激励电流对脉冲涡流检测的影响研究

在采用脉冲涡流技术进行缺陷检测时,不同激励线圈中的电流会存在一定的差异。为研究不同线圈内激励电流对检测结果的影响,首先分析了不同线圈内激励电流的时频特征,然后研究了被测试件缺陷尺寸和材料属性不同时,不同激励电流作用下差分检测信号的频谱特征,分析了激励电流对检测信号频谱特征的影响规律。最后通过实验对分析结果进行了验证,结果表明:当被测试件缺陷尺寸不同时差分检测信号频谱特征受激励信号影响的规律也不同。

Study on the effect of excitation current on pulsed eddy current testing

When pulsed eddy current technique is used in defect testing, the currents in different exciting coils have certain difference. In order to study the effect of the excitation currents in different coils on pulsed eddy current testing result, the time-frequency feature of the currents in different exciting coils is analyzed firstly, then the frequency spectrum characteristics of the differential testing signals under different excitation currents for different defect sizes and material characteristic of the tested parts are studied, and the influence law of the excitation current on the frequency spectrum of the testing signal is analyzed. Finally, experiment was performed to verify the analysis results, and the results indicate that when the defect size of the tested specimen is different, the effect law of the excitation current on the frequency spectrum of the differential testing signal is also different.