采用时频分析方法，研究导波在金属管道中频散特征与缺陷尺寸间的映射关系。基于有限元分析软件ANSYS，采用单元生死法建立9组不同周向尺寸和径向深度缺陷的管道模型，用脉冲−回波的方法模拟L(0,2)模态波对管道的激励；基于Gabor变换和导波频散特性，提取缺陷回波时间、反射系数等特征参数。研究结果表明：管道裂纹缺陷的轴向定位误差为1.48%；缺陷处的反射系数较大，且反射系数随着损伤程度的变大而增大。%The mapping relationship between the frequency dispersion characteristics and the defect size of the guided wave in the metal pipe medium was studied with joint time-frequency analysis method. Firstly, numerical simulation were performed with the finite element analysis software ANSYS, modeling nine kinds of defective pipeline models in circumferential size and radial depth were established with element birth and death method, and excitation of L(0,2) mode wave to pipe was simulated with pulse-echo. Then, features such as time of echo signal and reflection coefficient were extracted with Gabor transform and dispersion characteristics of guided wave. The results show that the axial positioning accuracy of pipeline crack defects reaches 1.48%, and the reflection coefficient is larger in the defects and decreases as the damage degree increases.
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