Critical transport currents of Bi(2223)/Ag tapes under axial and bending strain

The transport critical current of Bi(2223)/Ag tapes depends on the mechanical stress applied during or before j(c) determination. We previously reported on our reinforced tapes with a yield strength of 300 - 350 MPa[1], which is more than 5 times the value for conventional Ag-sheathed tapes. The maximum tolerable strain is increased from about 0.3% to 0.7 - 0.8% for the modified tapes. In this contribution we extend our investigations on the variation of filament number and filament/matrix ratio and other sheath materials, e.g. AgAu. We discuss the situations for axial tensile-, hoop- and bending stress. For the special case of bending strain a carbon fibre reinforcement enhances the mechanical performance of the tapes.