抄録
The quantitative evaluation of the surface fatigue crack size initiated from an artificial surface defect has been attempted using a DC potential drop (DCPD) technique for an aluminum alloy. A 5052–H34 aluminum alloy sheet with a small blind hole as a surface artificial defect has been used. Potential drop defined as a function of crack area and the correction factor α obtained from experimental data have been used in order to estimate crack depths. The estimated crack depth was slightly smaller than the actual crack depth. The measurement accuracy will be improved by increasing the sensitivity of potential measurement. The surface crack initiated from the artificial surface defect propagated with an almost constant aspect ratio a/c (a: crack depth, c : half crack length) after the crack reached the bottom of the artificial defect under the condition employed in this study.
