PSI - Issue 2_A

Kiminobu Hojo et al. / Procedia Structural Integrity 2 (2016) 1643–1651 Hojo, Ogawa, Hirota et al./Structural Integrity Procedia 00 (2016) 000–000

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5. Conclusion In order to consider the constraint effect on DBTT region, fracture tests using NT and CT specimens were performed and several models which can handle this effect were applied to predict their fracture behaviours. As for damage mechanics model, GTN model predicted more precisely ductile crack growth of CT specimen with side grooves than Rousselier model. The parameter set of GTN model from one type of specimens could not simulate the fracture behaviour of the other’s. This means that the parameters dependence on the specimen type may exist. The coupled model could correlate σ Wc - K Jc curve in DBTT, but its prediction accuracy has to be improved. The authors have a plan to perform fracture toughness tests using flat plates with a surface flaw and the evaluation method will be verified. Acknowledgements Prof. Fumiyoshi Minami kindly gave very important and discerning advice to the authors. The authors sincerely acknowledge the scientific and technical advice of Prof. Minami for the research work. References Bernauer, G., Brocks, W., and Schmitt, W. , 1999, Modifications of the Beremin model for cleavage fracture in the transition region of a ferritic steel. Engineering Fracture Mechanics, 64(3), 305-325. Beremin, F. M., 1983, A Local Criterion for Cleavage Fracture of a Nuclear Pressrue Vessel Steel, Metallurgical Trans . A, 14A, 2277-2287. JEAC 4206 (2016ed.), Method of Verification Tests of the Fracture Toughness for Nuclear Pressure Vessels, The Japan Electric Association Code. Corre, V., Le, Chapliot, S., Degallaix, S., and Fissolo, A., Transferability of Cleavage Appearance Temperture from Laboratory Specimen to Structure, 2006, LOCAL APPROACH TO FRACTURE, EUROMECH-MECHAMAT 2006, 9 th European Mechanics of Materials Conference, Moret-sur-Loing. Eripret, C., Lidbury, D. P. G., Sherry, A., & Howard, I. , 1996, Prediction of fracture in the transition regime: application to an A533B pressure vessel steel. Le Journal de Physique IV, 6(C6), C6-315. Gao, X., Ruggieri, C., and Dodds Jr, R. H., 1998, Calibration of Weibull stress parameters using fracture toughness data. International Journal of Fracture, 92(2), 175-200. Gehrlicher, S., Seidenfuss, M., and Schuler, X., 2014, Further Development of the Nonlocal Damage Model of Rousselier for the Transition Regime of Fracture Toughness and Different Stress States. In ASME 2014 Pressure Vessels and Piping Conference (pp. V003T03A097 V003T03A097). American Society of Mechanical Engineers. Le Delliou, P., Moinereau, D., Keim, E., and Nicak, T., 2014, STYLE Project: Assessment of transferability of fracture material properties from specimens to large components by local approach to fracture. In ASME 2014 Pressure Vessels and Piping Conference (pp. V06AT06A049 V06AT06A049). American Society of Mechanical Engineers. Mudry, F., 1987, A Local Approach to Cleavage Fracture, Nuclear Engineering Design, 105, 65-76. Minami, F., Brückner-Foit, A., Munz, D., and Trolldenier, B.,1992, Estimation procedure for the Weibull parameters used in the local approach. International journal of fracture, 54(3), 197-210. Minami, F., Ohata, M., et al., Method of Constraint Loss Correction of CTOD Fracture Toughness for Fractrue Assesment of Steel Components, 2006, LOCAL APPROACH TO FRACTURE, EUROMECH-MECHAMAT 2006, 9 th European Mechanics of Materials Conference, Moret-sur-Loing. Ruggieri, C., Minami, F., and Toyoda, M., 1993, Effect of Mismatch on Crack Tip Stress Fields of HAZ-Notched Joints Subjected to Bending and Tension , Soc. Naval Archit. Japan, 174, 543-549. Samal, M. K., Seidenfuss, M., Roos, E., Dutta, B. K., & Kushwaha, H. S., 2008, Experimental and numerical investigation of ductile-to-brittle transition in a pressure vessel steel. Materials Science and Engineering: A, 496(1), 25-35. Shih, C. F., and Xia, L., 1995, Modeling Crack Growth Resistance Using Computational Cells with Microstructurally—Based Length Scales. In Constraint Effects in Fracture Theory and Applicatons: Second Volume. ASTM International. Tvergaard, V. (1982). On localization in ductile materials containing spherical voids. International Journal of Fracture, 18(4), 237-252. Wiesner, C. S. and Goldthorpe, M. R. , 1996, The Effect of Temperature and Specimen Geometry on the Parameters of the. Le Journal de Physique IV, 6(C6), C6-295. Yoshimoto, K., Hirota, T., Sakamoto, H., Sugihara, T., Sakaguchi, S., and Oumaya, T., 2013, Applicability of Miniature C (T) Specimen to Evaluation of Fracture Toughness for Reactor Pressure Vessel Steel. In ASME 2013 Pressure Vessels and Piping Conference (pp. V06BT06A056-V06BT06A056). American Society of Mechanical Engineers. Watanabe, D., and Hojo, K., 2014, Application of Gurson Model to Different Constraint Specimens. In ASME 2014 Pressure Vessels and Piping Conference (pp. V003T03A099-V003T03A099). American Society of Mechanical Engineers.