Characterization of deep-lying fatigue cracking arising in eddy current testing

This paper is concerned with deep-lying effects in fatigue cracking from eddy current testing (ECT) signals. The fatigue crack often remains tightly closed, and thus difficult to find by visual inspection. It is important to estimate the direction of crack growth because of evaluating the common mode of failure in structural and mechanical engineering components. Our study is aimed at developing a practical method for identifying deep-lying profiles from surface image obtained by scanning ECT probe. A various type of fatigue cracks are made from compact tension (CT) specimen of aluminum alloy samples. ECT signals are collected for those test samples using transmit-receive (TR) probe. We discuss the features of ECT profiles of fatigue cracking which are different from electric discharge machining (EDM) crack signals.