Volume 22, Issue 2 (March 1994)
Back-Face Strain Compliance and Electrical-Potential Crack Length Calibrations for the Disk-Shaped Compact-Tension DC(T) Specimen
Back-face strain compliance and electrical-potential crack length calibrations have been experimentally determined for the disk-shaped compact-tension DC(T) specimen. Finite-element modeling was used to ascertain the back-face strain distribution at several crack lengths to determine the significance of inconsistent gage placement. The numerical solutions demonstrated good agreement with experiment, especially at smaller crack lengths when the back-face strain gradients are minimal. It is concluded that precise gage placement is only critical when the crack tip closely approaches the back of the test specimen.