Effects of Particle Volume Fraction on the Macro-Thermo-Mechanical Behaviors in Plate-Type Dispersion Nuclear Fuel Elements

Abstract

In order to simulate the thermo-mechanical behaviors in a whole dispersion nuclear fuel plate, the macro-equivalent thermo-mechanical parameters for the composite fuel meat are obtained. The three-dimensional large deformation constitutive relations in the corotational coordinate system are developed for the component materials, and the stress update algorithms and numerical simulation methods are built allowing for the non-homogeneous irradiation conditions through forming UMAT subroutines in ABAQUS. The numerically obtained thermo-mechanical results for the two cases with the fuel particle volume fraction being 20% and 30% demonstrate that (1)the thermo-mechanical responses are of heterogeneity along the length direction; (2)the thermo-mechanical behaviors are strongly affected by the fuel particle volume fraction in the fuel meat; (3) the maximum Mises stress in the cladding becomes much higherfor the case with larger particle volume fraction, which may cause its fracture earlier at highburnup