摘要
裂纹是涡流检测中最常遇到的缺陷类型。由于它的开口宽度很小 ,用有限元法计算其涡流场困难很大。利用理想裂纹的模型 ,忽略缺陷宽度 ,用二维的面缺陷近似三维的体缺陷 ,使用积分方程法计算裂纹缺陷涡流场问题 ,可大大减少计算量。问题可以分解为求导体内不含缺陷的完好场和求缺陷等效源产生的扰动场两部分 ,本文就半无限导体系统分别研究这两部分的求解。线圈阻抗的计算值与实验结果进行了比较 。
A thin opening crack in conductor is one of the most important types of defects in eddy current nondestructive testing. It is difficult to calculate the eddy current field of this kind of system using finite element method because much fine meshes are required due to the thin opening of the crack. By utilizing the ideal crack model which ignores the crack width and takes the 3D volumetric crack as a 2D areal defect, the eddy current field can be calculated by solving an integral equation. The problem has been divided into two parts. One is the solution of “perfect field” with absence of crack in the conductor and the other is the solution of “disturbed field” due to the crack equivalent source. Both of the two parts have been investigated for a half infinite conductor system. The probe impedance change due to the crack has been evaluated. The numerical predictions have been compared with experiments and good agreement has been found.
出处
《无损检测》
2000年第3期99-105,共7页
Nondestructive Testing
