Intergranular fracture in UO2: Derivation of traction-separation law from atomistic simulations

Yongfeng Zhang, Paul C. Millett, Michael Tonks, Xian Ming Bai, S. Bulent Biner

Research output: Contribution to conferencePaperpeer-review


In this study, the intergranular fracture behavior of UO2 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.

Original languageEnglish (US)
Number of pages8
StatePublished - Jan 1 2013
EventInternational Nuclear Fuel Cycle Conference: Nuclear Energy at a Crossroads, GLOBAL 2013 - Salt Lake City, UT, United States
Duration: Sep 29 2013Oct 3 2013


OtherInternational Nuclear Fuel Cycle Conference: Nuclear Energy at a Crossroads, GLOBAL 2013
Country/TerritoryUnited States
CitySalt Lake City, UT

All Science Journal Classification (ASJC) codes

  • Energy Engineering and Power Technology
  • Nuclear Energy and Engineering


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