Title: Deterministic and probabilistic approaches to fatigue crack growth in nuclear pressure vessels

Authors: A.S. Francisco, P.F. Frutuoso e Melo

Addresses: Departamento de Ciencia dos Materiais, Escola de Engenharia Industrial Metalurgica de Volta Redonda, Universidade Federal Fluminense, Av. dos Trabalhadores, 420, 27255-250 Volta Redonda, RJ, Brazil. ' Programa de Engenharia Nuclear, COPPE, Universidade Federal do Rio de Janeiro, 21945-970, Rio de Janeiro, RJ, Brazil

Abstract: This paper presents some approaches to the fatigue crack growth in nuclear pressure vessels for failure probability calculation. According to the Thomson methodology, the crack growth is the physical process in which the time is explicitly involved in the structural failure of the pressure vessel. Since the crack growth laws are of deterministic nature, we first obtain the failure probability considering a deterministic approach. Next, probabilistic approaches are applied to calculate the failure probability based on the fact that the fatigue crack growth is a random process. Here, we use a probability distribution function to represent the failure process if the random behaviour is due only to the variability of experimental data. Next, we propose a stochastic approach for the failure probability calculation when the random nature of the crack growth along the time must be taken into account. The result of a simple problem shows that the stochastic approach is the most accurate one.

Keywords: crack growth; fatigue; nuclear pressure vessels; structural reliability; nuclear energy; nuclear power; failure probability.

DOI: 10.1504/IJNEST.2007.014649

International Journal of Nuclear Energy Science and Technology, 2007 Vol.3 No.2, pp.110 - 117

Published online: 23 Jul 2007 *

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