New probabilistic fracture mechanics approach with neural network-based crack modeling: Its application to multiple cracks problem

Conference · Wed Nov 01 00:00:00 EST 1995

OSTI ID:122630

Yoshimura, Shinobu; Lee, J S; Yagawa, Genki ^[1]; Sugioka, Kiyoshi; Kawai, Tadahiko ^[2]

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1. Univ. of Tokyo (Japan)
2. Science Univ. of Tokyo (Japan)

Studies on efficient utilization and life extension of operating nuclear power plants (NPPs) have become increasingly important since ages of the first-generation NPPs are approaching their design lives. In order to predict a remaining life of each plant, it is necessary to select those critical components that strongly influence the plant life, and to evaluate their remaining lives by considering aging effects of materials and other factors. This paper proposes a new method to incorporate sophisticated crack models, such as interaction and coalescence of multiple surface cracks, into probabilistic fracture mechanism (PFM) computer programs using neural networks. First, hundreds of finite element (FE) calculations of a plate containing multiple surface cracks are performed by parametrically changing crack parameters such as sizes and locations. A fully automated 3D FE analysis system is effectively utilized here. Second, the back-propagation neural network is trained using the FE solutions, i.e. crack parameters vs. their corresponding stress intensity factors (SIFs). After a sufficient number of training iterations, the network attains an ability to promptly output SIFs for arbitrary combinations of crack parameters. The well trained network is then incorporated into the parallel PFM program which runs on one of massively parallel computers composed of 512 processing units. To demonstrate its fundamental performances, the present computer program is applied to evaluate failure probabilities of aged reactor pressure vessels considering interaction and coalescence of two dissimilar semi-elliptical surface cracks.

• OSTI ID: 122630
• Report Number(s): CONF-950740-; ISBN 0-7918-1335-5; TRN: 95:024247
• Resource Relation: Conference: Joint American Society of Mechanical Engineers (ASME)/Japan Society of Mechanical Engineers (JSME) pressure vessels and piping conference, Honolulu, HI (United States), 23-27 Jul 1995; Other Information: PBD: 1995; Related Information: Is Part Of Fatigue and fracture mechanics in pressure vessels and piping. PVP-Volume 304; Mehta, H.S.; Wilkowski, G.; Takezono, S.; Bloom, J.; Yoon, K.; Aoki, S.; Rahman, S.; Nakamura, T.; Brust, F.; Yoshimura, S. [eds.]; PB: 594 p.
• Country of Publication: United States
• Language: English

Related Subjects

22 NUCLEAR REACTOR TECHNOLOGY
99 MATHEMATICS
COMPUTERS
INFORMATION SCIENCE
MANAGEMENT
LAW
MISCELLANEOUS
FRACTURE MECHANICS
NEURAL NETWORKS
NUCLEAR POWER PLANTS
PRESSURE VESSELS
SYSTEMS ANALYSIS
PARAMETRIC ANALYSIS
THREE-DIMENSIONAL CALCULATIONS
CRACK PROPAGATION
PARALLEL PROCESSING
SERVICE LIFE
COMPUTER CODES