跑道型差动式涡流探头设计及其性能研究

针对传统差动式涡流探头几何尺寸大、缺陷检测灵敏度低的问题，在传统差动式涡流探头的基础上，设计了一种跑道型差动式涡流探头。它由激励线圈包裹2个尺寸相同、反向连接的感应线圈而构成。首先，利用COMSOL Multiphysics仿真软件建立了跑道型差动式涡流探头模型，比较了跑道型差动式涡流探头与传统差动式涡流探头涡流场分布的差异，并研究了在不同缺陷深度、不同扫查角度下2种差动式涡流探头的检测灵敏度。接着，制作了跑道型差动式涡流探头实物和碳钢板缺陷试件，利用试验测试的方法比较了跑道型和传统差动式涡流探头的检测灵敏度。试验结果表明，与传统差动式涡流探头相比，跑道型差动式涡流探头具有更紧凑的结构、更高的缺陷检测灵敏度。研究结果可为小尺寸、高精度差动式涡流探头的优化设计提供参考。

Design and performance study of runway-type differential eddy-current probe

Aiming at the problem of large geometry size and low sensitivity of defect detection of the traditional differential eddy-current probe, a runway-type differential eddy-current probe was designed on the basis of the traditional differential eddy current probe, which was composed of two induction coils with the same size and reverse connection wrapped by a runway-type excitation coil. Firstly, the COMSOL Multiphysics simulation software was used to establish a runway-type differential eddy-current probe model, and the difference of eddy-current field distribution between the runway-type differential eddy-current probe and the traditional differential eddy-current probe was compared. The detection sensitivity of two kinds of differential eddy-current probes under different defect depths and scanning angles was studied.Next, a runway-type differential eddy-current probe and a carbon-steel plate defect specimens were made, and the detection sensitivities of the runway-type and traditional differential eddy-current probes were compared by experimental testing. The test result showed that the runway-type differential eddy-current probe had a more compact structure and higher defect detection sensitivity compared with the traditional differential eddy-current probe. The research result can provide reference for the optimization design of small size and high precision differential eddy-current probe.