Manager, Edison Welding Institute, Columbus, OH
Head, U.K. Admiralty Research Establishment, Holton Heath, Poole
Pages: 21 Published: Jan 1991
This paper presents the results of an experimental program to study size and geometry effects in CTOD R-curves. The results were obtained from room temperature unloading compliance R-curve tests on different sized single-edge-notch bend (SENB) specimens made from HY100 steel. The crack growth resistance was measured in terms of conventional CTOD, δo, (that is, as defined in BS 5762), CTOD corrected for crack growth, δR, and CTOD derived using a double clip gage arrangement δdc. It was found that all the CTOD R-curves exhibited upswings after crack extensions corresponding to approximately 17% of the initial uncracked ligament. Moreover, the slope of the CTOD R-curve increased dramatically after crack extensions corresponding to approximately 45% of the initial ligament. Apart from the R-curves obtained from the smaller specimens, normalizing the crack growth axis by dividing the crack extension by the initial ligament resulted in normalized CTOD R-curves which were in reasonable agreement over the entire crack growth range studied (that is, 60% of the initial uncracked ligament).
fracture mechanics, fracture toughness, ductile fracture, CTOD, R, -curves, J, -controlled crack growth, HY 100 steel, normalized , R, -curves
Paper ID: STP16848S