Dependence on Strain Rate and Temperature Shown by Yield Stress of Uranium Dioxide

Experimental characterization and modeling of UO 2 grain boundary cracking at high temperatures and high strain rates

“…(4), (12), (13), (18) and (19) has been solved in finite strain computations using a hypoelastic eulerian formulation provided by the Cast3M finite element solver. Cast3M implementation is close to the one described by Simo and Hugues [44].…”

“…In this respect, micromechanical numerical simulations of UO 2 show that strain incompatibilities between the grains can lead locally to tensile stresses [17,18] of microcracking. In strain-driven compression tests, it is well known that the yield stress increases with the strain rate [19,20]. This may explain why high strain rates trigger grain boundary cracking [14].…”

Reliability analysis of dispersion nuclear fuel elements

“…The thermal expansion of UO 2 fuel particles can be expressed as [17] Dl=l ¼ À3:0289 Â 10 À4 þ 8:4217 Â 10 À6 T þ 2:1481 Â 10 À9 T 2 ;…”

“…The Mises hardening rule of UO 2 fuel particles is as the following [17]: r ¼ 66:9 À 0:0397 Á T þ ð520:0 À 0:386 Á T Þ Á e p ; T 6 1200 C 36:6 À 0:0144 Á T þ ð139:…”

RANNS Code Analysis on the Local Mechanical Conditions of Cladding of High Burnup Fuel Rods under PCMI in RIA-Simulated Experiments in NSRR

“…The MATPRO-11 models 10) are adopted for specific heat, Young's modulus, thermal expansion, and pellet creep rate, while the Halden model 16) is applied to the pellet thermal conductivity and Tachibana's equation 17) to pellet yield stress. However, for cladding yield stress model, the MATPRO-11 model is modified so that the yield stress level attains maximum at the fluence of 2:6Â10 25 n/m 2 , and holds this level for larger fluence.…”