Sample capacity and anvil size effects for a standardized method to determine the delamination strength of 2G HTS coated conductors

Anvil tests are effective for determination of the mechanical delamination strength (MDS) of 2G high temperature superconducting coated conductors (CCs), which has been widely used. However, the discrete property of measurement data makes the MDS of CCs hard to evaluate just from the average and variance. To properly provide an analysis of these discrete experimental data, the three-parameter Weibull distribution analysis along with its reliability function has been adopted, from the criterion of 99% reliability, the obtained MDS is conveniently referred for both engineering test and design. Nevertheless, the stable and reliable Weibull distribution analysis should be based on enough sample capacity and proper anvil size. In this work, the influences of anvil size and sample capacity on the reliability function of Weibull distribution analysis for MDS determination were systematically investigated at 77K. It is found that the minimum of sample capacities for Weibull distribution analysis are different with different anvil sizes. From the aspects of energy dissipation and cost consumption, we recommend the full width size of anvils to be utilized to obtain the justified MDS of CCs without being slitted.