【摘要】 针对现有缺陷检测方法难于快速判断接地极腐蚀程度，研究分析超声导波技术检测不同结构接地网的可行性。通过分析导波的传播机理，得低阶SH导波适合于接地极检测。采用有限元仿真软件建立3种不同杆塔结构三维接地网模型，分析导波的传播特性。考虑到接地极所处实际环境，研究了不同土壤电阻率下接收端信号的变化特征，其回波信号幅值会随土壤电阻率的升高而增大。此外，对接地扁钢中存在的缺陷及其表面形成的腐蚀层厚度变化进行了研究。结果表明，低阶SH导波能有效检测出接地极缺陷，腐蚀层厚度变化对回波信号幅值影响较小。更多还原

【Abstract】 In view of the difficulty of the existing defect detection methods to quickly judge the degree of grounding pole corrosion, the feasibility of ultrasonic guided wave technology to detect grounding grids with different structures was studied and analyzed. By analyzing the propagation mechanism of guided wave, it is found that low-order SH guided wave is suitable for ground pole detection. The finite element simulation software is used to establish three kinds of three-dimensional grounding network models of different tower structures and analyze the propagation characteristics of guided waves. Considering the actual environment of the grounding pole, the variation characteristics of the receiver signal under different soil resistivity are studied. The amplitude of the echo signal increases with the increase of soil resistivity. In addition, the defects existing in the flat steel and the thickness variation of the corrosion layer formed on its surface were studied. The results show that the low-order SH guided wave can effectively detect the ground pole defects, and the variation of corrosion layer thickness has little influence on the echo signal amplitude.更多还原