基于线性调频Lamb波的铝板裂纹成像融合技术

Aluminum Plate Crack Imaging Fusion Technology Based on Chirp Lamb Wave

中文关键词:  线性调频信号  成像融合  矢量全聚焦成像  裂纹检测

英文关键词:chirp signal  imaging fusion  vector full-focusing imaging  crack detection

中文摘要:

      全聚焦成像为铝板提供了一种结构损伤可视化的方法，在无损检测中显示出巨大的潜力。融合多种频率下的全聚焦成像图能够提高成像质量。为了获取多频数据，需要进行多次重复实验，为了降低实验成本、提高效率，采用线性调频激励能够一次获取包含多种频率信息的数据。通过线性调频激励，得到幅值全聚焦成像和矢量全聚焦成像，并将多频成像结果进行融合，利用融合后的成像结果和矢量全聚焦得到的裂纹角度对铝板裂纹的扩展进行定量测量，并对比统计全部数据作为样本和仅统计裂纹方向数据作为样本2种方法对裂纹扩展的定量测量准确性，以及不同频率成像和融合成像对裂纹扩展的定量测量准确性，得出融合成像和选取裂纹方向上的数据能够更有效地提高裂纹长度检测的准确性。

英文摘要:

      Full-focusing imaging provides a visualized approach for structural damage inspection in aluminum plates and demonstrates significant potential in non-destructive test.Fusion of full-focusing imaging maps at multiple frequencies can enhance imaging quality.To obtain mulitifrequency data,multiple repeated experiments are required.In order to reduce the experimental cost and improve the efficiency,the chirp excitation can obtain the data containing multiple frequency information at once.Though the chirp excitation,the amplitude full-focusing imaging and vector full-focusing imaging are obtained and the fusion of multi-frequency imaging results are fused.The extension of the aluminum plate crack is quantitatively measured using the fused imaging results and the crack angle obtained by vector full-focusing.The quantitative measurement accuracy of crack extension using all data and only crack orientation data as samples and the quantitative measurement accuracy of crack extension using different frequency imaging and fused imaging are compared.The fused imaging and selecting crack orientation data are more effective in enhancing the accuracy of crack length detection.