横截面为任意形状的表面开口缺陷的漏磁场

Magnetic Leakage Field Yielded by A Surface Breaking Discontinuity with Any Shape Transversal Section

由磁荷分水岭概念分析了任意形状横截面表面开口缺陷所产生的漏磁场H,推得H∝(d-2kδ-2E),其中d是缺陷的最大深度,k是比例系数,δ是缺陷横截面上磁荷分水岭沿缺陷深度方向的微小偏移,而E是取决于磁荷分水岭的常数。从而可得出下列结论,①只有d和E很小时,或d W(W为缺陷长度)时,才近似有H∝d的关系。②当d W时,可粗略估计H与d无关,而只取决于W。③无法从缺陷漏磁场的量值和分布反演出表面开口缺陷横截面的形状。

The magnetic leakage field H yielded by a surface breaking discontinuity with any shape transversal section is analyzed from the concept of the watershed of magnetic charges. It is deduced that H∝： （d-2kδ-2E）, in which d is the maximum depth of the defect, k is a coefficient, 8 is a small deflexion of the watershed of magnetic charges on the transversal section along the direction of the flaw depth, E is a constant depending on the watershed of magnetic charges. Thereby the following conclusions may be reached, ① Only when d, E are very small or when d（〈W （the length of the discontinuity）, there will be the relation, that Hoed. ② When d〉〉W, in a rough estimation H is independent of d, and only depending on W. ③ The figure of the transversal section of a surface breaking discontinuity can not be calculated out conversely from the magnitude and the distribution of its magnetic leakage field.