利用有限元法分析涡流远场效应的能流通道

涡流远场检测的激励线圈和检测线圈相距较远,两线圈信号相位差对管内壁缺损和管外壁缺损具有相同的灵敏度。传统的涡流理论难以解释涡流远场现象。为了解释涡流远场现象,T.R.Schmidt提出了“能量通道说”,假设检测线圈中的信号是由从激励线圈附近向外穿过管壁再从检测线圈附近向内穿过管壁后的能量激发产生的。本文利用有限元法分析了铁磁性钢管内能量的可能传递途径,结果表明“能量通道说”中的假设是正确的。

Finite Element Analysis on Energy Flow Path of the Remote Field Eddy Current Effect

In a single tube, a remote field eddy current detector separated axially from the exciter by a few pipe diameters offers equal sensitivity to internal and external defects. It is difficult to explain the remote field eddy current effect by the conventional eddy current theory. There is a hypothesis called "the energy flow path" that the energy received by the detector at a point inside the tube in the remote field travels through the wall from the exciter to the exterior of the pipe and then back to the interior of the pipe. This paper analyses the probable energy flow paths in the steel pipe and verifies the hypothesis of "the energy flow path" .