31. Uncertainties of Digital Image Correlation Due to Pattern Degradation at Large Strain

A method to measure the displacement uncertainty increase, due in part to pattern degradation at large strains, is described. The method is similar to rigid body displacement methods used in prior work. Multiple pattern assessment metrics from the literature are calculated for the same experiments to determine if the trends in the uncertainty are consistent with the trends seen in the metrics. The pattern assessments are carried out over the entire region of interest for correlation, but some of the metrics are based on the size of the correlation subset. The results show better agreement between the increase in displacement uncertainties and the subset size based metrics, than the metrics that measure the entire region of interest regardless of the subset size.