The metal plate structure is more and more widely used in many fields, such as aerospace, high-speed railway, civil engineering, etc. In the process of long-term service, this structure is susceptible to cracks, spalling, fatigue, and other damages caused by external load impact, chemical corrosion, and other effects. A significant challenge is to find and determine the location of small damage. Aiming to address this problem, the frequency-wavenumber (f-k) domain filtering method is adopted. According to the corresponding relationship between the propagation direction of the guided wave and the frequency wavenumber matrix and combined with the characteristics of the difference in wavenumber of different modes of guided waves at the same frequency, a three-dimensional window function is constructed to realize the extraction of different modes and their corresponding damage reflection signals. The Common Source Method (CSM) time domain and f-k domain imaging methods have been used to achieve damage imaging. Finally, the data fusion imaging method has been used to weight the damage imaging results of different modes to further improve the accuracy of damage imaging.

金属板结构在航空航天、高铁、土木工程等领域的应用越来越广泛，在长期服役的过程中，这种结构容易出现裂纹、剥落、疲劳等问题。由外部负载冲击、化学腐蚀和其他影响引起的损坏。一个重大的挑战是找到并确定小损伤的位置。为了解决这个问题，频率波数 ( f - k) 采用域过滤方法。根据导波传播方向与频率波数矩阵的对应关系，结合同一频率下导波不同模式波数差异的特点，构造三维窗函数，实现提取不同模式及其相应的损伤反射信号。共源方法 (CSM) 时域和f - k域成像方法已被用于实现损伤成像。最后，利用数据融合成像方法对不同模式的损伤成像结果进行加权，进一步提高损伤成像的精度。