频率-波数域的薄铝板缺陷检测研究

文章将频率-波数域成像算法应用于薄铝板内圆形穿孔缺陷的检测。采用PZFlex软件建立多阵元线性阵列仿真模型,在薄铝板内激发出Lamb波,模拟超声相控阵全矩阵捕获功能。实验中使用M2M公司的超声相控阵仪器对带有通孔缺陷的薄铝板进行全矩阵捕获。基于全矩阵数据完成自发自收模式下的频率-波数法损伤重建,对全矩阵数据进行三维傅里叶变换,利用所有阵列的全部信息完成损伤重建。实验结果表明:频率-波数域成像法能够精确地表征出圆孔损伤的大小和形状,对单缺陷及不同大小、距离的双缺陷均具有良好的检测效果。相对于全聚焦成像法,频率-波数域成像法具有更高的分辨率。

Defect detection of thin aluminum plates in frequency-wavenumber domain

In this paper, the frequency-wavenumber (F-W) domain imaging algorithm is used to detect circular perforation defects in thin aluminum plate. A simulation model of multi-element linear array is established by PZFlex software, and the Lamb wave excited in a thin aluminum plate is used for simulating the full matrix capture function of ultrasonic phased array. In the experiment, the ultrasonic phased array instrument of M2M Company is used to capture the full matrix data of the thin aluminum plate with perforation defects. Based on the full matrix data, the F-W domain imaging method is used to reconstruct the defect damage in the self-transmitting and self-receiving mode. The 3D Fourier transform is performed on the full matrix data, and all the information of the array is used to complete the damage reconstruction. Experimental results show that the F-W domain imaging method can accurately characterize the size and shape of the circular damage, and has a good detection effect for a single defect and double defects of different sizes and distances. Compared with the total focusing method (TFM), the F-W domain imaging method has higher resolution.