International round Robin test for mechanical properties of BSCCO-2223 superconductive tapes at room temperature

Abstract International RRT was carried out in order to establish the test method for mechanical properties of commercial BSCCO superconductive tapes under cooperation of seven research laboratories. From the stress versus strain curve, the following quantities were evaluated; modulus of elasticity, 0.2% proof strength, fracture strength and stresses at fixed strains. The scatter of measured values was analyzed by evaluating the relative standard uncertainty ( RSU ), which is the standard uncertainty divided by the average. The expected value of RSU for N  = 3 was derived for each mechanical quantities. In order to make clear the major contribution to the scatterings, the F test was applied. The major source of RSU ’s was attributed mostly to the influence of inter-laboratory scattering.