的缺陷检测中具有重要的地位,但兰姆波在裂纹检测过程的可视化实验研究较少。通过激光超声可视化技术,观察了激光激励出的宽频兰姆波在0.4 mm深、0.2 mm宽的裂纹上的反射和透射现象;并利用带通滤波技术,研究了不同中心频率的兰姆波在裂纹上的散射特性。结果发现:兰姆波在裂纹上发生了模态转换现象,出现了传播速度较快的兰姆波模态;并随着兰姆波频率的增加,反射兰姆波的能量增强。该研究为板中裂纹的兰姆波检测提供了实验参考。Lamb wave plays a significant role in plate defect testing,but the visualized research on Lamb wave scattering at cracks is still not enough.In this paper,the laser-ultrasonic visualization inspection method is used to inspect the reflection and transmission of the laser excited broadband Lamb wave at a crack of 0.4 mm deep and 0.2 mm wide.In addition,the scattering characteristics of Lamb wave with different center frequencies at cracks are studied by band-pass filtering technique.It is found that the mode transformation of Lamb wave occurs at cracks and a mode with faster velocity is found.As the frequency increases,the reflected Lamb wave is getting more energy.This research offers an experimental reference for the crack detection of Lamb wave.

关 键 词：检测 激光超声 可视化 兰姆波 散射 

分 类 号：TB551[理学—物理]