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Lamb波损伤成像是结构健康监测的研究热点之一,然而在实际应用中,成像分辨率很容易受到Lamb波频散特性的影响。本文研究了非频散信号构建(ND-SC)的频散补偿方法并用于提高Lamb波成像分辨率。根据频域中建立的Lamb波传感模型,分析了ND-SC原理,并分别按照宽带激励和窄带激励两种情况对ND-SC的实现方式进行了讨论。随后结合经典的延迟叠加算法提出了高分辨率损伤成像方法。针对铝板的实验结果证明了本文提出的ND-SC方法和高分辨率损伤成像方法的有效性。
Lamb wave damage imaging is one of the hot topics in structural health monitoring. However, in practical applications, imaging resolution is easily affected by the dispersion characteristics of Lamb waves. In this paper, the dispersion compensation method of non-dispersive signal construction (ND-SC) is studied and used to improve the resolution of Lamb wave imaging. According to the Lamb wave sensing model established in the frequency domain, the principle of ND-SC is analyzed and the implementation of ND-SC is discussed according to the two cases of wideband excitation and narrowband excitation respectively. Then combined with the classic delay stacking algorithm proposed high-resolution damage imaging method. Experimental results on aluminum plate demonstrate the effectiveness of the proposed ND-SC method and high-resolution damage imaging method.