Applicability of simulation-assisted probability of detection analysis considering multiple signal features to eddy current testing of weld

Abstract

In this study, a simulation-assisted probability of detection (POD) analysis that considers multiple flaw parameters and signal features is presented, including an evaluation of its applicability to eddy current testing for weld inspection. In the proposed method, both the real and imaginary parts of eddy current signals were considered, unlike conventional methods that only consider signal amplitude. Type 304 stainless steel plates were joined by butt welding, and slits were fabricated on the weld path. The eddy current inspection was conducted using a uniform eddy current probe. Numerical simulations were also performed using the finite element method, with the model imitating the experimental situation. The POD contours were calculated using the proposed method, and they exhibited a reasonable tendency. In addition, the 95% lower confidence intervals of the proposed and conventional PODs were compared and were almost equal with respect to the decision threshold, indicating the applicability of the proposed method.