就一简化的三维磁性材料数值计算模型，对其非线性涡流信号进行了数值模拟试验。基于变形磁矢量位(Ar)低频涡流场的控制方程改良并开发了用于计算非线性涡流检测信号的数值模拟程序，得出非线性涡流检测信号与磁性材料因塑性变形而产生的磁导率变化之间的相关性，开发了非线性涡流信号数值模拟程序，利用开发的数值模拟程序计算非线性涡流检测信号，采用不同初始磁导率等效模拟试件不同塑性变形程度，得出了模拟信号的谐波幅值与塑性变形的关联性。对比非线性涡流数值模拟结果和试验检测结果，证明了塑性变形导致的磁导率变化是非线性涡流检测信号变化的直接诱因。

For a simplified three-dimensional numerical model of magnetic materials, numerical simulation research of nonlinear eddy current detection signal of the modal was carried out. A simulation method and numerical code which was used to calculate nonlinear eddy current detection signal was developed based on reduced vector potential(Ar) formulation. Furthermore, relationship between nonlinear eddy current detection signal and permeability variation which was caused by plastic deformation of magnetic materials was obtained. Numerical code of nonlinear eddy current detection signal was developed. Nonlinear eddy current detection signal was calculated by numerical simulation program. Relationship between harmonic amplitude of analog signal and plastic deformation was obtained by using different initial permeability equivalent to different deformation. Comparing results of numerical simulation with experimental results, it is proved that permeability variation which was caused by plastic deformation was the direct incentive of nonlinear eddy current detection signals change.