Gp. Nikishkov et al., Comparison of finite element results and experimental measurements of CTODdelta(5) in CT specimens, J TEST EVAL, 27(5), 1999, pp. 307-311
Elastic-plastic finite element modeling of the CTOD delta(5) measuring proc
edure is performed for CT specimens made from 22NiMoCr37 containing fatigue
precracks with curved crack fronts. It is shown that a discrete model with
curved crack front and actual position of the clip gage provides reasonabl
e accuracy of results. An approximate model with straight crack front of av
erage crack depth and actual location of the clip gage can also be used. It
is proposed to adjust experimental delta(5) values for the deviation of ac
tual crack front curvature alpha from a specific value. The use of the adju
stment procedure decreases the scatter of experimental values of CTOD delta
(5) considerably.