Development of fracture toughness reference curves

Journal Article · Tue Jan 01 04:00:00 EST 1980 · J. Eng. Mater. Technol.; (United States)

DOI:https://doi.org/10.1115/1.3224767· OSTI ID:6360076

Oldfield, W

A large base of K/sub IC/, K/sub Id/ and J/sub IC/ (R-curve) fracture toughness data has been used to develop reference toughness curves. The most successful results were obtained when a sigmoidal function was fitted to data from which the heat-heat variation in both the temperature and fracture toughness had been reduced by referencing. Several referencing procedures have been studied, but the only one found to be successful in this work was based upon the precracked instrumented Charpy V-notch test. The tanh function K = A + B tanh (T - To/C) (K = toughness, T = temperature, and A, B, T/sub 0/ and C are coefficients which give the best fit between curve and data) fitted to precracked instrumented Charpy V-notch test data provided suitable referencing quantities. Using the coefficients A and B to reference fracture toughness, and T/sub 0/ and C to reference temperature, lower bound reference curves were developed. Weighted, nonlinear regression procedures were used to define lower bound reference toughness curves for each of three stress intensification rates. The lower bound was the statistical global tolerance bound to the referenced data. The reference curves can be readily used to define a lower bound relationship between fracture toughness and temperature for nuclear pressure vessel steel on the basis of a set of precracked instrumented Charpy V-notch tests.

• Research Organization: Materials Research and Computer Simulation, Goleta, CA
• OSTI ID: 6360076
• Journal Information: J. Eng. Mater. Technol.; (United States), Journal Name: J. Eng. Mater. Technol.; (United States) Vol. 102; ISSN JEMTA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CHARPY TEST
DESTRUCTIVE TESTING
FRACTURE PROPERTIES
IMPACT TESTS
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
STEEL-ASTM-A533
STEELS
TEMPERATURE DEPENDENCE
TESTING