Crack tip plasticity in single crystal UO 2: Atomistic simulations

Yongfeng Zhang, Xiang Yang Liu, Paul C. Millett, Michael Tonks, David A. Andersson, Bulent Biner

Research output: Contribution to journalArticlepeer-review

28 Scopus citations


The fracture behavior of single crystal uranium dioxide under mode-I loading is studied using molecular dynamics simulations at room temperature. The initial cracks are introduced as elliptical notches on either {1 1 1} or {1 1 0} planes. Two crack tip shielding mechanisms, dislocation emission and metastable phase transformation are identified. Crack extension is observed for cracks residing on {1 1 1} plane only. The dislocations have a Burgers vector of 〈1 1 0〉/2 and glide on {1 0 0} planes. Two metastable phases, Rutile and Scrutinyite, are identified during the phase transformation, and their relative stability is confirmed by separate density-functional-theory calculations. Examination of stress field near the crack tips reveals that dislocation emission is not as an effective shielding mechanism as the phase transformation. The formation of new phases may effectively shield the crack if all phase interfaces formed near the crack tips are coherent, as in the case of cracks residing on {1 1 0} planes.

Original languageEnglish (US)
Pages (from-to)96-105
Number of pages10
JournalJournal of Nuclear Materials
Issue number1-3
StatePublished - Nov 2012

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Materials Science(all)
  • Nuclear Energy and Engineering


Dive into the research topics of 'Crack tip plasticity in single crystal UO 2: Atomistic simulations'. Together they form a unique fingerprint.

Cite this