In the reliable region where (λphase /aFF) > 3, the fitting parameters of the master curve have around 5 % error on λpred and less than 10% error on E0. In the inapplicable region, however, where (λphase /aFF) < 2, λpred and E0 depend sensitively on the fitting parameters. This analysis suggests that the use of the universal parameters from the FEA master curve is appropriate as long as (λphase /aFF) > 3, i.e., is in the reliable region.