多层导电结构厚度电涡流检测正向模型及仿真器研究

首先推导出有限截面圆柱形线圈置于多层导电结构上方时,各种参数与阻抗变化关系的数学模型;接着研究该正向模型的求解方法和计算技术,并建立了一个多层厚度电涡流检测仿真器,仿真计算了单层板、金属基体上导电涂层厚度以及多层导电结构板间间隙检测时待测厚度值变化导致的探头阻抗响应值,分析了变化规律,并进行了实验验证.仿真器的仿真结果可为实际检测系统参数设计提供理论依据,且可在基于模型的反演算法中提供正向解.

Forward Model and Simulator of Thickness Measurement of Multi-Layered Conductive Structures by Eddy Current Technique

The impedance change model of a probe coil above a structure with an arbitrary number of parallel layers is put forward. The solving method and calculation procedure of the forward model are investigated and then a simulator for the thickness measurement of multi-layered structures is established. The simulation results of thickness measurement of single layer, 3 layers and 4 layers are calculated using the simulator and the trends of the impedance and thickness change curves are analyzed. The merits of the forward model and simulator are proofed by the experimental results.