Thermomechanical analysis of thermal shock fracture in the brittle/ ductile transition zone - Part II: Numerical calculations and interpretation of the test results

M. Reytier (1) , S. Chapuliot (1) , S. Marie (1) , M. Nédelec

1 LISN - Laboratoire d'Intégrité des Structures et de Normalisation

The integrity of PWR pressure vessels is assured by keeping the crack tip stress intensity factor below the toughness of the material under monotonic isothermal loading. To study the effects of sudden cooling associated with a thermal gradient, a specially modified compact specimen has been developed. This has been used to carry out tests in the transition zone with different loading-temperature sequences liable to call the conventional criteria into question. The test is described in detail in Part I of this article [Chapuliot S, et al. Thermomechanical analysis of thermal shock fracture in the brittle/ ductile transition zone. Part I: Description of the tests. Engng Fract Mech, 72, 2005, 661-73]. The second part describes numerical investigations to estimate the local mechanical fields at the crack tip and the overall parameters of the fracture mechanics. Finite element thermomechanical calculations are used to interpret the results of these new thermal shock tests using the master curve concept [ASTM E 1921-1997. Standard test method for determination of reference temperature To for ferritic steels in the transition range, 1997] and the Beremin statistical model [Beremin FM. A local criterion for cleavage fracture of a nuclear pressure vessel steel. Metall Trans A, 14A, November 1983, 2287-777]. © 2005 Elsevier Ltd. All rights reserved.

Mots clés: Brittle fracture; Ductile fracture; Finite element method; Fracture toughness; Mathematical models; Pressure vessels; Pressurized water reactors; Statistical methods; Steel; Stress intensity factors; Thermoanalysis; Beremin model; Crack tip stress intensity factor; Ferritic steels; Local approach; Nuclear pressure vessel steel; Thermal shock fracture; Thermomechanical shocks; Fracture mechanics; fracture mechanics

Domaines: Physique [physics]

M. Reytier, S. Chapuliot, S. Marie, M. Nédelec. Thermomechanical analysis of thermal shock fracture in the brittle/ ductile transition zone - Part II: Numerical calculations and interpretation of the test results. Engineering Fracture Mechanics, 2006, 73 (3), pp.283-295. ⟨10.1016/j.engfracmech.2004.07.016⟩. ⟨hal-03018236⟩