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Title: Intergranular fracture in UO{sub 2}: derivation of traction-separation law from atomistic simulations

Conference ·
OSTI ID:22264186
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  1. Fuels Modeling and Simulation Department, Idaho National Laboratory - INL, Idaho Falls, ID 83415 (United States)

In this study, the intergranular fracture behavior of UO{sub 2} was studied by molecular dynamics simulations using the Basak potential. In addition, the constitutive traction-separation law was derived from atomistic data using the cohesive-zone model. In the simulations a bicrystal model with the (100) symmetric tilt Σ5 grain boundaries was utilized. Uniaxial tension along the grain boundary normal was applied to simulate Mode-I fracture. The fracture was observed to propagate along the grain boundary by micro-pore nucleation and coalescence, giving an overall intergranular fracture behavior. Phase transformations from the Fluorite to the Rutile and Scrutinyite phases were identified at the propagating crack tips. These new phases are metastable and they transformed back to the Fluorite phase at the wake of crack tips as the local stress concentration was relieved by complete cracking. Such transient behavior observed at atomistic scale was found to substantially increase the energy release rate for fracture. Insertion of Xe gas into the initial notch showed minor effect on the overall fracture behavior. (authors)

Research Organization:
American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
OSTI ID:
22264186
Resource Relation:
Conference: GLOBAL 2013: International Nuclear Fuel Cycle Conference - Nuclear Energy at a Crossroads, Salt Lake City, UT (United States), 29 Sep - 3 Oct 2013; Other Information: Country of input: France; 33 refs.; Related Information: In: Proceedings of GLOBAL 2013: International Nuclear Fuel Cycle Conference - Nuclear Energy at a Crossroads| 1633 p.
Country of Publication:
United States
Language:
English