February AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | F E B R U A R Y / M A R C H 2 0 1 9 3 0 results for J q and tearing modulus de- rived from J-R curves. Automated J-R curve analysis software yields results essentially identical to those from the manual analysis method. Small differ- ences between the two analysis routes are due to the software stopping itera- tive normalization function fitting when the deviation between normalization function fit and the final normalized load is less than 0.5% of the final nor- malized load, whereas any deviation less than 1% for manual analysis is ac- ceptable per ASTM E1820. Figure 6 shows J-R curve results derived from the same specimen using software normalization analysis, manu- al normalization analysis, and the EUC method. J-R curve results from software and manual normalization analyses al- most overlap, while small differences are observed between the normaliza- tion method and the EUC method due to differences in determining crack siz- es between the two methods. ~AM&P Note: MATLAB is a registered trademark of MathWorks, Natick, Mass. For more information: Xiang (Frank) Chen is a research staff member, Nu- clear Materials Science and Technology Group, Materials Science and Technol- ogy Div., Oak Ridge National Laborato- ry, P.O. Box 2008, MS-6136, Oak Ridge, TN, 37831-6136, 865.574.5058, chenx2@ ornl.gov. Acknowledgment This research was sponsored by the U.S. Department of Energy (DOE), Office of Nuclear Energy, Light Water Reactor Sustainability Program, Mate- rials Research Pathway, under contract DE-AC05-00OR22725 with UT-Battelle LLC/Oak Ridge National Laborato- ry (ORNL). It was supported in part by an appointment to the Oak Ridge National Lab- oratory HERE Program, sponsored by the DOE and administered by the Oak Ridge Institute for Science and Educa- tion. The authors thank the following ORNL col- leagues: Keith Leonard for his programmatic sup- port, Lizhen Tan and Wei Tang for technical review of this manuscript, and Jungwon Kim for his as- sistance in setting up the Gitlab webpage for host- ing the software. References 1. X. Chen, et al., AM&P, 172, p 19-23, 2014. 2. Standard Test Meth- od for Measurement of Fracture Toughness, E1820-18, ASTM, 2018. 3. R. Herrera and J.D. Landes, Fracture Mechanics: 21st Symposium, STP 1074, J.P. Gudas, J.A. Joyce, and E.M. Hackett, Eds., p 24-43, ASTM, 1990. 4. J.D. Landes, et al., JTEVA, 19, p 305- 311, 1991. 5. J.A. Joyce, JTEVA, 29, p 329-351, 2001. 6. K. Lee, Elastic-Plastic Fracture Toughness Determination Under Some Difficult Conditions, Ph.D. disserta- tion, University of Tennessee, Knoxville, 1995. 7. C.E. Turner, The Eta Factor, Post Yield Fracture Mechanics, 2nd ed., Elsevier Applied Science Publishers, p 451, 1984. 8. L.N. Clowers, A.E. Linares, and X. Chen, Technical Manual for Auto- mated J-R Curve Analysis Program Based on the ASTM E1820-18 Nor- malization Method, ORNL/LTR-2018/ 1041, Oak Ridge National Laboratory, Tenn., 2018. 9. P.C. Paris, et al., Elastic-Plastic Fracture, STP 668, J.D. Landes, J.A. Begley, and G.A. Clarke, Eds., p 5-36, 1979. Fig. 6 — Comparison of J-R curve results from three different analysis routes for the same specimen.