Title :
Theoretical Modeling for the Effect of Twisting on the Properties of Multifilamentary
Superconducting Strand
Author :
Ze Jing ; Huadong Yong ; Youhe Zhou
Author_Institution :
Dept. of Mech. & Eng. Sci., Lanzhou Univ., Lanzhou, China
Abstract :
In this paper, a theoretical model based on the micromechanics method is proposed to analyze the strain distribution and the performance degradation of bronze route Nb3Sn superconducting strand due to thermal strain and external loads. The effect of twisting on the Nb3Sn superconducting strand is considered. The strain distribution in the filament is analyzed by applying the Mori-Tanaka method. The critical parameters characterizing the superconducting properties of Nb3Sn filaments are discussed by using the model proposed by Markiewicz. It is found that twisting of the filaments has a significant effect on the stress-strain distribution. When the pitch length is not large enough compared to the strand diameter, it has a significant effect on the performance degradation. Moreover, the shorter the twist pitch, the higher the degradation of the critical parameters. When the pitch length is much larger than the strand diameter, it has little influence on the performance degradation.
Keywords :
niobium compounds; superconducting cables; Mori-Tanaka method; Nb3Sn; bronze route superconducting strand; external loads; filament; micromechanics method; multifilamentary superconducting strand properties; stress-strain distribution; thermal strain; twisting effect; Degradation; Matrices; Niobium-tin; Strain; Superconducting magnets; Tensile stress; Critical parameters; performance degradation; stress and strain; superconducting strand; thermal load; twisting effect;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2012.2232922