管材涡流探伤最佳频率数值模拟与试验验证

目前广泛采用的确定涡流探伤频率的方法主要是特征频率法和试验法，两种方法得出的频率通常不是最佳频率。采用ANSYS数值计算方法对人工标准缺陷的信号进行数值模拟，从而找出对内外壁缺陷信号的幅度都比较大，并且内外壁缺陷信号的相位差接近极大的激励频率。经过试验验证，计算结果与试验结果完全符合。结论认为，用ANSYS信号模拟方法可以找出最佳的激励频率，既能兼顾内外壁缺陷的检测灵敏度，又能从相位上区分内外壁缺陷的激励频率。

Study on Optimum Frequency for Eddy Current Testing of Tubes by Numerical Modeling and Experimental Verification

The characteristic frequency and experimental methods are widely used at present for selection of exciting frequencies with which eddy current NDT of tubes are conducted. The methods are not accurate enough for finding the optimum frequency. The frequencies selected by the methods are always a little far from the optimum. A new method based on numerical modeling of flaw signals with ANSYS was developed. In this way the optimum exciting frequency was found. The optimum means that both the signals from ID and OD artificial defects were higher and the difference between the phases of the two signals reached nearly the maximum. The experiments of eddy current NDT on tubes with the ID and OD artificial defects were conducted. The results of the experiments agreeed with those of numerical modeling very well. It Was concluded that the new method was accurate enough for finding the optimum exciting frequency.