Abstract

The present work is an experimental study of Lamb waves propagation in an aluminum plate with an impact damage in the size of the S0 mode wavelength. The aim of this study is to visualize the wavefield near the defect in the case of extreme diffusion, as well as the interference of the modes inside of it and their transformation. The results were obtained by applying the continuous wavelet transform (CWT) on the wavefield data recorded by two ultrasonic scanning techniques: the air coupled ultrasonic (ACU) and the Laser doppler vibrometry (LDV), to obtain a C-scan and a B-scan of the plate respectively. Space-wavenumber representations showed the behavior of Lamb waves in the plate as well as the reduction in thickness of the impacted area. The width of the latter could be estimated and the modes present at each position of the plate could be identified.

中文翻译：

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Lamb波在冲击波内部传播所用波长大小的实验研究

摘要

目前的工作是对兰姆波在铝板上传播的实验研究，该冲击对S0模式波长的大小造成了影响。这项研究的目的是在极端扩散的情况下可视化缺陷附近的波场，以及缺陷内部的模态及其转换。通过对通过两种超声扫描技术记录的波场数据应用连续小波变换（CWT）来获得结果：空气耦合超声（ACU）和激光多普勒振动计（LDV），以获得C扫描和B-分别扫描板。空间波数表示法显示了板中的兰姆波的行为以及受影响区域厚度的减小。