08. SF-X-CRK.EXE on JSAEM Problem 6a

SF-X-CRK.EXE significantly underestimates the magnitude of the ET signal, although there is a "ball park" agreement between the calculation and experimental data. An important contributing factor on this result is that SF-X-CRK.EXE assumes the planar flaws are infinitesimally thin. The notches used in the JSAEM Problem #6 test had large widths (0.22 mm) and could be considered to have significant volumetric aspects. For these notches, the width to depth ratio was relatively large. Thinner notches would have been better representations of real cracks than those that were used for this experimental data.

Effects of notch widths on ET signals are being studied. Preliminary results from one study has been documented here:

http://www.cnde.iastate.edu/mapod/2009%20October/Review%20of%20Ongoing%20U.S.%20Efforts%20%28Thompson%20for%20Nakagawa%29.pdf