PSI - Issue 71

Prakash Bharadwaj et al. / Procedia Structural Integrity 71 (2025) 26–33

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2. The material demonstrates hardening behaviour at 300 °C, leading to a reduced CPZ value as compared to RT. 3. Effect of the crack size on the location of maximum and minimum stress triaxiality ahead of the crack, is marginal. 4. The location adjacent to the crack tip experiences a greater accumulation of ratchet strain. Early retard was observed at the maximum triaxiality location and 300 °C, with respect to the other simulated cases. 5. At a fixed location in front of the crack tip, R = -1 results in lesser plastic strain accumulation rate relative to R = 0.1, for a given temperature. Strain accumulation is less at RT compared to 300 °C for a given R. References A. Moris Devotta, P.V. Sivaprasad, T. Beno, M. Eynian, K. Hjertig, M. Magnevall, M. Lundblad, A modified johnson-cook model for ferritic-pearlitic steel in dynamic strain aging regime, Metals (Basel). 9 (2019) 528. P. Lacombe, L’effet portevin -le chatelier ses caractéristiques et ses conséquences sur les hétérogénéités de déformation plastique, Matériaux Tech. 73 (1985) E5 – E19. D. Wagner, J.C. Moreno, C. Prioul, J.M. Frund, B. Houssin, Influence of dynamic strain aging on the ductile tearing of C-Mn steels: Modelling by a local approach method, J. Nucl. Mater. 300 (2002) 178 – 191. J.H. Yoon, B.S. Lee, Y.J. Oh, J.H. Hong, Effects of loading rate and temperature on J – R fracture resistance of an SA516-Gr. 70 steel for nuclear piping, Int. J. Press. Vessel. Pip. 76 (1999) 663 – 670. M. Srinivas, G. Malakondaiah, K.L. Murty, P.R. Rao, Fracture toughness in the dynamic strain ageing regime, Scr. Metall. Mater. 25 (1991) 2585 – 2588. K.G. Samuel, V. Ganesan, K.B.S. Rao, S.L. Mannan, H.S. Kushwaha, Strain controlled LCF behaviour of SA-333 Gr 6 piping material in the range 298 – 673 K, Int. J. Press. Vessel. Pip. 81 (2004) 973 – 981. P.K. Singh, J. Chattopadhyay, H.S. Kushwaha, S. Tarafder, V.R. Ranganath, Tensile and fracture properties evaluation of PHT system piping material of PHWR, Int. J. Press. Vessel. Pip. 75 (1998) 271 – 280. S. V Kamat, M. Srinivas, P.R. Rao, Effect of temperature on the mode I and mixed mode I/III fracture toughness of SA333 steel, Mater. Sci. Eng. A 528 (2011) 4141 – 4146. G. Kumar, A. Kumar, H.N. Bar, Effect of dynamic strain aging on cyclic deformation in piping material SA333 Gr-6 steel, Int. J. Press. Vessel. Pip. 194 (2021) 104529. A.T. Taddesse, S.-P. Zhu, D. Liao, B. Keshtegar, Cyclic plastic zone-based notch analysis and damage evolution model for fatigue life prediction of metals, Mater. Des. 191 (2020) 108639. B.O. Chikh, A. Imad, M. Benguediab, Influence of the cyclic plastic zone size on the propagation of the fatigue crack in case of 12NC6 steel, Comput. Mater. Sci. 43 (2008) 1010 – 1017. G.R. Irwin, Plastic Zone Near a Crack Tip and Fracture Toughness, Sagamore Ordnance Material Conference, pp, Used Meas. Indirect Tensile Strength Rocks. Rock Mech. Rock Eng. 48 (1960) 1849 – 1866. P.F. Gao, Z.N. Lei, X.X. Wang, M. Zhan, Deformation in fatigue crack tip plastic zone and its role in crack propagation of titanium alloy with tri-modal microstructure, Mater. Sci. Eng. A 739 (2019) 198 – 202. P. Bharadwaj, S.K. Gupta, J. Chattopadhyay, Study of cyclic plastic zone ahead of the fatigue crack tip using Digital Image Correlation system, Procedia Struct. Integr. 60 (2024) 655 – 664. R. Hosseini, R. Seifi, Fatigue crack growth determination based on cyclic plastic zone and cyclic J-integral in kinematic – isotropic hardening materials with considering Chaboche model, Fatigue Fract. Eng. Mater. Struct. 43 (2020) 2668 – 2682. S.K. Paul, S. Tarafder, Cyclic plastic deformation response at fatigue crack tips, Int. J. Press. Vessel. Pip. 101 (2013) 81 – 90. J.L. Chaboche, Time-independent constitutive theories for cyclic plasticity, Int. J. Plast. 2 (1986) 149 – 188. G. Kumar, H.N. Bar, A. Kumar, S. Sivaprasad, A comparative assessment of cyclic deformation behavior of SA333 Gr-6 steel at ambient and elevated temperatures, Int. J. Mater. Res. 110 (2019) 1000 – 1009. T.L. Anderson, T.L. Anderson, Fracture mechanics: fundamentals and applications, CRC press, 2005. S.K. Paul, Numerical models of plastic zones and associated deformations for a stationary crack in a C(T) specimen loaded at different R-ratios, Theor. Appl. Fract. Mech. 84 (2016) 183 – 191. S. Suresh, Fatigue of Materials, 2nd ed., Cambridge University Press, Cambridge, 1998. N.E. Dowling, Mean stress effects in stress-life and strain-life fatigue, SAE Technical Paper, 2004.