Three-Dimensional Finite Element Analyses of Thin-Sliced Compact Tension Specimens of Irradiated Zr-2.5Nb Materials With Consideration of Split Circumferential Hydrides

In this paper, the low energy mode associated with split circumferential hydrides is examined by conducting three-dimensional finite element analyses of thin-sliced compact tension (CT) specimens of irradiated Zr-2.5Nb materials with split circumferential hydrides. Finite element models of thin-sliced CT specimens with split circumferential hydrides and various slice thicknesses are developed with the assumption of the plane strain condition in the thickness direction except in the split circumferential hydride regions. The computational results indicate that with split circumferential hydrides, the crack tip opening displacement (CTOD) can increase 50% for thinner thin-sliced specimens under the same load per unit thickness. With the use of a strain-based failure criterion with split circumferential hydrides, the load per unit thickness for thinner thin-sliced specimens can reduce by at most 70% to meet the failure criterion.