An automatic flaw classification method for ultrasonic phased array inspection of pipeline girth welds

摘要

In this paper, a novel method for automatic flaw classification in ultrasonic phased array NDT applied to pipeline girth welds has been developed using the LWT, fractal analysis, the GA algorithm and a SVM. The fractal dimensions of the flaw signals were found to be closely related to the type of flaw. It was easy to identify THs and RHs, but some NHs and FHs were difficult to recognise. Experimental results showed that the proposed method is robust and suits the requirements of UPA online automatic flaw classification. Based on this method, a fast and user-friendly classification system has been developed, which can assist inspection technicians in quantitative and qualitative analysis of the UPA NDT.