Relation of n-value to critical current in bent-damaged Bi2223 composite tape

The relation of n-value to critical current of bent-damaged (Bi,Pb)2Sr2Ca2Cu3O10+δ (Bi2223) composite tape was studied experimentally and analytically. The experimental results showed that, under bending strain, the n-value decreased rather slightly with decreasing critical current in comparison with the data obtained under applied tensile strain. The experimentally observed slight decrease in n-value with critical current under bending strain, and the measured changes in critical current and n-value with increasing bending strain, were described satisfactorily by the presented damage evolution model that correlates the extent of damage to variation of bending strain-induced tensile strain in the core along the thickness direction.