A Model-Based Method for Eddy Current Testing of Conductive Structure Thickness and Conductivity

Abstract

The invention discloses a conductive structure thickness and conductivity eddy current testing method based on a model; the method comprises the following steps: 1, design beginning; 2, building a measuring model; 3, frequency optimization; 4, model correction; 5, initializing parameters and optimizing algorithm; 6, calculating deviation between a simulation value and an experiment value; 7, determining whether termination conditions are met or not; 8, outputting the conductivity and thickness; 9, ending the design. The method can simultaneously detect the thickness and the conductivity, and can introduce the correction parameter so as to weaken the influences on the result by coil stray capacitance, thus improving the detection precision.

Description

technical field [0001] The invention relates to a model-based eddy current testing method for the thickness and conductivity of a conductive structure, belonging to the field of nondestructive testing. Background technique [0002] Metal sheets, films and conductive coatings and coatings are widely used in automobiles, aircrafts, machinery and equipment and other fields. Thermal barrier coatings have been widely used in the production of hot-end components such as turbine blades of engines. The manufacturing process will change the performance of thermal barrier coatings, and aging will affect the quality and life of coatings. In order to ensure product quality and maintain in-service performance, necessary testing must be done on thermal barrier coatings, and thickness and electrical conductivity are two key parameters concerned during the testing process. [0003] So far, the detection methods available for thickness and conductivity include ultrasonic, microwave, four-pr...

AI Technical Summary

Problems solved by technology

Ultrasonic method can be used for thickness detection, but it needs coupling agent; four-probe method can be used for conductivity detection, but it needs pretreatment of the surface, and the operation is relatively complicated, so it is difficult to realize online detection; microwave method is expensive

[0004] Non-model-based eddy current testing requires repeated calibrations and usually only measures a single parameter, while model-based eddy current testing technology repeatedly adjusts the estimated values ​​of the parameters to be measured by comparing the deviation between model simulation and experimental measurement results until the model simulation The deviation from the experimental measurement results is the smallest, and multiple parameters can be measured at the same time, without repeated calibration. However, in practical applications, the model does not consider the influence of coil stray capacitance, and the effective value of impedance change is difficult to obtain, resulting in detection The result is less accurate

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