中文摘要：

针对已有脉冲涡流集总参数模型的不足,建立了具有一般性的脉冲涡流集总参数模型.首先将导体试件中的脉冲涡流场等效为一簇沿深度方向排开的同轴等半径的涡流环;然后建立了涡流随时间和空间分布的偏微分矩阵方程,推导了涡流回线的电阻、自感与互感计算公式;接着阐述了系统矩阵的特征值和特征向量的物理意义;最后使用有限差分法求解了模型实例的矩阵方程,并进行了实验验证.该模型推导、求解简单,适用于任意厚度的被测试件,能准确地模拟瞬态涡流场的扩散过程,也能预知试件厚度变化时线圈感应电压的变化情况.

英文摘要：

In order to improve lumped-parameter models（LPM） for pulsed eddy current testing（PECT）,a more general LPM was presented.First,tra nsient eddy-currents in the specimen were equivalent to a series of concent ric vortex ring arrayed along the depth direction and of the same radius.Then,the partial differential matrix equation governing the temporal and spatial distribu tion of eddy currents were established.The expressions for the resistance,self inductance and mutual inductance of eddy current filaments were derived.After that,the eigenvalues and eigenvectors of the system matrix were calculated and their physical interpretations were described.Finally,finite difference method was used to calculate the matrix equation of a simple LPM instance.Experimenta l verification was also performed.The presented model is easy to derive and cal culate and suitable to the specimens of arbitrary thickness,which can be used f or simulating the transient eddy-currents diffusion process and predicting the coil-induced voltage variation when the specimen thickness changes.