The boundary element method (BEM) is an efficient way to compute solutions of eddy current nondestructive evaluation (NDE) problems. However, in boundary element analysis of eddy currents, the computational accuracy and efficiency depend on the element discretization employed and are very sensitive to the liftoff distance and the relative geometry size between the detecting coil and object under evaluation or test. In this paper, the skin depth parameter is applied to study the element discretization effects on boundary element analysis for 3D eddy current NDE problems. The element discretization rules are concluded by conducting numerical experiments for different liftoff distances and relative probe sizes so that they can be adjusted to account for variations in these parameters, and validated against the analytical method, semi-analytical method, and experiments of some benchmark problems. With the help of the rules, the overall computational accuracy is improved while the cost is reduced for the BEM modeling of eddy current NDE problems.

边界元法 (BEM) 是计算涡流无损评估 (NDE) 问题解的有效方法。然而，在涡流的边界元分析中，计算精度和效率取决于所采用的元离散化，并且对提升距离和检测线圈与被评估或测试对象之间的相对几何尺寸非常敏感。在本文中，趋肤深度参数被用于研究元素离散化对 3D 涡流 NDE 问题边界元分析的影响。单元离散化规则是通过对不同的升空距离和相对探针尺寸进行数值实验得出的，以便可以调整它们以考虑这些参数的变化，并针对分析方法进行验证，半解析方法，以及一些基准问题的实验。借助规则，提高了整体计算精度，同时降低了涡流无损检测问题的边界元建模成本。