MEASUREMENT OF CTOA OF PIPE STEELS USING MDCB AND DWTT SPECIMENS
Christopher N. McCowan, S. Xu, W. R. Tyson, R. Eagleson, Elizabeth S. Drexler, J. D. McColskey, Philippe P. Darcis
Two types of specimen for crack tip opening angle (CTOA)measurement have been investigated for pipeline applications,i.e., the modified double cantilever beam (MDCB) (at NIST)and the drop-weight tear test (DWTT) specimen (at CANMET). Results of effects of specimen types, thicknesses and loading rates on CTOA are summarized and discussed. The main observations include: (i) For both MDCB and DWTT specimens tested at quasi-static loading rate, crack front tunnelling(i.e., with a deep triangular crack-tip shape) was present in high-strength steels; (ii) For DWTT specimens, CTOA values measured optically at the surface were signifi cantly higher than those from the simplifi ed single-specimen method (S-SSM)and measured at mid-thickness [on sections cut using electric discharge machining (EDM)]; and (iii) CTOA values from surface measurement of MDCB specimens were comparable to those derived from S-SSM of DWTT specimens, but the surface values of DWTT were higher than those of MDCB specimens.
Proceedings of the 8th International Pipeline Conference IPC2010
September 27-October 1, 2010, Calgary, Alberta, Canada
, Xu, S.
, Tyson, W.
, Eagleson, R.
, Drexler, E.
, McColskey, J.
and Darcis, P.
MEASUREMENT OF CTOA OF PIPE STEELS USING MDCB AND DWTT SPECIMENS, Proceedings of the 8th International Pipeline Conference IPC2010
September 27-October 1, 2010, Calgary, Alberta, Canada, Calgary, -1, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=905067
(Accessed December 9, 2023)