b'Figure 2. Engineering stress vs. displacement curves of C26M welded material measured though no-gauge ring pull tests using a mandrel diameter of 3.0, 4.0, 4.5, 5.1, 6.8, or 8.5 mm as well as uniaxial tension testssupports the Department of Energyaddition, cladding tubes come in a (DOE) objectives of safe, reliable andrange of diameters and thicknesses.Mechanical evaluation thereby economical operation of theFigure 2 shows how the stress strainof cladding tubes is nations current reactor fleet.curves change with different mandrelnot straight forward, The second component of the projectdiameters. When interpreting pastthis work package investigated the interpretation ofresults and planning future ringpulldeveloped and tested ringpull test data. Specifically, we usedtests, understanding the impact of thenew ringpull testing digital image correlation (DIC) toratio of mandrel and tube diameters isprotocols that have measure local strains to interpret thecritical to meet DOE objectives. shown to extract load/displacement data from the tests.Accomplishments: mechanical properties This interpretation was done with aThe project goals were achieved byfrom accident tolerant systematic study on a range of ringpullringpull testing both Zircaloy andfuel claddings.fixture mandrel sizes chosen based onFeCrAl cladding tubes using our newly our analytical strain calculations. Thisdeveloped fixture, Figure 3, on our component of the project is importanthotcell friendly and miniature load because different institutions useframe, Figure 1. During the ringpull different ringpull test fixtures that cantesting we were able to extract the yield have different mandrel diameters. Inand ultimate tensile strength of the 2021|AFC ACCOMPLISHMENTS 115'