Multi-scale modeling of inter-granular fracture in UO2

Chakraborty, Pritam¹  Zhang, Yongfeng¹  Tonks, Michael R.¹  Biner, S. Bulent¹ 

[1] Idaho National Lab. (INL), Idaho Falls, ID (United States)

关键词: Brittle;    Fracture;    Intergranular;    Molecular dynamics;    Multiscale modeling;    Phase-field;   

DOI  :  10.2172/1177228
RP-ID  :  INL/EXT--14-33190
PID  :  OSTI ID: 1177228

美国|英语

来源: SciTech Connect

【 摘 要 】

A hierarchical multi-scale approach is pursued in this work to investigate the influence of porosity, pore and grain size on the intergranular brittle fracture in UO2. In this approach, molecular dynamics simulations are performed to obtain the fracture properties for different grain boundary types. A phase-field model is then utilized to perform intergranular fracture simulations of representative microstructures with different porosities, pore and grain sizes. In these simulations the grain boundary fracture properties obtained from molecular dynamics simulations are used. The responses from the phase-field fracture simulations are then fitted with a stress-based brittle fracture model usable at the engineering scale. This approach encapsulates three different length and time scales, and allows the development of microstructurally informed engineering scale model from properties evaluated at the atomistic scale.