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Constraint-dependent CTOA determination for stable ductile crack growth

Journal Article · · Engineering Fracture Mechanics
 [1];  [2];  [3]
  1. Savannah River National Laboratory (SRNL), Aiken, SC (United States)
  2. Independent Consultant, Martinez, GA (United States)
  3. Univ. of South Carolina, Columbia, SC (United States)

The crack tip opening angle (CTOA) has been used as a reliable fracture toughness to characterize stable crack growth for thin-wall structures in low-constraint conditions. Recently, it is found that CTOA can also be utilized as a robust fracture parameter to describe the arrest fracture toughness for gas transmission pipelines in ductile steels. For better understanding the concept of CTOA, this paper presents a brief review on the CTOA definitions and its test methods. And then, four CTOA models are developed for determining the CTOA toughness using conventional single edge notched bend (SENB) specimens, including the load–displacement linear fit model, the logarithmic load–displacement linear fit model, the stable tearing energy model, and the J-differentiation model. Here fracture test data from SENB specimens in A285 carbon steel are employed to evaluate the proposed CTOA models. The results show that these CTOA models can determine either identical or comparable critical CTOA values for stable ductile crack growth using the SENB specimens. A constraint-corrected CTOA resistance curve and a constraint-corrected critical CTOA equation are also obtained for A285 carbon steel.

Research Organization:
Savannah River Site (SRS), Aiken, SC (United States); Savannah River National Lab (SRNL), Aiken, SC (United States)
Sponsoring Organization:
USDOE Office of Environmental Management (EM); USDOE Laboratory Directed Research and Development (LDRD) Program
Grant/Contract Number:
89303321CEM000080
OSTI ID:
1899552
Alternate ID(s):
OSTI ID: 1962949
Report Number(s):
SRNL-STI-2022-00343
Journal Information:
Engineering Fracture Mechanics, Journal Name: Engineering Fracture Mechanics Vol. 271; ISSN 0013-7944
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (32)

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