Influence of tensile damage on V-I curve and critical current of DyBCO coated conductor

The coated conductors are subjected to mechanical and electromagnetic stresses in preparation and service. When the stress is high, the coated layer is damaged, resulting in loss of superconducting property. The present work was carried out to reveal the influence of tensile damage on V-I curve, critical current and n-value of DyBa2Cu3O7−δ coated conductor. The changes of the V-I curve, critical current and n-value with increasing applied tensile strain were measured experimentally. The features of the shift of the V-I curve to the lower current range and increase in its curvature, and accordingly the decrease in critical current and n-value, with increasing applied strain, were detected. For analysis of the experimental results, the model of Fang et al, which treats with the voltage generation due to the current shunting under existent crack, was applied. The experimentally observed features were described satisfactorily.