The analysis of underclad cracks in large-scale tests using the local approach to cleavage fracture

Conference · Mon Dec 01 04:00:00 EST 1997

OSTI ID:544231

Moinereau, D; Rousselier, G ^[1]

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1. Electricite de France, Moret-sur-Loing (France). Research and Development Branch

Electricite de France has conducted a large program including experiments on large-size cladded specimens and their interpretations to evaluate different methods of fracture analysis used in French safety studies regarding the risk of fast fracture in reactor pressure vessels. Four specimens made of ferritic steel A508 C13 with stainless steel cladding, containing small artificial underclad defects, have been tested in four-point bending. Experiments have been conducted at very low temperature, and crack instability by cleavage fracture without crack arrest was obtained in base metal. The tests have been interpreted using the local approach to cleavage fracture (Weibull model) by two-dimensional finite element computations. The Weibull model parameters have been determined using axisymmetrical notched specimens. The probability of failure has been evaluated in each test using finite element analyses with varying mesh sizes. The results show an important effect of the size of the elements at the crack tip on the calculated probability of failure. Those effects are confirmed using the model of a CT specimen. Also discussed is the shallow flaw effect with the Weibull model.

• OSTI ID: 544231
• Report Number(s): CONF-950618--
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
36 MATERIALS SCIENCE
CRACK PROPAGATION
DEFECTS
FRACTURE PROPERTIES
HARD FACING
MATHEMATICAL MODELS
MECHANICAL TESTS
PRESSURE VESSELS
REACTOR VESSELS
STEEL-ASTM-A508