Single-edge notched tension (SE(T) or SENT) specimens have been increasingly proposed as a low-constraint toughness test to measure toughness of line pipe materials, as the crack tip constraint approximates a circumferential surface flaw in a pipe under loading. The clamped SE(T) single-specimen procedures recently developed by Shen and Tyson (2008, “Fracture Toughness Evaluation of High Strength Steel Pipe,” ASME Paper No. PVP2008-61100; 2008, “Development of Procedure for Low-Constraint Toughness Testing Using a Single-Specimen Technique,” CANMET Materials Technology Laboratory, Technical Report No. 2008-18 (TR)) and Tang et al. (2010, “Development of the SENT Test of Strain-Based Design of Welded Pipelines,” 8th International Pipeline Conference, IPC 2010, Calgary, AB, Canada) have both used in common the use of a clamped single-specimen of similar geometry and relied on the unloading compliance technique for crack size estimation. In the former case, a single clip gauge is attached to the integral knife edge and the crack-tip opening displacement (CTOD) is estimated by means of a J-integral-to-CTOD conversion, similar to the procedure of ASTM E1820-11. The latter uses a pair of clip gauges mounted on an attachable raised set of knife edges to estimate CTOD at the original crack tip position by a triangulation rule. Consolidating these two sets of clip gauges in a specimen makes direct comparisons of two SE(T) methods under identical test conditions: material, specimen geometry, equipment, test temperature, and operator (Weeks et al., 2013, “Fracture Toughness Instrumentation Techniques for Single-Specimen Clamped SE(T) Tests on X100 Linepipe Steel: Experimental Setup,” 6th Pipeline Technology Conference, Ostend, Belgium). In this study, SE(T) testing employing these two SE(T) methods on a single specimen was conducted on B × B shallow-cracked (a/W ∼ 0.35) specimens of two X70 pipeline girth welds. This paper discusses details of the two SE(T) methods and techniques on the same specimen.

References

References
1.
Moore
,
P.
,
Pisarski
,
H.
, and
London
,
T.
,
2013
, “
Validation of Methods to Determine CTOD From SENT Specimens
,” TWI,
Technical Report No. 1034/2013
.
2.
Shen
,
G.
,
Gianetto
,
J. A.
, and
Tyson
,
W. R.
,
2008
, “
Development of Procedure for Low-Constraint Toughness Testing Using a Single-Specimen Technique
,” CANMET Materials Technology Laboratory, Technical Report No. 2008-18 (TR).
3.
ASTM
,
2011
, “
Standard Test Method for Measurement of Fracture Toughness
,”
ASTM International
,
West Conshohocken, PA
, ASTM E1820-11.
4.
Shen
,
G.
,
Bouchard
,
R.
,
Gianetto
,
J. A.
, and
Tyson
,
W. R.
,
2008
, “
Fracture Toughness Evaluation of High Strength Steel Pipe
,”
ASME
Paper No. PVP2008-61100.
5.
Norske Veritas, 2006, “DNV Recommended Practice ‘Fracture Control for Pipe-line Installation Methods Introducing Cyclic Plastic Strain’,” Norske Veritas, Oslo, Norway, DNV-RP-F108.
6.
Tang
,
H.
,
Macia
,
M.
,
Minnaar
,
K.
,
Gioielli
,
P.
,
Kibey
,
S.
, and
Fairchild
,
D.
,
2010
, “
Development of the SENT Test of Strain-Based Design of Welded Pipelines
,”
ASME
Paper No. IPC2010-31590.
7.
Norske Veritas, 2000, “
DNV Offshore Standard ‘Submarine Pipeline Systems’
,” Norske Veritas, Oslo, Norway, DNV-RP-F101, 2000.
8.
Weeks
,
T. S.
,
McColskey
,
J. D.
,
Read
,
D. T.
, and
Richards
,
M. D.
,
2013
, “
Fracture Toughness Instrumentation Techniques for Single-Specimen Clamped SE(T) Tests on X100 Linepipe Steel: Experimental Setup
,”
6th Pipeline Technology Conference
,
Ostend, Belgium
.
9.
Fonzo
,
A.
,
Melis
,
G.
,
Di Vito
,
L.
,
Mannucci
,
G.
,
Darcis
,
P.
,
Richard
,
G.
,
Quintanilla
,
H.
, and
Armengol
,
M.
,
2009
, “
Techniques for Fracture Toughness Testing of Offshore Pipelines
,”
ASME
Paper No. OMAE2009-80135.
10.
Tyson
,
W. R.
, and
Fonzo
,
A.
,
2013
, personal communication.
11.
Shen
,
G.
, and
Tyson
,
W. R.
,
2009
, “
Crack Size Evaluation Using Unloading Compliance in Single-Specimen Single-Edge-Notched Tension Fracture Toughness Testing
,”
J. Test. Eval.
,
37
(4), pp.
347
357
.
12.
Cravero
,
S.
, and
Ruggieri
,
C.
,
2006
, “
Evaluation of Crack Growth Resistance Curves for Pipeline Steels Using Constraint Designed Fracture Specimens
,”
ASME
Paper No. IPC2006-10075.
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