ISSN: 1945-7553
CODEN: JTEVAB
Page Count: 5

Comparison of Finite Element Results and Experimental Measurements of CTOD δ₅ in CT Specimens

Nikishkov, GP
Institute of Materials Research, GKSS Research Center, Geesthacht,

Heerens, J
Institute of Materials Research, GKSS Research Center, Geesthacht,

Hellmann, D
Institute of Materials Research, GKSS Research Center, Geesthacht,

(Received 16 September 1998; accepted 15 June 1999)

Abstract

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.

Keywords:
CTOD, curved crack front, compact tension specimen, finite element method

Paper ID: JTE12230J
DOI: 10.1520/JTE12230J
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