Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

MEASUREMENT OF CTOA OF PIPE STEELS USING MDCB AND DWTT SPECIMENS

Published

Author(s)

Christopher N. McCowan, S. Xu, W. R. Tyson, R. Eagleson, Elizabeth S. Drexler, J. D. McColskey, Philippe P. Darcis

Abstract

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 Title
Proceedings of the 8th International Pipeline Conference IPC2010
September 27-October 1, 2010, Calgary, Alberta, Canada
Conference Dates
September 27-October 1, 2010
Conference Location
Calgary

Keywords

CTOA, MDCB, DWTT, ductile fracture, fracture toughness, pipe steel, test method

Citation

McCowan, C. , Xu, S. , Tyson, W. , Eagleson, R. , Drexler, E. , McColskey, J. and Darcis, P. (2010), 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 March 29, 2024)
Created September 27, 2010, Updated February 19, 2017