Micro-cantilever beam experiments and modeling in porous polycrystalline UO2

Understanding the impact of microstructure on thermo-mechanical behavior oxide nuclear fuels is vital to predicting their performance through multiscale models. Evaluating mechanical properties at sub-grain length scale key developing these In this work, 3D finite element (FE) models were constructed simulate micrometer-scale bending micro-cantilever beams fabricated using porous polycrystalline uranium dioxide (UO2) and tested room temperature. The results showed that porosity elastic anisotropy individual grains can play a significant role in determining effective material deduced from tests. Specifically, had non-negligible effect, given pore size was same order magnitude as dimensions micro-beams. Correlations between load-deflection data, location, (effective Young's modulus) investigated UO2 micro-beam FE models, where clusters included placed different locations along beam. Results indicated presence near substrate, i.e., clamp beam, has strongest effect behavior, with leading reduction stiffness largest for any location clusters. Furthermore, it also found located towards middle span close end beam have comparatively small behavior. Therefore, concluded accurate estimates modulus be obtained experiments after accounting one third clamp. This, turn, provides an avenue improve microscale analysis porous, anisotropic materials.