Volume 27, Issue 5 (September 1999)
Comparison of Finite Element Results and Experimental Measurements of CTOD δ5 in CT Specimens
Elastic-plastic finite element modeling of the CTOD δ5 measuring procedure 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 reasonable accuracy of results. An approximate model with straight crack front of average crack depth and actual location of the clip gage can also be used. It is proposed to adjust experimental δ5 values for the deviation of actual crack front curvature a from a specific value. The use of the adjustment procedure decreases the scatter of experimental values of CTOD δ5 considerably.