Eddy Current and Thermal Propagation for Quantitative NDT&E

As excitation factors of heating time and power directly affect the behaviour of eddy current and thermal propagation for eddy current pulsed thermography (ECPT), it is necessary to investigate the optimal parameters to maximize contrast between the defective and non-defective area as well as quantitative evaluation. The defect evaluation on complex geometry in the structural especially edges remains challenge due to multi-parameters effect. Suitable excitation factors are requested to edge structure detection for reducing the effects by complex geometry and improving the maximize contrast between the defective and non-defective. This paper researches the optimize excitation parameters strategy and demonstrate the positive effect for defect detection under these parameters. Under the premise of the uniform electromagnetic and thermal fields, the relationships between the excitation parameters and the physical mechanism are established by the separation of Joule heat via eddy current and thermal diffusion. The impact of the various parameters of excitation power and heating duration for edge detection is investigated. Appropriate stimulation current and heating period for promotion the detectability such as thermal contrast and SNR are reported, which will benefit to the quantitative evaluation of the defect detection.